Structured optoelectronic component

Abstract

The present invention relates to an optoelectronic component, comprising a substrate, in particular a cover layer, an optoelectronically active layer and a contacting layer, its outer and / or inner surface having a structured region with a point structure composed of pins or inverse pins. Optical properties and wetting properties of the optoelectronic component can advantageously be set in a targeted manner by means of such a point structure. In this regard, it is possible, in particular, to improve the incoupling of light into, or the outcoupling of light out of, optoelectronic components and hence efficiency. The invention furthermore relates to an optoelectronic module, a method for producing an optoelectronic component, and the use of a structured substrate for an optoelectronic component.

Description

[0001] STRUCTURED OPTOELECTRONIC COMPONENT

[0002] TECHNICAL FIELD

[0003] The present invention relates to an optoelectronic component comprising a substrate, in particular a cover layer, an optoelectronically active layer, and a contacting layer, the outer and / or inner surface of which and / or within the volume, in particular within a plane within the volume, has a structured region with a dot structure of cones or inverse cones. Such a dot structure allows the optical properties and wetting properties of the optoelectronic component to be advantageously adjusted in a targeted manner. Furthermore, the invention relates to an optoelectronic module, a method for producing an optoelectronic component, and the use of a structured substrate for an optoelectronic component.

[0004] Optoelectronic components are used both for environmentally friendly energy generation using sunlight and for the efficient generation of electromagnetic radiation. Since one of the most important topics for future technology is energy generation from renewable sources combined with the efficient use of the generated energy, optoelectronic components offer great potential.

[0005] A shift away from fossil fuels is intended to reduce dependence on raw materials and reduce or eliminate the emission of climate-damaging gases, so photovoltaic components, also known as photovoltaic cells or solar cells, can make an important contribution here. Photovoltaics is a widely used energy generation technology that converts electromagnetic radiation into electrical energy. Photovoltaic cells and modules composed of multiple photovoltaic cells are used both as individual components in technical devices for direct power supply and as large systems for general electrical energy generation.

[0006] In addition to energy generation, another approach to the energy transition is saving electrical energy through efficient devices and lighting. For example, the use of light-emitting diodes (LEDs) has already replaced inefficient light sources such as incandescent bulbs. Both in energy generation using electromagnetic waves and in lighting that emits electromagnetic waves, the efficiency of the technology depends heavily on how well the electromagnetic waves can be coupled into the component (photovoltaics) or decoupled from it (LEDs). The transmission of light through the outer layers of the component is therefore a fundamental problem, the solution to which greatly influences the efficiency of such components.

[0007] Relevant factors for impairing efficient light output are the reflection occurring at the interface(s) on the layer materials and also absorption processes due to the presence of dirt particles.

[0008] For example, it is known from Klemens Ilse et al. ("Techno-Economic Assessment of Soiling Losses and Mitigation Strategies for Solar Power Generation" by Joule 3, pages 2303-2321, October 16, 2019, Elsevier Inc.) that soiling in photovoltaic systems with photovoltaic modules leads to efficiency losses of at least 3% to 4%. This already results in economic losses of 3 to 5 billion euros. Taking into account additional costs, such as the very complex cleaning of such systems, some estimates even assume values ​​of up to 7 billion euros.

[0009] Reflection losses that occur at existing interfaces also reduce the proportion of electromagnetic radiation used or to be used.

[0010] STATE OF THE ART

[0011] There are various approaches to optimizing the components in order to improve the proportion of electromagnetic waves that can penetrate the outer layers and thus optimize the optical properties of the components.

[0012] For example, the encapsulations of photovoltaic components are coated with an anti-reflective layer. Structured anti-reflective films are also known, which are subsequently applied to the components and ensure that a larger proportion of the light is coupled into photovoltaic components, thus increasing their efficiency.

[0013] An anti-reflective coating that can also be used for solar cells is also described in DE 196 42 419 A1. A porous coating is applied that has an anti-reflective effect. The disadvantage is that the materials used are environmentally harmful and costly. This negatively impacts both the ecological and economic balance of photovoltaic systems.

[0014] Coatings are also used to create anti-smudge properties on components. For example, such anti-smudge coatings are applied to the front glass. The disadvantage is that such coatings must be applied in addition to the other layers, which is complex and costly.

[0015] From a technological perspective, it's very important that such coatings with anti-soil properties are also optimized for optical effects. If only the anti-soil properties are optimized, there's a risk of a loss of efficiency due, for example, to high reflection caused by the use of the additional material layer.

[0016] However, coatings are also known that are optimized in many ways. For example, Jaesung Son, et al. ("A practical superhydrophilic self-cleaning and antireflective surface for outdoor photovoltaic applications" from Solar Energy Materials and Solar Cells, Volume 98, March 2012, pages 46-51) also describes a lithographic process that creates nanostructures by etching a coating and a mask arranged on top of it. The resulting coating ensures that the surface exhibits superhydrophilic and therefore self-cleaning properties as well as an anti-reflective effect. The disadvantage of creating such a coating is that it is very complex. Furthermore, the materials used for the coating and also for the etching process are costly and environmentally harmful.

[0017] US 2016 / 293781 A1 shows three-dimensional structures on solar cells that exhibit anti-reflection and hydrophobic properties. These are used to increase light coupling into solar cells and improve efficiency.

[0018] To create the structure, a nanoindentation arrangement is imprinted onto the surface of an electrochemically polished aluminum foil layer. A type of stamp is used to create the structures using wet-chemical etching by means of silicon nanopillars arranged in a hexagonal pattern. Unfortunately, the etching process results in uneven surfaces for the resulting structures, which reduces the reproducibility of the effects. Furthermore, the method used here lacks flexibility, as a new stamp arrangement is required for each adjustment of the structure size. A solar cell using a substrate incorporating an anti-reflection nanostructure is described in KR 20120060185 A. A manufacturing process is presented here that aims to minimize the amount of reflected light generated due to a refractive index difference between a substrate and air.For this purpose, an anti-reflective nanostructure with a cycle or an average spacing below an optical wavelength is formed on a solar cell substrate. The anti-reflective nanostructure is arranged periodically or aperiodically on both sides of a substrate and has an average spacing below an optical wavelength. A transparent conductive oxide layer is formed on the substrate, and a pin-type amorphous silicon layer is arranged on the transparent conductive electrode layer. A rear-side reflective layer is then formed on the pin-type amorphous silicon layer. A corresponding structure for application on a cover layer or protective layer is described in KR 2012 0060182 A.

[0019] To produce the cone-like anti-reflective coatings, an etching process is used in which metal particles arranged on the surface serve as a mask. The described spacings are in the range of less than 300 nm. Etching results in uneven and poorly defined structures. This, in turn, prevents suitable reproducibility of the properties. Furthermore, toxic materials are used in the etching processes.

[0020] A DLIP process used to structure a layer of aluminum zinc oxide (AZO) is described in A. Lasagni, et al. (“High speed surface functionalization rising direct laser interference patterning, towards 1 m2 / min fabrication speed with sub-pm resolution”, Proc. Of SPIE Vol. 8968 8968012-1 , 2014 SPIE). The laser interference structuring is carried out either with two partial beams or via a diffractive beam splitter (DBS), so that multiple partial beams are created. The resulting structures are either line-shaped or hexagonal. To create the hexagonal structures, line interference patterns are generated one after the other at a rotation angle of 60°. The disadvantage of this process is that it necessarily requires multiple irradiation. This makes it complex and error-prone.To adjust the interference period, the method presented here uses suitable lenses with corresponding focal lengths. This disadvantage means that adjusting the interference period is only possible for the existing lenses, and readjustment is required whenever the interference period is adjusted.

[0021] Document US 2018 / 006166 A1 describes a process for producing a metal-based solar absorber. The process described here can selectively improve solar absorption capacity. Furthermore, optimized thermal stability can be achieved. A laser interference lithography process is used for this purpose, in which a structure is etched into the material through a created mask. The disadvantage is that this process produces uneven structures and also involves the use of toxic materials.

[0022] An anti-reflection coating, particularly for solar cells, is disclosed in JP 2010 219495 A. The described structures have spacings of less than 400 nm or even less than 150 nm. Various methods are mentioned for creating the structures. For example, electron beam writing or laser interference are mentioned for structuring. The disadvantages of these methods are generally complex and slow.

[0023] EP 1 630 612 A2 describes an interference patterning process in which patterning is carried out using two superimposed partial beams. The laser wavelength used is shorter than that of visible light. However, in this case, a light-sensitive film is patterned, which then serves as a mask for etching. Disadvantages include the creation of uneven structures during etching, and the use of toxic materials in the process.

[0024] Structures that impart anti-reflective properties to a surface are also disclosed in EP 2 056 129 A1. However, the process used here is very complex and thus slow and inefficient. Furthermore, the structural parameters can only be varied with considerable effort.

[0025] TASK

[0026] The present invention is therefore based on the technical object of providing an optoelectronic component with improved efficiency which can be produced using a simple method.

[0027] It is also an object of the present invention to improve the optical properties of the optoelectronic component, while ensuring that the surface of the optoelectronic component is robust, particularly against external influences such as the environment and weather, and that the degradation of the materials over time is minimal. Furthermore, it is an object of the present invention to provide a method by which such optoelectronic components can be manufactured in a targeted and reliably reproducible manner with predetermined properties.

[0028] SOLUTION

[0029] This object is achieved by an optoelectronic component having the features of claim 1, as well as a module and a method having the features of the subordinate claims. Further advantageous embodiments can be found in the subclaims, the description, and the exemplary embodiments.

[0030] The object is achieved in particular by an optoelectronic component comprising a cover layer having an outer surface and an inner surface. The cover layer is at least partially transparent, preferably transparent, and the outer surface of the cover layer is designed to seal the optoelectronic component from the environment. Furthermore, the optoelectronic component comprises at least one functional layer, which is preferably an optoelectronically active layer or a contacting layer, which is arranged at least partially on the inner surface of the cover layer. The functional layer is thus preferably arranged adjacent to the cover layer.

[0031] Functional layers, in the sense of the invention, are layers that are crucial for the function of an optoelectronic component. These include boundary layers, optoelectronically active layers with pn junctions, optional barrier layers, or, according to the definition, contact layers.

[0032] According to the invention, the outer surface and / or the inner surface and / or in the volume, in particular within a plane in the volume, of the cover layer is formed from a structured and an unstructured region. The structured region has a first periodic dot structure, and the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi). The first interference pixel (10) has a periodic lattice of at least three, preferably seven, particularly preferably 19, cones or inverse cones with a first interference period (pi). The interference period of the first periodic dot structure is in the range from 50 nm to 50 pm, i.e. in the micrometer or submicrometer range. The structured region is formed by the different applied structures.These can be a single dot structure, multiple superimposed dot structures, or even superimposed dot and line structures. Even if the structured region consists of multiple, not necessarily interconnected, individual structured sub-regions, such as individual cones, the entire portion of the surface that is structured, whose surface has consequently changed due to treatment using a laser interference process, is considered a single structured region within the meaning of the invention. Thus, each surface can have only one structured region.

[0033] Any part of the surface that cannot be assigned to the structured area is then considered to belong to the unstructured area.

[0034] According to a preferred embodiment of the invention, the invention relates to an optoelectronic component which has at least the following components or layers

[0035] • an optoelectronically active layer, a contacting layer and / or a cover layer, each of which independently has an outer surface and an inner surface, wherein the optoelectronically active layer, the contacting layer and / or the cover layer (also in the structured state) is at least partially transparent,

[0036] • at least one functional layer which is at least partially arranged or applied on the inner and / or outer surface of the optoelectronically active layer, the contacting layer and / or the cover layer, wherein the outer surface and / or inner surface of the optoelectronically active layer, the contacting layer and / or the cover layer are each formed independently of one another from a structured and an unstructured region, wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (p1), wherein the first interference pixel (10) has a periodic grating of at least three cones or inverse cones, wherein the interference period of the first periodic dot structure is in the range from 50 nm to 50 pm.

[0037] According to a preferred embodiment, the first interference period of the first periodic dot structure is in the range from 100 nm to 1,000 nm. This preferably allows the antireflection properties of the substrate, in particular of the optoelectronically active layer, the contacting layer and / or the cover layer (as defined herein) to be adjusted.

[0038] According to a preferred embodiment, the first interference period of the first periodic dot structure is in the range of 200 nm to 50 pm, with the water contact angle of the outer surface of the cover layer being less than 20° or greater than 150°. This allows the anti-soiling properties as well as the wetting properties of the cover layer (as defined herein) to be adjusted.

[0039] The present invention is based on the finding that the properties, in particular the transmission, of a surface can be positively influenced by applying a structured area and that this can improve the coupling of light into or out of optoelectronic components without the need to apply an additional layer.

[0040] In photovoltaic cells, optimized light coupling directly leads to increased short-circuit current. Since the materials generally do not need to be modified for this purpose, and thus, especially when structuring the outer surface of the cover layer, the layer transitions are not affected, the fill factor of the current-voltage characteristic curve is advantageously not reduced. Since light extraction is also improved accordingly, this also applies to light-emitting components. This makes it possible to address a core problem of photovoltaics and light-emitting components: the compromise between improved transparency and as unchanged as possible, especially not increased, sheet resistance.An optoelectronic component according to the invention with a cover layer having dot structures leads to increased efficiency, since the optical properties are improved due to a higher proportion of electromagnetic waves penetrating the cover layer, without reducing the electrical properties of the optoelectronic component.

[0041] A characteristic feature of this structured cover layer is that the structured area has lattice structures. In this case, cones or inverse cones are arranged periodically relative to one another, at least in some sections. GENERAL ADVANTAGES

[0042] With the aid of a structuring of surfaces and / or interfaces of substrates of optoelectronic components as described herein, the optical properties of the surface or interface or the properties of the surface when wetted with liquids, such as water, or also with regard to small particles can be advantageously influenced in a targeted manner.

[0043] The optical properties are preferably influenced in such a way that a larger proportion of the incident electromagnetic radiation, e.g., visible light, passes through a plane of the substrate, in particular the surface of the substrate, through this plane. Thus, the proportion of electromagnetic radiation passing through this surface can be increased. A possible structuring increases this proportion due to a modified, preferably gradual, refractive index of the substrate, which reduces reflection at the surface. Furthermore, an applied grating leads to diffraction effects and a deflection of the propagation direction of the light, i.e., the electromagnetic waves. This offers significant advantages for photovoltaic components and photovoltaic modules, as it advantageously increases the path traveled by the light within the optoelectronically active layers.This allows a larger proportion of the incident light to be absorbed, creating a larger number of charge carriers, thereby improving the efficiency of the photovoltaic component or module. However, a structure can also be created that increases the proportion of electromagnetic radiation traversing the surface. Multiple reflections within an inverse cone lead to a kind of trapping effect, in which each time the electromagnetic wave strikes a point on the surface, especially within the inverse cone, another portion of the electromagnetic radiation traverses this surface.

[0044] Furthermore, the wetting properties of the surface can be advantageously adjusted to create hydrophilic, superhydrophilic, or even hydrophobic or superhydrophobic properties. This allows anti-fogging effects, i.e., anti-coating and anti-soiling effects, to be generated on the surface of the top layer. Furthermore, the adhesion or sticking properties of the surface can be adjusted by adjusting the surface structuring. In this way, the surface structuring can be specifically designed to reduce the adhesion of solid particles to the surface. In conjunction with the optimized wetting properties, dirt particles are washed off more quickly.

[0045] Furthermore, the structure can be applied / created directly (i.e., without the need to apply the structure indirectly via another layer) to the surface of a cover layer of an optoelectronic component. Since the structuring is not dependent on the refractive index or the adhesion of specific coating materials to the optoelectronic component, this structure is more flexible in its application than conventional chemical structuring or nanostructuring, which requires the application of metal gratings to the arrays.

[0046] Furthermore, the stability of the dot structures created in this way is worth mentioning. They are more durable than conventional coatings because they are applied directly to the surface of a cover layer of an optoelectronic component and / or incorporated into the optoelectronic component. They cannot detach from the surface to be coated over time and due to usage-related material stress, especially mechanical stress. Furthermore, the structures are chemically resistant to solvents and glass cleaners.

[0047] If the structuring is performed in the volume, i.e., inside a substrate of the optoelectronic component, particularly in the transparent, semi-transparent, or translucent cover layer, the resulting structuring (i.e., the dot structure of the structured substrate) is less sensitive to impact and abrasion than conventional coatings. Texturing, i.e., the insertion of a dot structure, inside or within the volume of the material is of interest for applications such as product protection, optical data storage, decoration, etc. Even if structuring inside a component or inside a layer does not improve anti-fogging or anti-soiling properties, the diffraction efficiency can still be increased due to the interaction of light with the structure inside.In this way, an anti-reflection property of a layer, in particular a cover layer and / or a functional layer, can also be achieved.

[0048] In contrast to conventional methods (such as etching, sandblasting, or polymer coatings) for applying or introducing a structure (e.g., roughness) to a substrate, a further advantage of the optoelectronic component with a structured cover layer defined herein, or rather the application method, is that only certain sections / areas of a layer of a cover layer can be structured in a targeted and / or partial manner without great effort. This eliminates the need for the complex fabrication and placement of a mask for application to a surface to be structured, which, for example, shields / protects certain areas of the surface from treatment. Furthermore, the structural parameters (e.g., the interference period, the structure depth, the diameter, the shape, and the size of the inverse cones), and thus also the associated properties, can be adjusted in a targeted and customized manner.

[0049] Further advantageous embodiments and developments emerge from the subclaims and from the description with reference to the figures.

[0050] DETAILED DESCRIPTION OF THE INVENTION

[0051] Effects

[0052] The aim of this invention is to provide structured regions on surfaces and / or in the volume, in particular within a plane in the volume, of optoelectronic components or optoelectronic modules, such as the optoelectronically active layer, the contacting layer and the cover layer, and thereby to adjust the optical effects and / or the wetting effects of these components or modules, in particular their layers.It is understood that the adjustment of the optical effects, in particular the anti-reflection properties, the reduction of reflection due to the trapping effect and light path extension by diffraction at the grating (each as defined herein) as well as the adjustment of the wetting effect by the formation of suitable structured and unstructured regions on the outer surface and / or inner surface and / or in the volume, in particular within a plane in the volume, of a substrate (as defined herein), in particular the functional layer (such as optoelectronically active layer, boundary layer), the contacting layer and the cover layer can each be adjusted independently of one another.Accordingly, the structural parameters, in particular the interference periods, the structural depths, the diameters of the base area of ​​the cones or inverse cones, the proportion of the surface structured in this way or and / or within a plane in the volume of each layer, the degree of disorder within a structured region as well as the periodicity or non-periodicity of the global dot structure on the outer surface and / or inner surface and / or in the volume, in particular within a plane in the volume, of a substrate, in particular the functional layer (such as optoelectronically active layer, boundary layer), the contacting layer and the cover layer, can each be adjusted independently of one another, so that the individual sections herein, even if they are formulated specifically for one layer, can also relate to the other layers of the optoelectronic component or the optoelectronic module.

[0053] Optical effects

[0054] By structuring the cover layer of an optoelectronic component, preferably a photovoltaic cell (also known as a solar cell) or a light-emitting diode (also known as an LED), various effects can be achieved on the cover layer, which can, in particular, improve the efficiency of the optoelectronic components during operation. A key aspect of photovoltaic cell technology is optimizing the coupling of light into the optoelectronically active layer. Since the number of generated charge carriers increases with an increase in the number of coupled-in photons (i.e., light particles), the generated electrical current can be increased by improving the coupling of light into the optoelectronically active layer. In contrast, the efficiency of light-emitting diodes increases with improved light extraction.In any case, an improved passage of electromagnetic radiation, i.e. light through the cover layer of the optoelectronic component, is crucial.

[0055] To achieve this, the proportion of light reflected at the surface or interface is advantageously reduced, allowing a higher proportion to reach the optoelectronically active layer. Two different effects can be utilized for this purpose, which can be achieved through different structuring, i.e., with different interference periods or structure depths.

[0056] On the one hand, the increase in the amount of light passing through the surface or interface is due to a change in the surface's refractive index. This effect is known as anti-reflection. Glass, for example, as an interface to air, has a typical reflection of 4%. This means that up to 4% of the light can be captured at such a surface. On the other hand, the increased penetration of the surface or interface can also be due to the fact that the side surfaces of the cones or inverse cones, due to their orientation, ensure that the incident light hits the surface of the cover layer several times within the cone or inverse cone. Thus, with each impact, an additional portion of the electromagnetic radiation or light reaches the interior of the cover layer or exits it.

[0057] Wetting effects

[0058] An improvement in light input or output can also be achieved by avoiding effects that prevent efficient transmission at the surface or interface. For example, anti-contamination properties of the outer surface of the cover layer can ensure that fewer dirt particles cause impairments. Such wetting effects are based on hydrophilic or superhydrophilic or on hydrophobic or superhydrophobic surfaces. Optimizing the wetting properties primarily plays a role on the surface of the optoelectronic component. For example, on a superhydrophobic surface, the lotus effect occurs upon contact with a liquid, preferably water, and small dirt particles adhere to the liquid droplets moving along the surface and repelled by the surface.

[0059] Superhydrophilic surfaces also exhibit such an effect, with a uniformly distributed liquid film removing the dirt particles.

[0060] Optoelectronic component

[0061] The optoelectronic component generally comprises at least one optoelectronically active layer and at least two contacting layers, which are suitable for conducting the charge carriers into the optoelectronic component, as in a light-emitting diode, or out of the optoelectronic component, as in a photovoltaic cell. An optoelectronic component within the meaning of the invention is a single optoelectronic cell, with an optoelectronic module being formed from a plurality (i.e., at least two) optoelectronic cells. By connecting a plurality of optoelectronic cells in series, the achieved efficiency of the emission and / or absorption of electromagnetic radiation within a module can be improved, in particular increased.

[0062] The optoelectronic component (component for short) can be a radiation-emitting component or a photovoltaic component. The optoelectronic component can be a photovoltaic component, a light-emitting diode (LED), or an organic photodiode (OPD), wherein the optoelectronically active layer is correspondingly formed as a region that can emit and / or absorb electromagnetic radiation, preferably light, during operation. The light can be in the spectral range optically visible to humans or in the range of infrared or ultraviolet radiation, as defined herein. Optoelectronic components that emit electromagnetic radiation, preferably light, can be, for example, light-emitting diodes (LEDs) or organic light-emitting diodes (OLEDs). An optoelectronic component that absorbs electromagnetic radiation can be, for example, a solar cell or a photodiode, e.g.an organic photodiode (OPD) or organic photocell.

[0063] A radiation-emitting component, within the meaning of the invention, is a single radiation-emitting cell, with a radiation-emitting module being formed from a plurality of (i.e., at least two) radiation-emitting cells. By connecting a plurality of radiation-emitting cells in series, the achieved emission of electromagnetic radiation within a module can be improved, in particular increased.

[0064] A photovoltaic component, within the meaning of the invention, is a single photovoltaic cell, with a photovoltaic module being formed from several (i.e., at least two) photovoltaic cells. By connecting several photovoltaic cells in series, the voltage achieved within a module can be improved, in particular increased.

[0065] According to one embodiment of the invention, an optoelectronic component is designed as a layer stack, the layers of which are arranged flatly adjacent to one another in a stacking direction (S), and wherein the layer stack comprises at least three flatly extended layers, in particular a first layer terminating the optoelectronic component (herein also "first terminating layer"), a second layer terminating the optoelectronic component (herein also "second terminating layer"), and a functional layer arranged or applied between the first and the second terminating layer, wherein the functional layer is preferably an optoelectronically active layer or a contacting layer.

[0066] According to a preferred embodiment, the first or the second final layer is formed as a cover layer of the optoelectronic component, wherein, depending on the preceding selection (i.e., whether the first or the second final layer is the cover layer), the other final layer is preferably formed as a carrier layer. In this case, it can be provided that the functional layer is an optoelectronically active layer, wherein, in the stacking direction (S), depending on the preceding selection, a contacting layer can be arranged independently of one another between the cover layer and the optoelectronically active layer, as well as between the optoelectronically active layer and the carrier layer.

[0067] According to a further embodiment, the optoelectronic component can be designed to be rigid or mechanically flexible (so that the optoelectronic component can be unwound or wound non-destructively from a roll). According to a further development, the optoelectronic component is designed to be flexible and / or bendable non-destructively. For example, the optoelectronic component is a flexible organic light-emitting diode (OLED).

[0068] Preferably, the substrate, in particular the optoelectronically active layer, the contacting layer, and / or the cover layer, is flexible, preferably in the form of a film. This allows for good adaptability of the substrate to the optoelectronic component. In optoelectronic components made of flexible materials, such as organic semiconductors, the deformability is thus advantageously retained.

[0069] The object is also achieved by an optoelectronic module comprising at least two optoelectronic components according to the invention that are electrically contacted with one another. Each optoelectronic component can have a separate cover layer. Thus, optoelectronic components according to the invention can be combined to form an optoelectronic module.

[0070] However, it is also possible to achieve the advantages of the invention if at least two optoelectronically active (sub-)layers are arranged on a cover layer, each forming a (separate / independent) optoelectronic component. This can lead to a more efficient manufacturing process.

[0071] Optoelectronically active layer

[0072] The optoelectronic component has at least one functional layer. Within the meaning of the invention, the functional layer is a substrate that has or consists of at least one optoelectronically active layer suitable for generating or detecting electromagnetic radiation or for converting electromagnetic radiation into electrical current. The electromagnetic radiation can be, for example, light in the visible range, UV light, and / or infrared light (each preferably as defined herein).

[0073] An optoelectronically active layer, within the meaning of the invention, is a layer, which can also be formed as a layer stack, consisting of materials or material combinations whose properties allow the conversion of electrical energy into electromagnetic waves or photons, or vice versa. A possible suitable base material is, for example, silicon as an inorganic semiconductor. Organic semiconductors and / or typical materials of thin-film solar cells, such as CdTe, are also possible.

[0074] According to one possible embodiment, the optoelectronically active layer has a layer structure based on heterojunction technology. With heterojunction technology, at least a first optoelectronically active layer and a second optoelectronically active layer are applied adjacent to one another. What is characteristic here is that the energy levels, in particular the band gap, differ. The first optoelectronically active layer and the second optoelectronically active layer can be formed from two different materials, for example GaAs and InGaAs. Another possibility is to use the same material in the layers, which is present in a different crystalline form. Thus, one embodiment of a heterojunction provides for the first optoelectronically active layer to be made of crystalline silicon and the second optoelectronically active layer to be made of amorphous or polycrystalline silicon.Furthermore, additional layers, such as a third optoelectronically active layer, can be arranged within the heterojunction. In this case, two adjacent layers of the heterojunction each have different energy levels. This advantageously allows charge carriers to be generated more efficiently and transported to the external contacts. This can advantageously increase the efficiency of the optoelectronic component.

[0075] According to a particularly advantageous embodiment of the invention, the optoelectronic component has an optoelectronically active layer according to heterojunction technology using silicon, as proposed, for example, in US5648675A. The optoelectronic component preferably has, as the optoelectronically active layer, a first layer formed from a crystalline, doped, preferably n- or p-doped, particularly preferably n-doped, layer. Furthermore, a second layer adjacent to the first layer is provided, which is formed as an amorphous or polycrystalline silicon layer. On the side of the first layer facing away from the second layer, a third layer made of doped and intrinsic, amorphous or polycrystalline silicon is also provided. The second and third layers are preferably thinner than the first layer.

[0076] The optoelectronically active layers of the optoelectronic component can comprise various materials, such as inorganic semiconductor materials, for example, silicon, cadmium telluride (CdTe), or gallium arsenide (GaAs). Other possible materials include organic semiconductor materials, such as organic polymers, conjugated polymers, organic oligomers, organic monomers, organic small, non-polymeric molecules ("small molecules," e.g., fullerenes), or combinations thereof. Perovskites, particularly those with the general formula ABX3, are also considered suitable materials for optoelectronically active layers.

[0077] According to one embodiment, the optoelectronically active layer is part of a sequence of optoelectronically active layers, in particular a semiconductor layer sequence. The sequence of optoelectronically active layers can in particular comprise a plurality of optoelectronically active layers made of organic semiconductor materials and / or inorganic semiconductor materials, for example electron-transport layers, electroluminescent layers, and / or hole-transport layers.

[0078] The optoelectronically active layer can be based on an organic semiconductor material and / or an inorganic semiconductor material. According to one embodiment, the optoelectronically active layer is an inorganic semiconductor material, preferably comprising silicon, CdTe, GaAs, or CIS (CuInS2, copper indium sulfide), CIGS (Cu(In,Ga)(S,Se)2, such as copper indium gallium diselenide or copper indium disulfide).

[0079] The optoelectronically active layer can, for example, be formed as a layer of a semiconductor layer sequence.

[0080] According to a further embodiment, the optoelectronically active layer, preferably the semiconductor layer sequence, comprises an organic semiconductor material. In particular, the semiconductor layer sequence can comprise a sequence of organic, optoelectronically active layers, so that the optoelectronic component is embodied as an organic light-emitting diode (OLED) or an organic photodiode (OPD).

[0081] According to a preferred embodiment of the invention, the optoelectronically active layer comprises a phosphor. The phosphor can, for example, be present in the form of phosphor particles dispersed in a matrix material. Thus, the phosphor can preferably be present in the form of a suspension in the matrix material. This allows for a uniform distribution of the phosphor and thus a uniform excitation of the phosphor and also a uniform light emission. Silicone, epoxy, or a hybrid, for example, are used as the matrix material. Hybrids can be epoxy-silicone or silicone-polyester.

[0082] The phosphor can also be incorporated into a matrix material together with scattering particles. This ensures uniform light emission.

[0083] The optoelectronic component is preferably designed as a light-emitting diode (LED), laser diode, or photovoltaic cell. According to an advantageous embodiment, the photovoltaic cell is a tandem cell. In such a tandem cell, the efficiency is increased by using different optoelectronically active materials because the different materials absorb particularly well in different areas. Good light coupling is particularly important for such optimized photovoltaic cells. This effect can be further enhanced by triple cells, in which three different materials contribute to absorption.

[0084] According to the invention, the optoelectronically active layer has an outer side with an outer surface (also referred to herein as “outer surface”), which in the sense of the invention (when used as intended) represents an interface facing the cover layer or the environment in the stacking direction (S).

[0085] In addition, the optoelectronically active layer has an inner side with an inner surface (also referred to herein as “inner surface”), which in the sense of the invention (when used as intended) represents an interface facing away from the interior of the optoelectronic component, i.e. a boundary surface facing away from the cover layer or the environment in the stacking direction (S), wherein the inner surface of the optoelectronically active layer forms the interface between the optoelectronically active layer and the layer upstream in the stacking direction (S) or another component of the optoelectronic component.

[0086] According to one embodiment of the invention, the outer surface and / or inner surface and / or the volume, in particular within a plane in the volume, in particular the outer surface of the optoelectronically active layer is formed from a structured and an unstructured region (as defined herein), wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi), wherein the first interference pixel (10) has a periodic lattice of at least three cones or inverse cones, wherein the interference period (pi) of the first periodic dot structure is in the micrometer range or submicrometer range (as defined herein).This has the advantage that the optical properties of the optoelectronically active layer are influenced in such a way that a larger proportion of the incident electromagnetic radiation, e.g. visible light, passes through a plane of the optoelectronically active layer, in particular the surface of the optoelectronically active layer, through this plane. The proportion of electromagnetic radiation passing through this surface can thus be increased. A possible structuring increases this proportion due to a changed, preferably gradual, refractive index of the substrate, which, for example, reduces the reflection (as defined herein) at the surface. Furthermore, an applied grating leads to diffraction effects and a deflection of the propagation direction of the electromagnetic radiation, i.e. the electromagnetic waves. This brings, for example,This offers great advantages for photovoltaic components and photovoltaic modules, as it advantageously increases the path traveled by the light within the optoelectronically active layers. This allows a larger proportion of the incident light to be absorbed, resulting in a larger number of charge carriers, thereby improving the efficiency of the photovoltaic component or photovoltaic module. However, it is also possible to create a structure that increases the proportion of electromagnetic radiation traversing the surface. Multiple reflections within an inverse cone lead to a type of trapping effect (as defined herein), whereby each time the electromagnetic wave strikes a point on the surface, particularly within the inverse cone, a further portion of the electromagnetic radiation traverses this surface.

[0087] According to a further embodiment of the invention, the optoelectronic component can also have a boundary layer as a functional layer. In the boundary layer (pn junction) between n- and p-conducting material, the mobile charge carriers cancel each other out, while the stationary charges (negative in the p-conducting and positive in the n-conducting material) are retained. For this reason, the boundary layer is depleted of mobile charge carriers. Due to diffusion, a positively charged zone forms in the n-doped region and a negatively charged zone in the p-doped region. Thus, a space charge zone is formed. The energy of incident photons supplies energy to existing electrons, causing them to become mobile charge carriers that move toward the positively charged zone (an example of an optoelectronically active layer).At the same time, holes are created—positively charged, mobile charge carriers—which in turn move toward the negatively charged zone. Thus, the energy of the incident photons, i.e., the electromagnetic radiation, causes a flow of charge carriers. For the purposes of this invention, the boundary layer is also understood as an optoelectronically active layer or can be a component of one.

[0088] The boundary layer can be formed as a dielectric material, wherein the boundary layer can be electrically conductive, in particular due to tunneling currents. In order to increase the surface area of ​​the boundary layer to the adjacent optoelectronically active layers and thus improve the active area for charge exchange and consequently the charge exchange itself between n- and p-conducting material, it is advisable to form the boundary layer, in particular the inner and / or outer surface, from a structured and an unstructured region, wherein the structured region has a periodic dot structure, in particular a first periodic dot structure, as defined herein.

[0089] In particular, the possibility of creating hierarchical structures (as defined herein) on the surface of the interface by means of laser structure application methods, in particular direct laser interference structuring, offers the advantage that the surface available for charge transfer can be "roughened," for example, starting from the micrometer range down to the submicrometer range. This advantageously forms defined contacts or contact areas where the two surfaces abut one another. In the areas where pegs of one surface are arranged in the inverse pegs of a second surface, defined contact areas are created in these areas.

[0090] Typical materials for such boundary layers, especially so-called hole transport layers, can be MoO x , VO X , WHERE X CuO x and CuSCN or NiO x Contacting layer

[0091] The optoelectronic component preferably has at least one “first contacting layer” and one “second contacting layer” which are suitable for conducting the charge carriers into the optoelectronic component, as in the case of a radiation-emitting component (e.g. a light-emitting diode), or out of the optoelectronic component, as in the case of a photovoltaic cell.

[0092] Preferably, the first contacting layer and the second contacting layer directly delimit (i.e. immediately adjacent to) the functional layers of the optoelectronic component, and thus represent the direct termination to the functional layers, in particular optoelectronically active layers, in the stacking direction (S).

[0093] Preferably, the “first contacting layer” is arranged in the stacking direction (S) in the layer sequence upstream of the functional layers of the optoelectronic component, in particular the optoelectronically active layers, the second contacting layer and optionally a cover layer.

[0094] Preferably, the “second contacting layer” is arranged in the stacking direction (S) in the layer sequence downstream of the first contacting layer and the functional layers of the optoelectronic component, in particular the optoelectronically active layers, and optionally upstream of a cover layer.

[0095] The contacting layers are preferably also functional layers which serve for electronic contacting of the optoelectronically active layer of the optoelectronic component and preferably have a low resistance.

[0096] Optionally, the cover layer can be formed as one of the contacting layers and / or adjoin a contacting layer.

[0097] In the sense of the invention, a contact is always an electrical contact with an electrical conductivity of at least an electrical conductivity of more than 1 S / cm, preferably 10 3 S / cm, particularly preferably 10 4 S / cm. The contact layers preferably have a specific resistance of less than 10 -1 The, preferably less than 10 -2 The, particularly preferably less than 10 -3Preferably, further contacting elements, such as metal wires, which are electrically connected to one of the contacting layers, are arranged on the optoelectronic component. According to one possible embodiment, such contacting elements are designed as contact fingers and / or busbars, wherein the busbars ensure the transport of charge carriers to the outside. An arrangement of thin metal wires is also possible, which represents a good compromise between charge carrier transport and low shading. Preferably, such metal wires are embedded in a film, as in the case of so-called "smart wire" technology, for example, wherein the film comprising the metal wires can be applied to a module comprising a plurality of photovoltaic cells, such that the plurality of photovoltaic cells are then electrically connected by the metal wires.According to an advantageous embodiment, a film comprising such metal wires is the cover layer of an optoelectronic component.

[0098] The contacting elements can be formed independently of one another from a substrate and an intermetallic compound arranged thereon. Suitable substrates in this case are, in particular, substrates consisting largely of copper, steel or an iron alloy. The intermetallic compound preferably comprises at least one metal selected from the group Cu, Sn, Ag, Ni, Fe, Ru, Zr, Au or Al or the intermetallic compound is an alloy or an intermetallic compound with one or at least two of these metals. According to a preferred embodiment of the invention, the intermetallic compound contains tin (Sn) and copper (Cu), is an alloy of tin and copper, or consists essentially of tin and copper.

[0099] The substrate of the contacting elements can have a layer of an intermetallic compound in some regions and surface areas made of a metal or a (metal) alloy different from the intermetallic compound in some regions. The layer of the intermetallic compound can have a thickness of 500 nm to 20 pm, in particular 1 pm to 10 pm.

[0100] To form this layer of the intermetallic compound on the surface of the substrate, a metal layer comprising at least one metal selected from the group consisting of Cu, Sn, Ag, Ni, Fe, Ru, Zr, Au, or Al is preferably applied to the substrate. By means of laser interference structuring, an energy input is generated on the generated surface, thus stimulating the formation of an intermetallic compound, preferably comprising at least one metal or at least two metals selected from the group consisting of Cu, Sn, Ag, Ni, Fe, Ru, Zr, Au, or Al, or comprising an alloy with one or at least two of these metals. This advantageously allows a high conductivity, preferably at least 2 x 10 4 S / cm, particularly preferably at least 3 x 10 4S / cm can be achieved. Good conductivity can thus be achieved here without using a large amount of expensive metals such as Cu, Sn, Ag, Ni, Fe, Ru, Zr, Au or Al. According to a preferred embodiment, the contacting element can have an outer surface and / or inner surface, preferably an outer surface, wherein the outer surface and / or inner surface, preferably an outer surface, is formed from a structured and an unstructured region (each as defined herein), wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel with a first interference period (pi), and wherein the first interference pixel has a periodic lattice of at least three cones or inverse cones.Such structuring has the advantage of achieving a targeted roughening of the outer and / or inner surface of at least one of the contact partners, e.g., the contacting element, in such a way that the effective surface intended for charge exchange or charge transfer between two contact partners, e.g., the contacting element and the contact layer and / or the pickup, is specifically influenced; in particular, defined contacts or contact areas are created. This advantageously reduces the electrical contact resistance and / or increases the conductivity.

[0101] Contact partners can also be an optoelectronically active layer and a boundary layer arranged adjacent to it.

[0102] Particularly preferred are regions on the surface of one substrate that are complementary to regions, in particular to the contact area of ​​the surface of the other, preferably oppositely arranged substrate (the so-called Lego principle). This allows for an enlarged surface area to be created. Furthermore, the individual adjacent layers can advantageously be fixed in place. This is particularly due to the fact that the dot structures allow fewer degrees of freedom with respect to displacement than is the case, for example, with line structures.

[0103] In this way, defined contacts with specific properties that fit together can be formed. In particular, the possibility of creating hierarchical structures (as defined herein) on the surface of the interface using laser structure application methods, especially direct laser interference structuring, offers the advantage that the surface available for charge transfer can be "roughened," for example, starting from the micrometer range down to the submicrometer range. This advantageously creates defined contacts or contact areas where the two surfaces abut each other.Due to the superimposed quasi-periodic line structures (LIPPS) within the inverse pegs of a first surface and / or on the pegs of the adjacent second surface, defined contact areas can also be created in the areas in which pegs of the second surface are arranged in the inverse pegs of the first surface.

[0104] In one embodiment, the contacting layer, in particular the second contacting layer, is formed as a layer permeable to radiation generated in an optoelectronically active layer or to externally incident radiation. Particularly preferably, the contacting layer contains a transparent conductive oxide (TCO). Transparent conductive oxides are transparent, conductive materials, typically metal oxides, such as zinc oxide, tin oxide, cadmium oxide, titanium oxide, indium oxide, or indium tin oxide (ITO). In addition to binary metal-oxygen compounds, such as ZnO, ZnO:Al, SnO2, or In2O3, the group of TCOs also includes ternary metal-oxygen compounds, such as Zn2SnO4, CdSnO3, ZnSnO3, MgIn2O4, GaInO3, Zn2In2O5, or In4Sn3O2, or mixtures of different transparent conductive oxides.Furthermore, the TCOs do not necessarily correspond to a stoichiometric composition and can also be p-doped or n-doped. Such a contact layer has the advantage that it can be transparent or semi-transparent, i.e., transparent, for radiation generated in or incident on the optoelectronically active layer.

[0105] According to the invention, the second contacting layer has an outer side with an outer surface (also referred to herein as “outer surface”), which in the sense of the invention (when used as intended) represents an interface facing the cover layer or the environment but facing away from the optoelectronically active layer of an optoelectronic component.

[0106] In addition, the second contacting layer has an inner side with an inner surface (also referred to herein as “inner surface”), which in the sense of the invention (when used as intended) represents a side / surface facing the interior of the optoelectronic component, i.e. the active region of the optoelectronic component, wherein the surface of the inner side of the second contacting layer forms the interface between the second contacting layer and the preceding layer (e.g. an optoelectronically active layer, as it is arranged upstream in the stacking direction (S)) or another component of the optoelectronic component.

[0107] According to one embodiment of the invention, the outer surface and / or inner surface and / or the volume, in particular a plane within the volume, of the contacting layer is formed from a structured and an unstructured region (as defined herein), wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi), wherein the first interference pixel (10) has a periodic lattice of at least three cones or inverse cones, wherein the interference period (pi) of the first periodic dot structure is in the micrometer range or submicrometer range (as defined herein). This has the advantage that the optical properties of the contacting layer, in particular of the second contacting layer, are influenced in such a way that a larger proportion of the incident electromagnetic radiation, e.g.of visible light at a plane of the contacting layer, in particular the surface of the contacting layer, passes through this plane. Thus, the proportion of electromagnetic radiation traversing this surface can be increased. A possible structuring increases this proportion due to a changed, preferably gradual, refractive index of the substrate, which, for example, reduces the reflection (as defined herein) at the surface. Furthermore, an applied grating leads to diffraction effects and a deflection of the propagation direction of the electromagnetic radiation, i.e., the electromagnetic waves. This brings great advantages, for example, for photovoltaic components and photovoltaic modules, since the path that the light travels within the optoelectronically active layers is advantageously increased.Thus, a larger proportion of the incident light can be absorbed, creating a larger number of charge carriers, thereby improving the efficiency of the photovoltaic component or photovoltaic module. However, a structure can also be created that increases the proportion of electromagnetic radiation traversing the surface by multiple reflections within an inverse cone, resulting in a type of trapping effect (as defined herein), in which each time the electromagnetic wave strikes a point on the surface, especially within the inverse cone, another portion of the electromagnetic radiation traverses this surface. Cover layer.

[0108] For the purposes of the invention, a “cover layer” is a substrate, in particular a partially transparent substrate, which does not constitute an optoelectronically active layer within the meaning of the invention and is preferably designed to seal off the optoelectronic component from the environment. The cover layer delimits the optoelectronic component, in particular the functional layers of the optoelectronic component, in at least one spatial direction, preferably in the stacking direction (S), i.e. in the spatial direction in which the individual layers are applied to one another, and in this spatial direction represents the seal to the functional layers, preferably directly from the environment. Depending on the use of the optoelectronic component, the cover layer is designed for the incidence of light into and / or for the exit of light from the optoelectronic component.For example, the cap layer in a solar cell is the layer that separates the solar cell from the surroundings / environment, the layer through which light entering the solar cell from the outside passes first. In contrast, the cap layer in a light-emitting diode (LED) is preferably the layer that separates the light-emitting diode from the surroundings / environment, the layer through which the generated light emerging through and from the light-emitting diode passes last, as seen from the inside of the light-emitting diode.

[0109] According to the invention, the cover layer has an outer side with an outer surface (also referred to herein as "outer surface"), which within the meaning of the invention (when used as intended) represents a side that closes off from the surroundings or the environment surrounding the optoelectronic component, wherein the outer surface of the outer side of the cover layer defines the interface between the cover layer and the environment. For example, the environment surrounding the optoelectronic component is air. However, it can also be provided that the environment surrounding the optoelectronic component is also formed as a further layer, such as a carrier layer, for example when the optoelectronic component is arranged within a complex device, such as an optoelectronic module, preferably a solar cell module.In this case, the further layer adjacent to the cover layer can be one or more encapsulation layers.

[0110] In a photovoltaic cell, the cover layer preferably forms the final layer through which the electromagnetic radiation penetrates into the component. The cover layer has an inner side with an inner surface (also referred to herein as the "inner surface"), which in the sense of the invention (when used as intended) represents a side / surface facing the interior of the optoelectronic component, i.e., the active region of the optoelectronic component, wherein the surface of the inner side of the cover layer forms the interface between the cover layer and the next layer (e.g., a contact layer, an optoelectronically active layer, as these follow in the stacking direction (S)) or another component of the optoelectronic component.

[0111] The cover layer can also be the carrier layer on which the other functional layers are applied. Optionally, the cover layer is a layer suitable as a contact layer for a photovoltaic cell, the resistance of which is at least sufficiently low to allow the resulting charge carriers to be effectively transported to the existing contact fingers. Furthermore, a cover layer suitable as a contact layer in a light-emitting diode can contribute to the transport of charge carriers to the optoelectronically active materials, i.e., in which the conversion of electrical energy occurs through the emission of photons or electromagnetic waves.

[0112] One possible embodiment provides that both the inner and outer surfaces of the cover layer are formed from a structured and an unstructured region. One possible configuration provides that the first periodic dot structure has inverse pegs on both the inner and outer surfaces. Advantageously, both the inner and outer surfaces can thus be structured directly using a laser, preferably using a laser interference method, thereby directly generating the advantageous properties of the surfaces, in particular the anti-reflection properties.

[0113] According to an alternative embodiment, the first periodic dot structure has pegs on both the inner and outer surfaces. Advantageously, both the inner and outer surfaces can thus be structured using a negative mold having inverse pegs. This allows the advantageous properties of the surfaces, in particular the anti-reflection properties, to be generated efficiently in rapid processes. For example, a roll-to-roll process for processing cover layers in the form of films is possible. A third possibility provides for the first periodic dot structure to have pegs on the inner surface and the first periodic dot structure to have inverse pegs on the outer surface. This advantageously reduces reflection due to the trapping effect on both the inner and outer surfaces.This reduction in reflection due to the trapping effect can be achieved for external light coupling, i.e., when the light first hits the outer surface, then passes through the cover layer, and then enters the adjacent layers through the inner surface. This variant is therefore particularly suitable for photovoltaic components or photovoltaic modules.

[0114] According to another possible variant, the first periodic dot structure on the inner surface has inverse cones and the first periodic dot structure on the outer surface has cones. This can advantageously reduce reflection due to the trapping effect on both the inner and outer surfaces. This reduction in reflection due to the trapping effect can be achieved for light extraction from the inside to the outside, i.e. when the light first hits the inner surface of the cover layer, then traverses the cover layer and finally exits the cover layer through the outer surface. This variant is therefore particularly suitable for light-emitting components or modules in which light, i.e. electromagnetic radiation, is generated within the functional layers.

[0115] According to an advantageous embodiment, the cover layer is designed as an optical element or spectral filter element. The optical element can be, for example, a spherical or aspherically shaped lens. Embodiments are also conceivable in which the optical element is a stepped lens or a scattering plate. Embodiments are also conceivable in which the optical element is a stepped lens or a scattering plate. The spectral filter element is designed to minimize or completely eliminate the intensity of unwanted spectral components, e.g. parasitic luminescence ("defect luminescence"). An example of a spectral filter element is an optical shortpass filter or, alternatively, a bandpass filter with a corresponding lower band edge, which is arranged in the packaging (herein also as encapsulation) or directly in or on an optoelectronic component.The spectral filter element is particularly preferably a Bragg reflector (also called a Bragg mirror). The Bragg reflector preferably consists of alternating, thin layers of different refractive indices, which usually consist of dielectrics, with a portion of the electromagnetic wave of the light being reflected at each boundary layer according to Fresnel's formulas. A spectral filter element, in particular a Bragg reflector, can be a layer stack applied to a substrate. A spectral filter element integrated into the packaging, in particular a Bragg reflector, can be applied to a cover layer as an additional layer of the cover layer. The surface and / or the volume, in particular a plane within the volume, of the optical element or spectral filter element can be smooth or structured depending on the function of the element. This advantageously allows the light coupling or light extraction to be further optimized.This further improves the efficiency of the optoelectronic component. Such an element is preferably arranged on a light-emitting optoelectronic component, such as an LED or a laser diode. This allows the properties of the emitted light to be specifically influenced and adapted to the specific application.

[0116] The structuring of the outer surface and / or inner surface and / or the volume, in particular of a plane in the volume, of an optical element or spectral filter element with a structured and an unstructured region (as described herein) allows, for example, the coupling of light into or out of optoelectronic components to be improved. Thus, it can be provided that a spectral filter element that is arranged in a radiation-emitting component and is intended for the (back) reflection of certain spectral ranges, e.g. in the UV range, into the radiation-emitting component, on its inner surface (iethe side facing the optoelectronic component) is formed from a structured and an unstructured region, which allows improved light coupling, in particular by achieving anti-reflection properties and / or reduced reflection due to the trapping effect with structural parameters (each as defined herein) into the spectral filter element.

[0117] Such a cover layer configured as an optical element or spectral filter element preferably has an average structural depth d5o of a maximum of 2 pm, particularly preferably a maximum of 1 pm. Advantageously, the properties of the optical element, such as transparency and the influence on the propagation direction of light or a light beam, are thus hardly changed. Thus, the function of the optical element is retained, even if it has an outer surface and / or an inner surface with structured and unstructured regions.If the inverse cones or cones of the dot structure are additionally formed with side surfaces that form a smooth surface, this effect of maintaining the properties of the optical element is further enhanced and the difference, in particular in the transparency, between an optical element with at least one structured surface and an optical element whose surfaces have only unstructured areas, hardly differ, preferably by no more than 10%, preferably 5%.

[0118] Another option is to form the cover layer from glass or materials that contain gas. This choice of material results in high transparency combined with stable behavior. The glass can be selected from the group consisting of mineral glass, quartz glass, sapphire glass (Al2O3), aluminosilicate glass, zirconia (ZrO2), glass-ceramic systems (composite materials made of glass and crystals), such as the MAS system (MgO x Al2O3 x nSiO2 system), the ZAS system (ZnO x Al2O3 x nSiO2 system), the LAS system (l_i2O x Al2O3 x nSiO2 system), and mixtures thereof.

[0119] Optionally, the cover layer is designed as a contacting layer, wherein several cover layers according to the invention can also be arranged on an optoelectronic component, which are separated from one another, for example, by metal wires.

[0120] According to a preferred embodiment of the invention, the cover layer is formed as a single-layer or multi-layer cover layer that extends over the optoelectronic module and thus preferably over at least two optoelectronic components. According to one embodiment, an optoelectronic module has a plurality of cover layers, each of which extends over at least two optoelectronic components. The plurality of cover layers preferably extend over different optoelectronic components.

[0121] According to one embodiment of the invention, the cover layer may comprise a “first cover layer” and a “second cover layer”, wherein

[0122] - the "first cover layer" is arranged downstream of the functional layers in the stacking direction (S) and upstream of the second cover layer and preferably directly (i.e. immediately adjacent to the functional layers) delimits the functional layers of the optoelectronic component and thus represents the direct termination to the functional layers in the stacking direction (S), and the "second cover layer" is arranged downstream of the functional layers and the first cover layer in the stacking direction (S) and preferably represents the direct termination of the individual upstream layers of the optoelectronic component in the stacking direction with respect to the environment.

[0123] Both the first cover layer and the second cover layer have an outer surface and an inner surface. Thus, it can be provided that the outer surface and / or the inner surface of the first cover layer and / or the outer surface and / or the inner surface of the second cover layer are formed from a structured and an unstructured region (as defined herein).

[0124] According to a preferred embodiment of the invention, the outer surface and / or the inner surface of the first cover layer is formed from a structured and an unstructured area.

[0125] According to a preferred embodiment of the invention, the outer surface and / or the inner surface of the second cover layer is formed from a structured and an unstructured region. With the aid of a structuring of the outer surface and / or the inner surface of the second cover layer as described herein, the optical properties of the surface or interface or the properties of the surface when wetted with liquids, such as water, or with regard to small particles, can advantageously be specifically influenced. For example, the outer surface of the second cover layer can be formed from a structured and an unstructured region, in particular for the formation of anti-reflection properties and / or anti-soiling properties (as defined herein).

[0126] According to a preferred embodiment of the invention, at least the inner surface of the first cover layer and the outer surface of the second cover layer are formed from a structured and an unstructured region (as defined herein). In this case, it is advisable for the inner surface of the first cover layer to be structured before application to the layer stack, or for it to be formed from a structured and an unstructured region. The structured region can be applied to the outer surface of the second cover layer after application of the second cover layer to the layer stack, or the outer surface of the second cover layer is already structured before application to the layer stack.

[0127] It can be provided that the second cover layer is formed as a single-layer or multi-layer encapsulation of the optoelectronic component or the optoelectronic module, which protects the functional layers of the optoelectronic component or the optoelectronic module, comprising a plurality of optoelectronic components, from environmental influences such as moisture. Preferably, a cover layer formed as an encapsulation layer delimits the optoelectronic component or module from the surrounding air. In this case, it is advantageous for the outer surface and / or the inner surface, in particular the outer surface, of the second cover layer to be formed from a structured and an unstructured region, in particular for the formation of anti-reflection properties and / or anti-dirt properties (as defined herein).

[0128] According to a preferred embodiment of the invention, the second cover layer is formed as a single-layer or multi-layer encapsulation as the final layer of a single optoelectronic component (so-called single-cell encapsulation). In this case, the first cover layer can be formed as a contacting layer.

[0129] According to a preferred embodiment of the invention, the second cover layer is formed as a single-layer or multi-layer encapsulation as a final layer of the optoelectronic module (as defined herein) as an arrangement of at least two optoelectronic components.

[0130] The second cover layer can, for example, be formed as a multilayer encapsulation comprising a layer sequence that includes at least one barrier layer and at least one planarization layer. Either a barrier layer or a planarization layer can be arranged on the outer side of the encapsulation. The outer side of the encapsulation is the side of the encapsulation facing away from an element to be encapsulated.

[0131] Preferably, the second cover layer, which is formed as a single-layer or multi-layer encapsulation, has a low water permeability and / or gas permeability, in particular oxygen permeability, which is particularly advantageous for the encapsulation of organic light-emitting diodes (OLEDs), since this reliably protects the organic layers of an OLED from water and oxygen degradation.

[0132] According to one embodiment, the barrier layer may contain a metal oxide. The metal oxide may be selected from a group comprising aluminum oxide, zirconium oxide, hafnium oxide, tantalum oxide, zinc oxide, lanthanum oxide, titanium oxide, and combinations thereof. The barrier layer may comprise at least two sublayers, each sublayer comprising a metal oxide.

[0133] For the second cover layer, which is preferably designed as a single-layer or multi-layer encapsulation, the thickness can be selected in the range from 50 nm to 1.5 pm inclusive, particularly preferably in the range between 50 nm to 1.0 pm inclusive, in particular including 100 nm to 500 nm, very particularly preferably in the range from 200 nm to 300 nm.

[0134] In a preferred embodiment, a protective layer can be formed on the optoelectronic component. In particular, the protective layer is formed as a (partial) layer of the second cover layer, which can preferably be formed as a single-layer or multi-layer encapsulation. According to a further development, to form the protective layer, a starting material can be applied to the existing layers of the encapsulation, which is then cured, for example. The starting material can, for example, comprise or be an adhesive, synthetic resin, acrylic and / or epoxy and / or be curable using UV light. The selective curing of the first section can, for example, be carried out by arranging a mask over the starting material and irradiating sections of the protective layer exposed in the mask.Subsequent destruction of the remaining UV activator substances may occur, so that the cross-linking of the material differs locally from one or more neighboring sections.

[0135] Substrat

[0136] For the purposes of the invention, the term substrate refers to a material or a material composition from which the layers of the optoelectronic component, in particular the optoelectronically active layer, the contacting layer and / or the cover layer, are formed and whose surface extends in multiple spatial directions. A substrate, preferably a flat and / or transparent substrate, can be a planar substrate or a curved substrate, for example a parabolic substrate. For the purposes of the invention, “flat” is further understood to mean that the extension of a substrate, preferably a flat and / or transparent substrate, for example a planar substrate in the x and y directions, or the extension of a curved substrate along its radius of curvature, is greater than the extension of the region in which the at least three partial beams interfere with one another.In a preferred embodiment, the substrate is a substrate whose extension in the x and y directions, or whose extension along a radius of curvature, is less than or equal to the extension of the region in which the at least three partial beams interfere with each other. Homogeneous structuring of the substrate is possible in one processing step (during a laser pulse).

[0137] In a particularly preferred embodiment, the substrate is a flat substrate whose extent in the x and y directions, or whose extent along a radius of curvature, is greater than the extent of the region in which the at least three partial beams interfere with each other. By moving the substrate in the x and y planes, a flat, homogeneous structuring of the substrate is possible in several processing steps (with several laser pulses). The movement of the substrate can be achieved by rotation or translation.

[0138] For the purposes of the invention, the term substrate encompasses a solid material that is transparent or semi-transparent (translucent), for example with a reflective surface. Examples of such materials are polymers, ceramics, epoxies, and glasses. According to a preferred embodiment of the invention, the substrate reflects electromagnetic radiation in the wavelength range from 100 nm to 10 m, for example visible light in the wavelength range from 380 nm to 780 nm, infrared radiation in the wavelength range from 780 nm to 50 pm, or microwave radiation, in particular radar beams in the wavelength range from 1 mm to 10 m. The structuring of the substrate defined herein allows a targeted influencing of the optical properties of the substrate, such as the creation of anti-reflection properties.

[0139] With regard to the substrates that can be processed by applying the method according to the invention, in particular by means of laser interference structuring with a dot structure defined herein, in particular with anti-reflective properties, anti-soiling properties, and / or with a trap effect, a wide selection of transparent or translucent materials is available within the scope of the present invention. Such suitable materials or material compositions that can be used in optoelectronic components are known to those skilled in the art and are described herein by way of example.

[0140] The substrate is preferably a flat and / or transparent substrate. The substrate can be designed as a flexible and / or bendable substrate, such as a polymer film, which is also suitable as a carrier material.

[0141] transparency

[0142] The substrate, for example the cover layer, is preferably made of a transparent material. A material or substrate is transparent within the meaning of the present invention if it has a high transmittance for at least a partial range of the spectrum of electromagnetic radiation between 1 nm and 10 nm, preferably for light that is visible to the human eye or light in the infrared or ultraviolet radiation range. Such partial ranges are, for example, electromagnetic radiation in the range of ultraviolet (UV) light from 100 nm to 380 nm, in particular UV-A from 315 nm to 380 nm or UV-B from 280 nm to 315 nm or UV-C from 100 nm to 280 nm, visible light from 380 nm to 780 nm or in a range that also includes infrared light, from 780 nm to 5.000 nm or in a range of infrared light (heat radiation) or in a range of microwave radiation, in particular radar beams in the wavelength range from 1 mm to 10 m, or else another sub-range which is adapted according to the desired application, in particular to the wavelength of the laser source. Such a sub-range preferably has a width of at least 10% or 50% of the wavelength which forms the lower limit of the sub-range. A high permeability in a sub-range within the meaning of the invention is a transmittance of at least 50% or preferably at least 70% or particularly preferably at least 80% or at least 90% for each wavelength in the sub-range, i.e. for the entire spectrum in the sub-range.In contrast, a substrate is referred to as partially transparent if it has at least a certain degree of transmission, preferably at least 20% for each wavelength in the sub-range, i.e. for the entire spectrum in a sub-range described herein.

[0143] Preferably, the substrate, in particular the optoelectronically active layer, the contacting layer and / or the cover layer, particularly preferably the contacting layer and / or the cover layer, very particularly preferably the cover layer, is transparent, i.e., in a sub-range of the electromagnetic spectrum, preferably in the range of visible light or near-infrared light or the UV range, in particular UV-A and / or UV-B and / or UV-C, it has a transmittance of at least 50%, preferably at least 70%, particularly preferably at least 80%, or at least 90% for each wavelength in the sub-range. However, a substrate which has a high transmittance selectively for certain wavelength ranges in the range of visible light can also be referred to as a transparent substrate; for example, the substrate has a high transmittance for electromagnetic radiation with wavelengths in the range from 500 nm to 800 nm.The transmittance can vary across the transmitted wavelength range, e.g., it can be no less than 70% for wavelengths in the range from 380 nm to 500 nm, and no less than 90% for the range from 500 nm to 750 nm. For example, the substrate transmits radiation with wavelengths from 380 nm to 780 nm. It exhibits particularly high transmittance, e.g., a transmittance of 90%, at wavelengths from 450 nm to 690 nm; the transmittance at wavelengths below and above this range is, for example, 70%.

[0144] It is understood that the transparent substrate, the outer surface and / or inner surface and / or the volume, in particular a plane in the volume, is formed from a structured and an unstructured region, thus remains transparent or at least partially transparent after its structuring (ie after application of a first, second and / or further dot structure, as defined herein), in particular retains its transparent properties.

[0145] A transparent material, for the purposes of the present invention, includes transparent materials, in particular glass, such as borosilicate glasses, quartz glasses, alkali-alkaline earth silicate glasses (e.g., soda-lime glass), aluminosilicate glasses, and metallic glasses. However, a transparent material can also include solid polymers, such as polycarbonates such as Makrolon® and Apec®; polycarbonate blends such as Makroblend® and Bayblen®; polymethyl methacrylate such as Plexiglas®; polyester; polyethylene terephthalate, polypropylene, polyethylene; and transparent ceramics such as spinel ceramics such as Mg-Al spinel, ALON, aluminum oxide, yttrium aluminum garnet, yttrium oxide, or zirconium oxide, or mixtures thereof. Polycarbonates include homopolycarbonates, copolycarbonates, and thermoplastic polyestercarbonates.

[0146] According to a particularly preferred embodiment, the transparent material consists of a glass (as defined herein) or a solid polymer (as defined herein). The silicate framework of glass preferably provides a transmission window for wavelengths in the range between 170 nm and 5,000 nm, i.e. wavelength range which includes visible light in the range from 380 nm to 780 nm and comprises infrared radiation. The structures according to the invention can advantageously be applied to transparent or at least partially transparent substrates, in particular to cover layers or to contacting layers or to optoelectronically active layers. The difficulty here lies in the fact that transparent or partially transparent substrates generally do not absorb, or at least absorb very little, in the wavelength range of laser light.This challenge is particularly evident with glass or a solid polymer, but also with other transparent or semi-transparent substrates.

[0147] It is therefore a major challenge to create a precise, and especially reliably reproducible, material change on the surface or in the volume of the substrate. To ensure energy input into the substrate, it is expedient to exploit nonlinear optical effects, such as frequency doubling. Therefore, the substrates according to the invention are produced with high energy input at very short laser pulse durations (each in particular as defined herein).

[0148] Precise focusing on transparent or semi-transparent substrates is a further challenge. According to an advantageous embodiment, this is solved by a beam splitter element that is designed to be movable along the optical path of the excitation laser, thus allowing the interference period to be adjusted, while the remaining optical elements remain fixed.

[0149] Alternatively, the substrate may also comprise an opaque material.

[0150] For example, such a structured substrate is suitable as a negative mold for the indirect application or creation of structures on another, preferably transparent or translucent, substrate.

[0151] Point-like structure / interference pattern

[0152] The term “inverse peg” in the context of this invention refers to structures with a circular, elliptical, polygonal, such as octagonal, hexagonal, pentagonal, triangular or substantially rectangular base area (relative to the surface of the substrate), in particular with a circular or elliptical base area, which taper conically or pyramidally in the vertical direction to the surface of the substrate, in particular conically into the substrate and have a rounded cone tip or a truncated cone, in particular a rounded cone tip, at their saddle point. The structuring of the surface of a substrate is preferably carried out with inverse pegs, ieapplying the structured regions comprising a first, second, third and / or further interference pixel, in particular on the optoelectronically active layer, the contacting layer and / or the cover layer by a mechanical method, laser structure application method and / or by means of chemical (post-)treatment.

[0153] In a preferred embodiment, the inverse cones are preferably generated during the structuring process by means of laser structure application methods, in particular direct laser interference structuring, i.e., they are formed upon impact of a laser pulse as a result of the impact of a high-intensity region on the substrate to be structured, wherein the regions between the inverse cones on or within the substrate ideally remain essentially unstructured due to destructive interference whose intensity is zero. Consequently, by focusing the laser (partial) beams on or within the substrate, the negative of what determines the intensity distribution is formed. The described shape of the inverse cones refers to point structures arranged on the surface of the substrate.An arrangement of the dot structures in or along a plane within the volume results in a more symmetrical shape, i.e., more like an ellipsoid. For the purposes of the invention, the dot structures generated within a volume by laser interference structuring are also referred to as inverse cones.

[0154] Inverse cones with an elliptical base surface can be created in a structuring process using laser structure application methods, for example by inclining the substrate in relation to the angle of incidence of the focused laser beam(s).

[0155] For the purposes of this invention, "pins" refer to structures with a circular, elliptical, triangular, or substantially rectangular base, in particular with a circular base, which protrude conically from the substrate in the vertical direction and have a rounded cone tip or a truncated cone, in particular a rounded cone tip, at their saddle point. Pins can be applied to or embedded in a surface by applying a negative mold having inverse pins. Imprint lithography, e.g., nanoimprint lithography (as defined herein), is suitable for this purpose.

[0156] The periodic dot structures defined herein, which are preferably formed from cones and / or inverse cones (according to the orientation relative to the surface of a layer in the optoelectronic component), have the advantage over (periodic) line or wave structures that the individual depressions or elevations span a lateral surface that preferably extends radially across the cone cross-section (diameter of the base surface of the cone or inverse cone) to the saddle point. This enables the optical effects defined herein, such as the antireflection properties, the light path extension due to diffraction at the grating, the reduced reflection due to the trapping effect, and wetting effects, to be adjusted independently of the spatial orientation of the respective layer of the optoelectronic component and the angle of incidence of the electromagnetic radiation.For example, electromagnetic radiation, especially light in a photovoltaic cell, can be coupled into the photovoltaic cell or its individual layers more effectively thanks to the periodic dot structures, regardless of the orientation of the photovoltaic cell relative to the angle of incidence of the electromagnetic radiation. This eliminates the need for complex alignment of the photovoltaic cell or the individual layers within it according to the angle of incidence of the electromagnetic radiation.

[0157] According to a preferred embodiment of the invention, for adjacent layers whose surfaces are formed from a structured and an unstructured region, the interface is structured such that one of the two adjacent layers has inverse pegs, whereas the adjacent layer has pegs. Preferably, the pegs of one layer are complementary to the inverse pegs of the adjacent layer, particularly preferably complementary to the inverse pegs of the adjacent layer such that each peg of one surface is arranged in an inverse peg of the other surface (the so-called "Lego principle").Such a complementarily arranged layer stack of at least two layers also has the advantage that the adjacent layers interlock, resulting in interlocking of the layers and thus increased stability of the layer structure. Unlike (periodically arranged) linear or wave structures, this has the significant advantage that the layers cannot be displaced relative to one another in a spatial direction and / or are not connected to one another over long distances, in particular across the width / length of a layer, by a single bridge formed by the linear or wave structure.

[0158] According to a preferred embodiment of the invention, for adjacent layers whose surfaces are formed from a structured and an unstructured region, it is provided that, with respect to the direction of incidence of electromagnetic radiation, preferably light, on the interface between the two layers, the layer from which the electromagnetic radiation emerges and passes into the adjacent layer has a structured region formed from cones (as defined herein). In contrast, the structured region of the layer adjacent to this layer, into which the light enters, is formed from inverse cones. If, for example, within a photovoltaic cell an optoelectronically active layer is arranged adjacent to a contacting layer, the interface between the two layers preferably has cones orinverse pegs, wherein the inverse pegs are formed in the outer surface of the optoelectronically active layer, wherein complementarily thereto the inner surface of the contacting layer has a structured region formed from pegs.

[0159] The period of the structure is defined in the sense of the invention as the interference period (p n ). It generally depends on the structuring of a mask, the negative of the desired periodic dot structure on a mold or the wavelength of the interfering laser beams, the angle of incidence of the interfering laser beams and the number of interfering laser beams.

[0160] The term “interference pixel”, for example first, second, third and / or further interference pixel, refers in the sense of the present invention to a periodic pattern or grid of at least three cones or inverse cones, preferably of at least seven cones or inverse cones, very particularly preferably at least 19 cones or inverse cones on the surface of a substrate, which are formed within an interference pixel (cf. Fig. 15). An interference pixel is preferably characterized in that the cones or inverse cones are repetitively aligned with one another in such a way that, when there are three cones or inverse cones, they are aligned with one another in such a way that their vertices (in the case of cones, their height centers or, in the case of inverse cones, their centers of the depressions) are at the same distance from one another (so-called interference period). When there are seven cones orIn the case of inverse cones, these are aligned with one another in such a way that one cone or inverse cone is arranged centrally in the grid, whereas the six remaining cones or inverse cones are arranged around the center in such a way that each of the vertices (in the case of cones, their height centers or, in the case of inverse cones, the centers of the depressions) of the six remaining cones or inverse cones is at the same distance from the cone or inverse cone in the center and from at least two other of its neighboring cones or inverse cones (so-called interference period). Preferably, the periodic pattern or grid of the interference pixel, in particular comprising inverse cones, is produced by mechanical methods, laser structure application methods and / or by means of chemical (post-)treatment, in particular by direct laser interference structuring. In the case of direct laser interference structuring, the periodic pattern orGrating, in particular the first periodic point structure, preferably also a superimposed point or line structure or all superimposed point and / or line structures, preferably by superimposing at least three, particularly preferably at least four laser (partial) beams as a result of focusing (bundling) these laser (partial) beams onto the surface or into the interior of the substrate, whereby the partial beams interfere constructively and destructively on the surface or in the interior of the substrate.

[0161] The use of laser structure application methods, in particular direct laser interference structuring for the direct production or indirect production (e.g. in the case of imprint lithography, in particular nanoimprint lithography) for producing structured and unstructured regions on the surface of a substrate has the advantage that the cones or inverse cones of a periodic dot structure within a type of interference pixel have identical or almost identical dimensions. Preferably, the coefficient of variation, i.e. the value resulting from the quotient of the standard deviation and the average value, of the cone cross-section (diameter of the base area of ​​the cone or inverse cone) is max. 15.0% or less, more preferably max. 10.0% or less, even more preferably max. 5.0% or less, in particular max. 2.5% or less, even more preferably max. 1.0% or less.This allows for the production of studs or inverse studs that are virtually identical in shape. This also allows for better detection of the substrate structured according to the invention compared to conventional methods for structuring / coating substrates (e.g., etching, particle blasting, polymer coating).

[0162] The point structures thus generated within an interference pixel are designed in the form of periodically arranged cones or inverse cones, wherein, in order to generate a structure on a surface of the substrate, the interference period, i.e. the distance between the vertices of two adjacent cones or inverse cones - i.e. their height centers or centers of the depressions, based on cones formed by an interference pixel, is on average in the range from 1 pm to 50 pm, preferably in the range from 5 pm to 50 pm, more preferably in the range from 10 pm to 30 pm.In a preferred embodiment, by moving the substrate in relation to the focusing point which generates the interference pixel, in combination with pulsed laser (partial) beams, a planar, optionally homogeneous and periodic, dot structure can be generated on the surface or in the interior of a substrate, preferably a planar and / or transparent substrate.

[0163] As an alternative to moving the substrate relative to the focus point, the focus point can also be moved over the sample or substrate (e.g. using scanner-based methods).

[0164] Displacing the substrate to be structured, preferably a flat and / or transparent substrate, in the laser beam can be comparatively complex and slow due to the relatively large masses moved. It is therefore advantageous to keep the substrate, preferably a flat and / or transparent substrate, stationary during processing and to achieve the flat structuring of the substrate by focusing the partial beams on the surface or volume of the substrate by manipulating the partial laser beams with optical elements (focusing mirrors or galvo mirrors (laser scanners)) in the beam direction. Since the masses moved are relatively small, this can be achieved with far less effort and much more quickly. The substrate is preferably arranged in a stationary manner during the process.It is also possible to switch between moving the substrate and guiding the focus point over the substrate, which allows large substrates, for example over 200 mm x 200 mm, to be structured efficiently yet in a defined and reproducible manner.

[0165] Advantageously, the individual pixels of one type of interference pixel, e.g., a first interference pixel, a second interference pixel, and / or a further interference pixel, which are arranged adjacent and repetitively offset from one another, can optionally form a periodic or a non-periodic global dot structure globally (i.e., over the extent of the plane / surface to be structured), which thus forms the structured area. A periodic global dot structure is either a fully periodic global dot structure or a quasi-periodic global dot structure. A fully periodic global dot structure is generated or exists when the preceding pixel and the following pixel of one type of interference pixel are each offset by a whole multiple (e.g., 2, 3, 4, 5) of the interference period (p n) are shifted from each other in one spatial direction. This results in a fully periodic pattern over the extent of the plane to be structured, the period of which corresponds to the interference period (p n ). A quasi-periodic global dot structure is created or exists when the preceding pixel and the following pixel of a type of interference pixel are each spaced apart by an equal multiple (e.g. 0.5; 1.3; 2.6) of the interference period (p n ) are shifted relative to one another in a spatial direction. In contrast, a non-periodic global dot structure is created or exists when the interference period of the subsequent pixel is varied relative to the adjacent, preceding pixel and / or when adjacent, repetitively offset pixels are rotated, e.g., applied in a successively rotated manner.

[0166] According to a preferred embodiment of the present invention, the global dot structure formed by adjacent, repetitively offset pixels of a type of interference pixel is a fully periodic global dot structure or a quasi-periodic global dot structure (each as defined above).

[0167] The inventors of the present invention have further discovered that in addition to the periodicity, the structure depth (i.e., the depth of the inverse cones, measured from their saddle point of the depression to the apex) also has an influence on the optical properties (as defined herein) or the wetting properties.

[0168] According to an advantageous embodiment of the invention, an optoelectronic component with a structured substrate, in particular with an optoelectronically active layer, a contacting layer and / or a cover layer, is also included, wherein the surface consists of a structured and an unstructured region, wherein the structured region is formed by a first periodic dot structure with a first interference period in the micrometer or submicrometer range. The periodic dot structure is formed from inverse cones, wherein the inverse cones are periodically arranged with a distance relative to their respective saddle point or height center (circular base area) corresponding to the respective optical property to be adapted or the wetting effect to be achieved in the region as defined herein.The first periodic dot structure consists of one interference pixel or several interference pixels arranged offset from one another. A substrate structured in this way is characterized by having a periodic dot structure with exactly one interference period. There are no superimposed periodic structures with a second interference period. This results in more precise control of the substrate properties, in particular the transparency of the substrate, which is not compromised by the structuring due to the shallow structure depths resulting from the fact that each interference pixel is irradiated only once.

[0169] Preferably, the structured region of the surface of the substrate further comprises a second periodic dot structure, wherein the second periodic dot structure is formed from at least one second interference pixel (11) with a second interference period (p2), wherein the second interference pixel (11) has a periodic lattice of at least three cones or inverse cones with a second interference period (p2). The structured region is thus formed from a superposition of at least two periodic dot structures. The second interference pixel is then preferably offset, since the second periodic dot structure has an interference period that differs from the first interference period.

[0170] Optionally, the structured area has a periodic line structure with an interference period in the micro or submicrometer range; there is then a superposition of a periodic dot structure and a periodic line structure.

[0171] According to one possible embodiment, the studs or inverse studs of the structured region of a substrate have side surfaces. The side surfaces have a superimposed quasi-periodic or periodic line structure or a smooth surface. The superimposed quasi-periodic line structure is preferably generated by LIPSS. Alternatively, the superimposed quasi-periodic or periodic line structure can also be generated by subsequent structuring of the surface of the substrate, e.g., by further scanning the surface of the substrate using a laser structure application method, in particular direct laser interference structuring, wherein the structural parameters of the superimposed quasi-periodic or periodic line structure are selected to be smaller than those of the studs or inverse studs.

[0172] A smooth surface of the side surfaces (lateral surface) of the studs or inverse studs is preferably achieved by irradiating the individual studs or inverse studs no more than four times, in particular no more than three times, particularly preferably no more than twice, and most preferably only once during structuring by means of laser structure application methods, in particular by means of direct laser interference structuring. Each interference pixel is preferably generated by single irradiation. For the purposes of the invention, a surface is considered smooth if the mean roughness (R a ) according to DIN EN ISO 4287:2010 is less than 200 nm, preferably less than 50 nm, particularly preferably less than 20 nm, most preferably less than 5 nm.

[0173] A smooth lateral surface of the cones and / or inverse cones has the advantage over a rough surface that, particularly when electromagnetic radiation is irradiated, this radiation is not diffusely scattered back at the surface. The lateral surface of the cones or inverse cones thus serves, for example, when exploiting the trap effect, as a quasi-homogeneous mirror surface that reflects the portion of reflected incident electromagnetic radiation within the cones and / or inverse cones, in particular inverse cones, up to the saddle point. At each further reflection point within the lateral surface, a portion of the (remaining) electromagnetic radiation is coupled into the substrate, the outer surface and / or inner surface of which is formed from such a structured and an unstructured region (see, for example, Figs. 4 to 6).

[0174] Preferably, an overlap of possibly existing multiple interference pixels of one type is avoided. If an overlap of the interference pixels does occur, multiple irradiation of the same cone or inverse cone is avoided, so that the inverse cones of the overlapping, subsequently applied interference pixel are generated in the areas between the previously applied inverse cones, i.e., in the unstructured area. This makes it possible to achieve a superimposed structure consisting of several periodic dot structures without the occurrence of LIPSS. This enables reliable generation of the specified properties due to increased process reproducibility. This can be achieved, for example, by applying a structure shifted by 30% of the interference period with the same interference period.This allows multiple irradiation of the inverse cones to be avoided, even though there is an overlap of the interference pixels.

[0175] Preferably, the base of the stud or the inverse stud is circular or elliptical. The circular line is then free of any unevenness that typically occurs when etching through a mask with circular or elliptical openings.

[0176] As an alternative to the application of studs or inverse studs to the outer and / or inner surface of a substrate, the present invention also encompasses structuring in the volume of a substrate, in particular in the volume of a functional layer, in particular an optoelectronically active layer, a contacting layer and / or a cover layer (each as defined herein). If the structuring is carried out in the volume, i.e. in the interior of the substrate, preferably a flat and / or transparent substrate, in particular in the transparent material, the resulting structuring (i.e. the periodic dot structure of the structured substrate) is less sensitive to impacts and abrasion than conventional coatings. The inventors have discovered that structuring (also referred to as texturing herein) in the interior of the material (i.e.below the surface) introduces the properties described herein, in particular the anti-reflection properties, light path extension by diffraction at the grating and / or the reduced reflection due to the trapping effect into the material of the substrate.

[0177] The present invention therefore also includes an optoelectronic component which has at least the following components or layers:

[0178] • an optoelectronically active layer, a contacting layer and / or a cover layer, each of which independently has an outer surface and an inner surface, wherein the optoelectronically active layer, the contacting layer and / or the cover layer (also in the structured state) is at least partially transparent,

[0179] • at least one functional layer which is at least partially arranged or applied on the inner and / or outer surface of the optoelectronically active layer, the contacting layer and / or the cover layer, wherein the volume, in particular a plane in the volume, of the optoelectronically active layer, the contacting layer and / or the cover layer is each formed independently of one another from a structured and an unstructured region, wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel with a first interference period (pi), wherein the first interference pixel has a periodic grating of at least three cones or inverse cones, wherein the interference period (pi) of the first periodic dot structure is in the range from 50 nm to 50 pm.

[0180] The structured regions, in particular the dot structures, particularly preferably the cones and / or inverse cones in the volume of the substrate, particularly within a plane in the volume of the substrate, can each independently assume the structural parameters defined herein. To avoid duplication, the structured regions, in particular the dot structures, particularly preferably the cones and / or inverse cones in the volume of the substrate, and the structured regions, in particular the dot structures, particularly preferably the cones and / or inverse cones on the surface of the substrate, are used synonymously, so that the same structural parameters and configurations apply.In particular, by structuring within a plane within the volume of the substrate, the same optical properties, in particular the anti-reflection properties, light path extension due to diffraction at the grating, and / or reduced reflection due to the trapping effect, are introduced into the material of the substrate. Reference is made here to the explanations regarding the respective optical properties and the preferred structural parameters. In connection with point structures in the volume, in particular within a plane within the volume, the term "surface" (unless specified separately) is understood as synonymous with the plane arranged within the volume of the substrate.

[0181] Preferably, the structuring in the volume of the substrate is carried out by means of laser structure application methods, in particular direct laser interference structuring.

[0182] For structuring within the volume of a substrate, it may be appropriate to use the laser pulse duration and / or laser pulse energy preferred herein. This short laser pulse duration and / or laser pulse energy per laser pulse can prevent or at least minimize unwanted and / or uncontrolled melting of the substrate (e.g., in the form of a structural or chemical transformation), particularly as a result of local overheating, e.g., due to excessive energy input. This is particularly advantageous for the "sensitive" materials used herein that the substrates comprise or are made of.

[0183] Antireflection

[0184] With transparent and semi-transparent substrates, a portion of the incident electromagnetic radiation is partially reflected at the interfaces, depending on the material composition, and partially absorbed as it passes through the substrate, depending on the composition and thickness of the substrate. The remaining electromagnetic radiation is transmitted through the substrate and exits on the opposite side of the substrate. The transmittance (as a measure of the permeability of a medium / substrate) is therefore less than 100%. For example, the transmittance of commercially available flat glass is 83%-90%, depending on the glass thickness.In the case of perpendicular incidence of light, approximately 8% of the light is reflected at the two interfaces of commercially available flat glasses, which in the case of a layer are preferably arranged opposite one another, in particular plane-parallel, and which, when the substrate is designed as a cover layer, correspond to the outer surface and the inner surface, to the air or to another medium.

[0185] For the purposes of the invention, anti-reflection properties herein relate in particular to the increased transmission or diffraction of incident electromagnetic radiation with wavelengths in the spectral range optically visible to humans, in particular 380 to 780 nm, or in the range of ultraviolet radiation (in particular 100 to 380 nm) or infrared radiation (in particular 780 to 10,000 nm).

[0186] The structural parameters defined herein for producing a surface having anti-reflection properties, such as the interference period and structure depth, in particular the interference period, advantageously make it possible to reduce the proportion of reflected radiation at an interface of a substrate by at least 50%, preferably at least 70%, particularly preferably at least 80%, very particularly preferably at least 90%, in particular at least 95%. Using glass as the example of the substrate to be structured, the proportion of reflected light at one of the interfaces, i.e. at the inner and / or outer surface of the cover layer, can thereby advantageously be reduced to less than 4%, particularly preferably to less than 2.4%, particularly preferably to less than 1.6%, very particularly preferably to less than 0.8%, very particularly preferably to less than 0.4%.The adjustment of the anti-reflection properties by the formation of suitable structured and unstructured regions on the outer surface and / or inner surface of a substrate (as defined herein) is of great importance, in particular for the cover layer and / or the contacting layer, in particular for the cover layer, since the electromagnetic radiation escapes from the optoelectronic component into the environment through this layer(s) (in particular in the case of radiation-emitting cells) or enters it from the environment (in particular in the case of photovoltaic cells).

[0187] Nevertheless, the adjustment of the anti-reflection properties can be provided by the formation of a suitable structured and unstructured region, in particular a structured region, on the outer surface and / or inner surface of an optoelectronically active layer, since this can prevent or at least reduce radiation losses due to reflection at the interface of the optoelectronically active layer (in particular when electromagnetic radiation enters a photovoltaic cell or when electromagnetic radiation exits a radiation-emitting cell, in particular a light-emitting diode).

[0188] Structural depth

[0189] To produce a surface having anti-reflection properties, the inverse cones of an interference pixel according to a preferred embodiment of the present invention have a mean structural depth or profile depth on average d5o in the range from 5 nm to 10 pm, in particular in the range from 10 nm to 5 pm, particularly preferably in the range from 50 nm to 800 nm, most preferably from 100 nm to 500 nm. The structural depth of the inverse cones of an interference pixel is generally described by the mean structural depth (d5o), which defines the proportions of cones within an interference pixel with a certain structural depth smaller or larger than the specified value for the structural depth.

[0190] According to a preferred embodiment of the present invention, the inverse cones have a structural depth in the range from 5 nm to 800 nm, particularly preferably from 5 nm to 500 nm, very particularly preferably from 5 nm to 200 nm, in particular in the range from 5 nm to 150 nm or in the range from 10 nm to 100 nm. The fact that the inverse cones have such a small structural depth has the advantage that even very thin substrates, in particular the substrates of optoelectronic components, such as the optoelectronically active layer, the contacting layer and / or the cover layer, in particular functional layers as defined herein, with pronounced anti-reflection properties can be obtained without impairing the properties of the substrates. Such small structural depths can preferably be achieved by means of

[0191] Laser structure application processes, in particular direct laser interference structuring.

[0192] For the purposes of the invention, a structured substrate with anti-reflection properties also describes a substrate having a structured region consisting of overlapping structures, i.e., a further structure is superimposed on the first periodic dot structure, at least one structure having dimensions in the micrometer or submicrometer range, and at least one structure being formed from cones or inverse cones (as defined herein), which can be generated in particular by interfering laser beams. Preferably, the further structure is a line structure or a further periodic dot structure composed of cones or inverse cones.For example, when using interfering laser beams, the structured region, in particular the dot structure, consisting of overlapping structures, can be optimally adapted to the requirements of the respective application by appropriately configuring the parameters (selection of the laser radiation source, arrangement of the optical elements). Preferably, an optoelectronic component with a cover layer having an inner surface and / or outer surface with anti-reflective properties has a periodic dot structure that forms the structured region.

[0193] In contrast to conventional methods for influencing surface or interface properties (e.g., etching, sandblasting, polymer coatings), laser structure application methods, in particular direct laser interference structuring, do not require the entire surface to be structured. The proportion of the surface structured in this way (coverage of cones per unit area, which is determined by the number and diameter of the inverse cones), i.e., the proportion on the structured substrate, is preferably 3% to 99%, particularly preferably 5% to 80%, very particularly preferably 7% to 70%, in particular 10% to 50%.This not only allows for better detectability compared to conventional methods for structuring / coating substrates, but also has the advantage that fewer defects or more vulnerable structures are introduced into the plane of a substrate, especially into the surface, in order to achieve the properties defined herein.

[0194] Interference period

[0195] Antireflection properties on a surface are preferably achieved in that the structured region is formed by a periodic dot structure in the nanorange (submicrometer range) made up of inverse cones or cones with average dimensions in the submicrometer range, or at least has such a periodic dot structure in the nanorange. The periodic dot structure of an interference pixel has, in particular, an interference period, i.e., an average distance relative to the respective saddle point or height center of two adjacent inverse cones or cones of an interference pixel, of 100 nm to 1,000 nm, particularly preferably 200 nm to 700 nm, most preferably 200 nm to 450 nm.

[0196] The periodic dot structure in the nanometer range is preferably designed such that the structured substrate transmits electromagnetic radiation with a wavelength of more than 550 nm with a periodic dot structure of less than 1,000 nm, preferably more than 500 nm with a periodic dot structure of less than 750 nm, and most preferably more than 450 nm with a periodic dot structure of less than 600 nm. Depending on the structural depth of the inverse cones, wavelengths in the red and / or yellow light spectrum, the green light spectrum, and even the blue light spectrum can thus be transmitted into the substrate due to the anti-reflection properties.

[0197] According to a preferred embodiment of the invention, in order to produce a surface having anti-reflection properties, the surface preferably has a point structure which is formed in the form of periodically arranged, inverse cones, wherein the distance between the vertices of adjacent inverse cones (ie height center or centers of the elevations) is arranged on average in the range from 50 nm to 50 pm, preferably in the range from 50 nm to 20 pm, more preferably in the range from 100 nm to 1,000 nm, particularly preferably in the range from 100 nm to 600 nm.

[0198] For the purposes of the invention, anti-reflection properties refer to the increased transmission or diffraction of incident electromagnetic radiation with wavelengths in the range of visible light, in particular with wavelengths in the range from 400 nm to 780 nm as well as in the range of infrared radiation.

[0199] Thermal radiation, in particular with wavelengths in the range from 780 nm to 10 pm, preferably 780 nm to 0.1 mm. The substrate is characterized in that the periodic dot structure it comprises preferably has dimensions, i.e. interference periods, in the sub-micrometer range, particularly preferably in the nanometer range. The dimensions of the periodic dot structure are very particularly preferably in the wavelength range of electromagnetic radiation in the visible light range. Thus, the dimensions of the periodic dot structure are preferably in the range from 630 nm to 700 nm for transmitting or diffracting red light, in the range from 590 nm to 630 nm for transmitting or diffracting red and orange light, in the range from 560 nm to 590 nm for transmitting or diffracting red, orange and yellow light, and in the range from 500 nm to 560 nm for transmitting or diffractingDiffraction of red, orange, yellow, and green light in the range from 475 nm to 500 nm for transmission, or diffraction of red, orange, yellow, green, and turquoise light in the range from 450 nm to 475 nm for transmission, or diffraction of red, orange, yellow, green, turquoise, and blue light in the range from 425 nm to 450 nm for transmission, or diffraction of red, orange, yellow, green, turquoise, blue, and indigo light in the range from 400 nm to 425 nm for transmission, or diffraction of red, orange, yellow, green, turquoise, blue, indigo, and violet light. Thus, the anti-reflection properties of the substrate can be controlled by changing the dimensions of the periodic dot structure.

[0200] According to a preferred embodiment, the optoelectronic component is a light-emitting diode (LED). A periodic dot structure can be provided on the inner surface of the contacting layer and / or the cover layer. The periodic dot structure on the inner surface of the contacting layer and / or the cover layer can be designed such that high-energy light, in particular UV light or blue light, is reflected back into the LED, whereas light of a specific wavelength in the visible range generated, for example, by the optoelectronically active layer, in particular by phosphors in an optoelectronically active layer, can escape through the contacting layer and / or the cover layer into the environment. The reflected high-energy light can preferably serve to further excite the phosphors.Therefore, the dimensions of the periodic dot structure are preferably greater than 450 nm, particularly preferably greater than 475 nm, very particularly preferably greater than 500 nm. It can be provided that the dimensions of the periodic dot structures (independently of the aforementioned limit ranges) are preferably a maximum of 1,000 nm, particularly preferably a maximum of 900 nm, very particularly preferably a maximum of 800 nm, in particular a maximum of 700 nm.

[0201] In one embodiment of the invention, the method and device disclosed herein are suitable for producing a substrate comprising a periodic dot structure in the nanometer range, which was produced, for example, by laser interference structuring, and which is characterized by anti-reflection properties. For the purposes of the invention, anti-reflection properties also refer to the increased transmission or diffraction of incident electromagnetic radiation with wavelengths in the non-visible light range, in particular in the ultraviolet radiation (UV radiation) range, in particular with wavelengths in the range from 100 nm to 380 nm. The substrate is characterized in that the periodic dot structure it comprises preferably has dimensions in the nanometer range. A substrate structured in this way can advantageously be used in areas where protection against UV radiation is necessary.

[0202] However, the periodic dot structure used to generate the anti-reflection properties can also be superimposed with another dot structure and / or line structure to influence other properties, such as wetting properties. The resulting global dot structure, i.e., the resulting dot structure that forms the structured area, can then be fully periodic, quasi-periodic, or non-periodic.

[0203] The anti-reflection properties for visible light are particularly achieved when the dimensions of the structure produced, i.e. the interference period and dimensions of the individual cones or inverse cones, are in ranges smaller than the wavelength of visible light, i.e. preferably from and below 700 nm.

[0204] In physics, reflection is the rebound of an electromagnetic wave at an interface between materials with different refractive indices. The angle of reflection and the angle of transmission of light in transparent substrates can generally be calculated using Snell's law of refraction: n1sinθ1 = n2sinθ2, where θ1 and n2 represent the refractive index of air and the substrate, and θ1 and θ2 represent the angles of the incident and reflected beams, respectively.

[0205] Due to the periodic dot structure on the surface of the substrate, preferably a flat and / or transparent substrate, the refractive index of the substrate changes in such a way that a gradual refractive index results. This results in light with wavelengths longer than the interference period (p n) of the periodic dot structure is transmitted more intensely. Light with wavelengths less than or equal to the periodic dot structure is diffracted at the surface.

[0206] Anti-reflection properties in the sense of the invention refer to point structures whose dimensions lie in the range of the incident electromagnetic wave, such that the incident wave is diffracted away from the observer in such a way that no reflection is perceived as "disturbing". In addition, the term anti-reflection properties in the sense of the invention also includes the fact that the refractive index at the boundary between the first medium, for example air, and the substrate, preferably a flat and / or transparent substrate, is gradual, so that there is no clear transition from one medium to the other for the incident electromagnetic wave and the incident electromagnetic wave is increasingly transmitted. The refractive index of the structured substrate is gradual due to the generated periodic point structure. It decreases over the height of the structure, so that there is no clear air-medium transition.This results in increased transmission of incident electromagnetic waves with a wavelength greater than the interference period of the generated dot structure, and in diffraction of incident electromagnetic waves with a wavelength in the range of the interference period of the generated dot structure into the substrate.

[0207] Light path extension by diffraction at the grating

[0208] According to an advantageous embodiment, the structured region of an inner surface and / or outer surface of a cover layer of a photovoltaic component or a photovoltaic module has a periodic dot structure or is formed from a periodic dot structure. This periodic dot structure acts as a periodic grating and leads to an extension of the light path. This results in improved absorption and thus better efficiency, as explained below.

[0209] To ensure maximum light penetration into the photovoltaic component, the aim is to achieve a light incidence angle as perpendicular as possible to the outer surface of the optoelectronic component. As a result, the path the light travels through the optoelectronically active layer is not optimal and is actually too short to ensure optimal absorption of the light by the optoelectronically active layer, especially the absorption layer. Due to the necessary short charge carrier transport distance within the optoelectronically active layer, especially the absorption layer, to prevent charge carrier recombination, increasing the thickness of the optoelectronically active layer, especially the absorption layer, is not a suitable option.

[0210] Advantageously, the present invention can nevertheless contribute to an extension of the path which the light travels through the optoelectronically active layer, in particular the absorption layer.

[0211] Periodic dot structures arranged on an outer surface and / or inner surface of a cover layer of a photovoltaic component or a photovoltaic module act as a diffraction grating on incident light, resulting in diffraction effects. This deflects a portion of the light in its propagation direction. As a result, some of the light passes through the optoelectronically active layer not perpendicularly, but at a certain deflected angle. The resulting light path extension can advantageously increase the proportion of absorbed light, particularly without negatively affecting charge carrier extraction.

[0212] Furthermore, the adjustment of the light path extension by diffraction at a grating can also be achieved by forming a suitable structured and unstructured region, in particular a structured region, on the outer surface and / or inner surface of an optoelectronically active layer. A periodic structure created at the interface to the optoelectronically active layer leads to a suitable deflection of the propagation direction of the electromagnetic radiation when electromagnetic radiation enters a photovoltaic cell, thus leading to the aforementioned light path extension and the associated increase in absorption and consequently also in efficiency.

[0213] Reduced reflection due to the trap effect

[0214] The reduction of reflection due to the trap effect (as defined herein) by the formation of suitable structured and unstructured regions on the outer surface and / or inner surface of a substrate is of great importance, in particular for the optoelectronically active layers, in particular for the optoelectronically active layers in photovoltaic cells, since within this layer(s) the absorption and / or interaction between the electromagnetic radiation incident on the optoelectronic component or optoelectronic module and the light-absorbing material within the optoelectronic layer ensures a high efficiency of the optoelectronic component.

[0215] Nevertheless, the described reduction in reflection due to the trapping effect can increase light extraction in a light-emitting component or a module comprising multiple light-emitting components. This can advantageously increase the efficiency, particularly the luminous efficacy / light release, of the light-emitting component or light-emitting module.

[0216] According to a preferred embodiment of the invention, the structured regions which reduce the reflection due to the trapping effect within the structured regions are arranged in such a way that, with respect to the direction of incidence of electromagnetic radiation, preferably light, inverse cones are arranged at this interface into which the light enters, in such a way that they are formed into the substrate, in particular into the optoelectronically active layer.

[0217] According to a preferred embodiment of the invention, for adjacent layers whose surfaces are formed from a structured and an unstructured region, it is provided that, with respect to the direction of incidence of electromagnetic radiation, preferably light, onto the interface between the two layers, the layer from which the electromagnetic radiation emerges and passes into the adjacent layer has a structured region formed from cones (as defined herein). In contrast, the structured region of the layer adjacent to this layer, into which the light enters, is formed from inverse cones. If, for example, an optoelectronically active layer is arranged adjacent to a contacting layer within a photovoltaic cell, the interface between the two layers preferably has cones orinverse cones, wherein the inverse cones are formed in the outer surface of the optoelectronically active layer, and wherein, complementarily thereto, the inner surface of the contacting layer has a structured region formed from cones (so-called “Lego principle”).

[0218] According to an advantageous embodiment, the structures are produced on an outer surface and / or inner surface of a cover layer and / or a contacting layer.

[0219] Such a structure for reducing reflection due to the trapping effect can also be created by forming a suitable structured and unstructured region, in particular a structured region, on the outer surface and / or inner surface of an optoelectronically active layer. Reducing reflection is particularly relevant at an interface to the optoelectronically active layer.

[0220] According to an advantageous embodiment, the optoelectronic component is a photovoltaic component and the point structures generated on the optoelectronically active layer are inverse cones.

[0221] According to an alternative embodiment, the optoelectronic component is a light-emitting component, preferably an LED, and the dot structures generated on the optoelectronically active layer are cones. Thus, the described reduction in reflection due to the trapping effect can increase the light coupling in a photovoltaic component or a module comprising multiple photovoltaic components, and the light coupling out in a light-emitting component or a module comprising multiple light-emitting components. This can advantageously increase the efficiency of the optoelectronic components or optoelectronic modules.

[0222] When utilizing the trap effect, the lateral surface of the pegs or inverse pegs serves as a mirror surface, preferably a quasi-homogeneous mirror surface, which reflects the portion of reflected incident electromagnetic radiation within the pegs and / or inverse pegs, in particular inverse pegs, up to the saddle point, wherein at each further reflection point within the lateral surface, a portion of (remaining) electromagnetic radiation is coupled into the substrate, whose outer surface and / or inner surface is formed from such a structured and an unstructured region (see, for example, Figs. 4 to 6). According to a preferred embodiment of the invention, the lateral surface of the pegs or inverse pegs is smooth.

[0223] Structural depth

[0224] To create a surface that has properties for reducing reflection due to the trap effect, the cones or inverse cones of an interference pixel according to a preferred embodiment of the present invention have an average structural depth or profile depth on average d5o in the range from 0.05 pm to 20 pm, particularly preferably in the range from 0.05 pm to 10 pm, most preferably from 0.1 pm to 5 pm, in particular 0.1 pm to 2 pm. The structural depth of the inverse cones of an interference pixel is generally described by the average structural depth (d5o), which defines the proportion of cones within an interference pixel with a certain structural depth that is smaller or larger than the specified value for the structural depth. A structural depth designed in this way, for example, hasthe advantage that a high proportion of remaining electromagnetic radiation, which is not yet coupled into the substrate during the first interaction with the surface of the substrate, is passed on by further interaction with the lateral surface within the peg or inverse peg up to its saddle point and as a result (no longer escaping the peg or inverse peg) is coupled into the substrate with an efficiency of more than 90%, preferably more than 95%, particularly preferably more than 98%, very particularly preferably more than 99%. The structural depth of a point structure having pegs in the sense of the invention is the average structural depth of a point structure having pegs, that is to say the statistical mean of the distance from the surface to the height center of the pegs.Even though the cones generally protrude from the structure, the mean distance of the height centers of the cones to the surface is nevertheless referred to as structure depth or mean structure depth d5o in analogy to the inverse cones.

[0225] For the purposes of the invention, a structured substrate or a cover layer with properties for reducing reflection due to the trap effect also describes such a substrate which has a structured region consisting of superimposed structures, i.e., wherein a further structure is superimposed on the periodic dot structure, wherein at least one structure has dimensions in the micrometer or submicrometer range, and wherein at least one structure is formed from cones or inverse cones (as defined herein), which can be generated in particular by interfering laser beams. Preferably, the further structure is a line structure or a further periodic dot structure composed of cones or inverse cones.

[0226] For example, a global dot structure, especially a global dot structure consisting of overlapping structures, can be optimally adapted to the requirements of the respective application when using interfering laser beams by appropriately configuring the parameters (selection of the laser radiation source, arrangement of the optical elements). Preferably, an optoelectronic component with a cover layer having a surface or interface with properties for reducing reflection due to the trapping effect has a periodic global dot structure.

[0227] In contrast to conventional methods for influencing surface or interface properties (e.g., etching, sandblasting, polymer coatings), it is not necessary for the entire surface to be structured (and / or coated as in conventional methods). The proportion of the surface structured in this way (coverage of cones per unit area, which is determined by the number and diameter of the inverse cones), i.e., the proportion on the structured substrate, is preferably 3% to 99%, particularly preferably 5% to 80%, very particularly preferably 7% to 70%, in particular 10% to 50%.This not only allows for better detectability compared to conventional methods for structuring / coating substrates, but also has the advantage over these methods that fewer defects or more susceptible structures are introduced into the plane of a substrate, in particular into the surface, in order to achieve the properties defined herein. According to a preferred embodiment of the present invention, the structured substrate does not just comprise a single interference pixel of one type, e.g. a first interference pixel, a second interference pixel and / or a third interference pixel, but rather a plurality of interference pixels of one type, e.g. a plurality of first interference pixels and / or a plurality of second interference pixels, each independently of one another within a plane in at least one spatial direction (x and / or y alignment), particularly preferably in two spatial directions (planar), adjacent and repetitively offset from one another. For example,It can be provided that, in a first step, at least a plurality of first interference pixels (10) are applied to a plane on a surface or in the volume of the substrate to be structured, arranged adjacent to one another within a plane in at least one spatial direction and repetitively offset from one another (see, for example, Fig. 15), and in a second step, a plurality of second interference pixels (11) are applied superimposed on these plurality of first interference pixels (10) within a plane, adjacent to one another in at least the same spatial direction and repetitively offset from one another. Nevertheless, it can be provided that these plurality of first interference pixels (10) and several second interference pixels (11) are applied to the plane alternately, i.e. alternately - i.e. a first interference pixel, then a second interference pixel and again from the beginning.

[0228] This advantageously increases the area where reflection is reduced by the trapping effect. Furthermore, an arrangement in which a plurality of interference pixels are arranged adjacent to one another, repetitively offset from one another in at least one spatial direction, opens up a number of adjustable degrees of freedom that can be used to efficiently influence the surface properties.

[0229] By arranging a plurality of first interference pixels (10) and a plurality of second interference pixels (11), specific properties, in particular a reduction in reflection, i.e., a reduction in the light that is neither transmitted nor absorbed, can be achieved / applied over a large area, in particular across a plane of the substrate spanned by a surface of the substrate, or within the volume of the substrate. Such structuring with a plurality of first interference pixels (10) and a plurality of second interference pixels (11) can be achieved, for example, by scanning the substrate with a polygon scanner.

[0230] The superimposed interference pixels of different types, e.g., a first interference pixel, a second interference pixel, and / or a further interference pixel, can optionally form a periodic or a non-periodic global dot structure globally (i.e., across the extent of the plane to be structured). A fully periodic global dot structure is generated or exists when the pixels of an interference pixel of a first type and the superimposed pixels of an interference pixel of a different type are spaced apart from each other by a whole multiple (e.g., 2, 3, 4, 5) of the interference period (p n ) are shifted from each other in one spatial direction. This results in a fully periodic pattern over the extent of the plane to be structured, the period of which corresponds to the interference period (p n). A quasi-periodic global dot structure is created or exists when the pixels of a first type and the superimposed pixels of an interference pixel of a different type are spaced from each other by an equal multiple (e.g. 0.5; 1.3; 2.6) of the interference period (p n ) are shifted relative to one another in a spatial direction. In contrast, a non-periodic global point structure is generated by the pixels of a first type and the superimposed pixels of an interference pixel of another type, or is present when the superimposed first interference pixels and the superimposed second interference pixels have different interference periods and / or the adjacent, repetitively offset pixels of at least one type of an interference pixel are rotated, e.g., applied in a successively rotated manner.

[0231] According to a preferred embodiment of the present invention, the global point structures, comprising at least a plurality of first interference pixels of at least one first interference period (pi) and a plurality of second interference pixels of at least one second interference period (p2), are quasi-periodic or non-periodic, particularly preferably non-periodic, wherein such a global point structure is preferably formed from the superposition of at least one first interference pixel and one second interference pixel, which are each arranged adjacent to one another in at least one spatial direction and repetitively offset from one another and each form a periodic or quasi-periodic global point structure.

[0232] It can be provided that first interference pixels (10) and / or second interference pixels (11) arranged adjacent to one another have varying structural parameters, selected from the group comprising the interference period of the interference pixel, the structural depth of the inverse cones, the diameter of the inverse cones, the shape of the inverse cones and the size of the inverse cones. This advantageously makes it possible to locally generate a high degree of disorder, i.e. non-periodic structures, whereby undesired or disruptive optical effects, such as moiré effects or color effects that arise through diffraction on applied microstructures, are minimized or prevented. According to a preferred embodiment of the invention, the interference period of the point structure of at least one further interference pixel of a type, e.g.Each interference pixel of a first interference pixel, each interference pixel of a second interference pixel, and / or each interference pixel of a third interference pixel are substantially identical, i.e., they differ by a maximum of 0% to 2.0%, particularly preferably by a maximum of 0% to 1.0%. The interference periods are most preferably identical. This allows the parameters of the laser interference structuring device for applying the interference pixels to the plane of the substrate to be kept constant, which minimizes the effort and the formation of defective structures.

[0233] According to a preferred embodiment of the present invention, the adjacent, repetitively offset interference pixels of one type, for example the first interference pixel, the second interference pixel and / or the third interference pixel, are rotated relative to the preceding interference pixel of this one type about an axis of rotation (i.e., a normal to the plane) arranged within the interference pixel (preferably about a central one), for example alternately or successively rotated relative to the previous one. Preferably, the subsequent interference pixel is rotated relative to the preceding interference pixel of the interference pixels of one type in the range of 1° to 90°, furthermore in the range of 3° to 85°, particularly preferably by 5° to 80°, very particularly preferably by 10° to 75°, in particular in the range of 15° to 60°.As a result, a high degree of disorder, i.e. non-periodic structures, is generated globally over a plane of the substrate that is spanned by a surface of the substrate or within the volume of the substrate, which also minimizes or prevents undesired or disturbing optical effects, such as moiré effects or color effects that arise from diffraction on applied microstructures.

[0234] The generation of structured regions having a non-periodic global dot structure can be advantageous. A superposition of first and second interference pixels having identical interference periods can result in periodic dot structures in which the undesired moiré effect occurs, so that, according to an advantageous embodiment, the interference periods of superimposed interference pixels are varied by a non-integer factor. A disadvantageous change in the color behavior, such as can occur due to diffraction effects on the introduced structures, is also avoided by a high degree of disorder. To generate a non-periodic global dot structure, the offset between the interference pixel of a first type and the interference pixel of a second type, e.g., the second interference pixel and the first interference pixel, is preferably in the range of

[0235] 5% < x < 50%, preferably in the range of 10% < x < 50%, in particular in the range of 20% < x < 50%, particularly preferably in the range of 25% < x < 45% of the interference period. If the periodic dot structure is designed such that an interference pixel of a further type is provided, at least a third interference pixel, this is arranged superimposed on the interference pixel of the previous type in such a way that the offset between the interference pixel of the further type, e.g. the third interference pixel, and the second interference pixel is preferably in the range of 5% < x < 50%, preferably in the range of 10% < x < 50%, in particular in the range of 20% < x < 50%, particularly preferably in the range of 25% < x < 45% of the interference period. An offset which lies below the interference period leads to an increase in the structure density orDensity of the dot structure, which results in an increase in the density of the cones or inverse cones that potentially act as traps and thus advantageously results in improved light coupling or light extraction.

[0236] According to a preferred embodiment of the present invention, the structured substrate, in particular the structured cover layer and the dot structure applied to the surface of the cover layer, has at least one further type of interference pixel with a further interference period (p n), for example a third interference pixel (12) with a third interference period (p3), wherein the further, for example the third interference pixel (12) according to the aforementioned claims is arranged superimposed on the first interference pixel (10) and second interference pixel (11). As a result, further defects (i.e. point structures in the micrometer and submicrometer range) can advantageously be created in the plane of the substrate to be structured. A higher number of cones or inverse cones increases the number of traps, thereby advantageously reducing the proportion of reflected light.

[0237] This can also advantageously increase the degree of disorder, ie non-periodic structures, whereby undesirable or disturbing optical effects, such as moiré effects or color effects, which arise from diffraction on applied microstructures, can be minimized or prevented.

[0238] Interference period

[0239] Properties in which the reflection is reduced due to the trap effect are preferably achieved in that the global point structure which forms the structured region is a non-periodic global point structure made of inverse cones with average dimensions in the micrometer range. The periodic point structure of an interference pixel has in particular an interference period, i.e. a mean distance based on the respective saddle point or midpoint of height of two adjacent cones of an interference pixel of 1 pm to 50 pm, particularly preferably 1 pm to 30 pm, very particularly preferably 1 pm to 20 pm. This preferably non-periodic point structure in the micrometer range can have a further structure in the nanometer range superimposed on it, the average dimension of the superimposed structure preferably having dimensions in the range of the laser wavelength A, or A / 2, in particular from 100 nm to 1.000 nm, preferably from 200 nm to 500 nm, particularly preferably from 200 nm to 450 nm. For the purposes of the invention, such a structure is also referred to as a hierarchical structure.

[0240] Hierarchical structuring refers to a structure in which a first structure with dimensions in the micrometer or submicrometer range, in particular in the micrometer range, which corresponds to an interference pattern, is overlaid by a further structure which has dimensions that are smaller than the dimensions of the first structure and which is formed, for example, by a self-organization process. Preferably, the dimensions of the further structure, the structure in the nanometer range superimposing the dot structure in the micrometer range, which is formed, for example, by a self-organization process, are in the range of 1% to 30%, particularly preferably in the range of 1% to 10% of the dimensions of the first structure, which corresponds to an interference pattern.

[0241] In particular, the structure superimposed on the point structure in the micrometer range has a periodic wave structure in the nanometer range, preferably a fully periodic wave structure, wherein the material on the surface of the substrate in the region of the superimposed structure has a sequence of wave crests and wave troughs whose periodicity lies in the submicrometer range, preferably in the range from 100 nm to 1,000 nm, particularly preferably from 200 nm to 500 nm, in particular in a range as defined herein for anti-reflection properties. This allows additional, advantageous anti-reflection properties to be introduced into the structured plane, in particular on the surface of the substrate. The structures in the nanometer range ensure that light incident on the substrate is reflected less or is reflected at such a shallow angle that it does not have a "disturbing" effect when the material surface is viewed normally.The periodic dot structure in the nanometer range is preferably designed such that the structured substrate transmits electromagnetic radiation with a wavelength of more than 550 nm for a periodic dot structure of less than 1,000 nm, preferably more than 500 nm for a periodic dot structure of less than 750 nm, and most preferably more than 450 nm for a periodic dot structure of less than 600 nm. Depending on the structural depth of the inverse cones, wavelengths in the red and / or yellow light spectrum, the green light spectrum, and even the blue light spectrum can thus be transmitted into the substrate.

[0242] The average structural depth of this structure in the nanometer range, which overlays the dot structure in the micrometer range, is preferably in the range of 10 nm to 500 nm.

[0243] Due to the dimensioning of the nanometer-scale structure overlying the micrometer-scale point structure in relation to the micrometer-scale point structure, it is advisable to apply this periodic nanometer-scale structure, preferably a fully periodic wave structure, after applying the micrometer-scale point structure, since otherwise the overlying nanometer-scale structure could be destroyed by applying the much larger micrometer-scale point structure.

[0244] The wave structure, which overlies the periodic dot structure of inverse cones with average dimensions in the micrometer range, can be formed during the structuring process, i.e., when a laser pulse impinges on the substrate to be structured, as a result of the appearance of a high-intensity region. Structuring occurs through a self-organization process stimulated by the at least partial melting of the substrate material by means of a laser pulse in a high-intensity region. In particular, the wave structure is generated using laser-induced periodic surface structures (LIPSS), the appearance of these surface structures being coupled to the generation of the dot structures by means of interfering laser beams.

[0245] Alternatively, the wave structure superimposed on the point structure according to the invention consisting of inverse cones with average dimensions in the micrometer or submicrometer range can also be produced by subsequently applying a further interference pixel to the surface of the (pre-structured) substrate, wherein the structures generated with the further interference pixel have an interference period, based on the cones formed by the further interference pixel, on average in the range from 100 nm to 1,000 nm, preferably in the range from 200 nm to 500 nm.

[0246] There are numerous technical applications for hierarchical structures, such as in the production of substrates with hydrophobic or superhydrophobic as well as hydrophilic or superhydrophilic surfaces and substrates with anti-icing or anti-fogging properties in addition to the substrates mentioned above with properties for reducing reflection due to trapping effects.

[0247] This advantageously enables the surface structuring of a substrate, for example, with properties for reducing reflection due to trapping effects caused by interfering laser beams and by utilizing laser-induced periodic surface structures, without having to accept long processing times or a large number of successively executed process steps. The invention thus enables the simultaneous creation of hierarchical structures, which can be used in the technical field both in the area of ​​substrates with anti-reflection properties and in the area of ​​self-cleaning, hydrophobic or superhydrophobic, as well as hydrophilic or superhydrophilic substrates with anti-reflection properties and / or anti-fogging properties.

[0248] Anti-soiling properties / wetting properties

[0249] Particularly in the case of optoelectronic components or optoelectronic modules used outdoors and exposed to environmental influences, the layers or surfaces that seal off the environment quickly become dirty or tend to clog the surface with the formation of condensation, particularly in the form of fog or mist, thereby reducing the permeability of light entering or exiting the optoelectronic cell. This reduces, for example, the efficiency of photovoltaic cells. It is therefore advisable to modify the outer surface that seals off the optoelectronic component or optoelectronic module from the environment in such a way that the wetting properties of the surface are improved or increased, so that the substrate has anti-dirt and / or anti-fogging properties.

[0250] Due to the very small structural dimensions that can be produced, the device and method disclosed herein are also suitable for producing surfaces with hydrophobic and / or superhydrophobic as well as hydrophilic and / or superhydrophilic properties. It is advantageous that the application of the periodic dot structure to the surface of the substrate (as defined herein), in particular the periodic dot structures, does not impair the optical properties, in particular the original transparency of the substrate, especially when applied to the outer surface of a cover layer.

[0251] Surfaces with anti-soil properties are characterized by having either highly hydrophobic or highly hydrophilic properties. The degree of hydrophobicity or hydrophilicity of a surface can be determined by the water contact angle of a wetted surface. A water contact angle of less than 90° is referred to as hydrophilic, and a water contact angle of more than 90° is referred to as hydrophobic.

[0252] In the sense of the invention, a surface has an anti-dirt property if, when wetted with water, it has a water contact angle of less than 20° or greater than 130°, preferably less than 10° or greater than 140°, particularly preferably less than 5° or greater than 150°.

[0253] The water contact angle of a surface is determined using droplet contour analysis. This image analysis method uses the shadow image of a droplet positioned or lying on the surface, analyzing its shape on the surface. A droplet containing 2 μl of deionized water is used on the surface of the substrate. The ambient temperature is 22°C.

[0254] A further effect that can be achieved with structured surfaces is a reduced adhesion of solid particles, in particular dirt and dust particles. This means that a smaller proportion of solid particles adhere to the surface. Such structuring applied to the outer surface of a cover layer advantageously leads to a cleaner outer surface of the cover layer and, in the case of materials that are at least partially transparent, preferably transparent, also to better transparency of the cover layer, since dirt and dust particles also absorb or reflect some of the light. This can improve the coupling and decoupling of light and increase the efficiency of the optoelectronic components. The interference period is preferably selected to be smaller than the average particle size of the particles whose adhesion is to be reduced. This disrupts adhesion or can significantly reduce it.This effect is also called the anti-soiling effect.

[0255] Particularly for optoelectronic components, where surface transparency is very important, it is very problematic that particles, especially small particles such as dust, adhere very strongly to a surface. This applies particularly to dust particles with a diameter of 0.2 pm to 100 pm; dust particles with a diameter of 0.5 to 20 pm are also particularly relevant, and diameters of 1 to 10 pm are even more relevant. These particles reduce the transparency of the surface and thus decrease the efficiency of the optoelectronic component, in particular the photovoltaic component or the light-emitting diode. According to an advantageous embodiment, the first periodic dot structure or a line structure, preferably a superimposed line structure, has interference periods of less than 100 pm, preferably less than 20 pm, and very particularly preferably less than 10 pm.According to a particularly preferred embodiment, the interference periods range from 50 nm to 5 pm. Due to the anti-soiling effect occurring on the surface with respect to dust particles with diameters larger than the respective interference period, the van der Waals forces acting between the dust particles and the surface of the cover layer are reduced by the structuring. This leads to a reduction in the adhesion of the dust or particles, in particular dirt particles, to the surface of the cover layer due to the reduced contact area between the dust particles and the surface.

[0256] The structure is selected so that the functional laser structure is just smaller than the average particle size distribution. The greater the deviation from the average particle size, the stronger the anti-soiling effect.

[0257] Preferably, the structure depth, in particular the average structure depth in the statistical mean d50, of the first periodic dot structure and / or the superimposed line structure, i.e., in combination with the above-mentioned interference periods to optimize the anti-soiling effect, is in the range of 10 nm to 20 pm, preferably 20 nm to 1 pm, preferably in the range of 50 nm to 200 nm. Advantageously, the anti-soiling effect can be achieved without significantly reducing transparency. Advantageously, the human eye does not see the structuring, although the dust "sees" it. Such small structure depths also require only low laser pulse energies or laser pulse powers, so that the process speed is advantageously very high, with surface speeds of 0.01 m. 2 / min and higher.

[0258] These structures can reduce the adhesion of moon dust, cement dust, or desert dust. Furthermore, this type of structure can achieve a high level of transparency, at least 50%, preferably at least 70%, particularly preferably at least 90%. A particularly advantageous property is that the transparency of the unstructured surface is reduced by the structuring in a sub-range of electromagnetic radiation, preferably by a maximum of 10%. Possible sub-ranges include, for example, electromagnetic radiation in the ultraviolet (UV) light range from 100 nm to 380 nm, in particular UV-A from 315 nm to 380 nm or UV-B from 280 nm to 315 nm or UV-C from 100 nm to 280 nm, visible light from 380 nm to 780 nm, or in a range that also includes infrared light, from 780 nm to 5.000 nm or in a range of infrared light (heat radiation) or in a range of microwave radiation, especially radar beams in the wavelength range from 1 mm to 10 m, or another subrange adapted to the wavelength of the light source according to the desired application, particularly in the field of metrology. For example, high transparency can be selected even in the near infrared, although transparency in the visible range can be significantly lower.

[0259] This makes optoelectronic components with such structures particularly suitable for applications in the automotive industry and in aerospace for energy generation and / or lighting.

[0260] However, the periodic dot structure used to generate anti-soiling properties and / or optimize wetting properties can also be superimposed with another dot structure and / or line structure to influence other properties, such as wetting properties. The resulting global dot structure, i.e., the resulting dot structure that forms the structured area, can then be fully periodic, quasi-periodic, or non-periodic.

[0261] Hydrophobic properties

[0262] Hydrophobic properties depend on both the chemical and surface properties, particularly the surface roughness, of a substrate. The inventors have now surprisingly discovered that, by the method according to the invention, particularly hydrophobic substrates can be treated with superhydrophobic and self-cleaning properties by introducing structures in the micrometer and submicrometer range, particularly overlapping structures (as defined herein). Substrates with superhydrophobic properties are particularly preferably substrates with a hierarchical surface structure.Hierarchical surface structuring is defined here as a surface with regular structures with dimensions in the micrometer range, which in turn have a surface structure with dimensions in the submicrometer range. Such hierarchical structuring can lead to high surface roughness.

[0263] The inventors have also discovered that substrates structured primarily by a device or method disclosed herein are characterized by pronounced hydrophobic properties on the surface of a substrate. By means of the device and method disclosed herein for producing dot structures with dimensions in the micrometer and / or submicrometer range, structuring to produce a surface texture, in particular a surface roughness on the surface of a substrate, is also possible, which results in the substrate having hydrophobic or superhydrophobic properties. Hydrophobic material properties can be created by using direct laser interference structuring to create a structure with dimensions in the micrometer and / or submicrometer range. In a preferred embodiment, a structure with dimensions in the micrometer range is first created on the surface.Next, by moving the beam splitter element in the laser beam path, a structure with dimensions in the submicrometer range is generated on the surface of the first structure, preferably with multiple irradiation of the substrate. The hierarchical structure thus created has hydrophobic or superhydrophobic properties.

[0264] To create a substrate with hydrophobic properties, it is also conceivable to create only a dot structure with dimensions in the micrometer or submicrometer range, without moving the beam splitter element in an intermediate step. The dimensions mentioned refer to the interference periods or the size of the intermediate unstructured sections.

[0265] Advantageously, optoelectronic components with hydrophobic and / or superhydrophobic properties can be produced in a technically easily feasible manner using the same method and on the basis of the same device by creating a periodic dot structure in the micrometer or submicrometer range and / or a periodic dot structure with a hierarchical structure in the micrometer and submicrometer range. By moving the beam splitter element, at least two, but also any number of additional structurings can be realized on the surface of the substrate without further changes to the structure, e.g., without replacing optical elements or moving the substrate. This increases both the precision in the alignment of the structures and the speed of the process compared to conventional methods or devices.

[0266] The inventors have established a relationship between the surface properties of a substrate and the formation of ice on its surface. In particular, so-called anti-icing properties can be created, for example, on the outer surface of a cover layer, if the structure size on the surface of a substrate is sufficiently small. The results have shown that a substrate with superhydrophobic properties (preferably as defined herein) can also exhibit anti-icing properties.

[0267] For the purposes of the invention, anti-icing properties mean that no or very little water freezes on the surface of a substrate, whereby this property is due to the surface properties, in particular the surface roughness.

[0268] Such a substrate can be used advantageously in the aerospace sector, in wind turbines, in the field of automotive components or even telecommunications and antenna technology to protect exposed components from icing.

[0269] Hydrophilic properties

[0270] The inventors have further discovered that substrates structured primarily by a device or method disclosed herein are characterized by pronounced hydrophilic properties on the surface of a substrate. Using the device and method disclosed herein for generating dot structures with dimensions in the micrometer and submicrometer range, structuring to create a surface texture, in particular a surface roughness, on the surface of a substrate is also possible, which results in the substrate having hydrophilic or superhydrophilic properties.

[0271] Hydrophilic material properties can be created by using direct laser interference structuring to create a point and / or line structure with dimensions in the micrometer and / or submicrometer range. In a preferred embodiment, a structure with dimensions in the micrometer range is first created on the surface. Then, by moving the beam splitter element in the laser beam path, a structure with dimensions in the submicrometer range is generated on the surface of the first structure, preferably with multiple irradiation of the substrate. The hierarchical structure thus created has hydrophilic or superhydrophilic properties.

[0272] To produce a substrate with hydrophilic properties, it is also conceivable to create only a structure with dimensions in the micrometer or submicrometer range, without moving the beam splitter element in an intermediate step. According to one embodiment, the structured region is created by single irradiation, thus avoiding LIPSS structures. This allows reliable and effective structuring to be achieved. Advantageously, substrates with hydrophilic and / or superhydrophilic properties can thus be produced in a technically easily feasible manner using the same method and on the basis of the same device by creating a periodic dot structure in the micrometer or submicrometer range and / or a periodic dot structure with a hierarchical structure in the micrometer and submicrometer range.By moving the beam splitter element, at least two, but also any number of, additional structures can be created on the substrate surface without further modification of the structure, for example, without replacing optical elements or moving the substrate. This increases both the precision in the alignment of the structures and the speed of the process compared to conventional methods or devices.

[0273] According to an advantageous embodiment of the method, partial beams are generated in the laser interference method by means of a beam splitter element (2), and the interference period (p) of an interference pixel, preferably the first interference period (pi) of the first interference pixel (10), is continuously adjusted by displacing the beam splitter element (2). The other optical elements are preferably fixed.

[0274] An optoelectronic component produced by the method and device disclosed herein is also suitable for further processing by means of a coating process, wherein the optoelectronic component can receive a physical and / or chemical coating. Such a coating can enhance the properties of the structured substrate, for example, the anti-reflection properties and / or hydrophilic and / or hydrophobic properties. Application of a chemical spray coating and / or application of a coating by means of chemical vapor deposition and / or sputtering is conceivable.

[0275] The invention thus also encompasses an optoelectronic component which has a cover layer with a coating. In this case, a coating, preferably a protective coating, preferably a transparent protective coating, is arranged on the structured surface of the cover layer. Such a coating, preferably a protective coating, preferably a transparent protective coating, is preferably very thin and has, for example, a thickness of 1 nm to 5 pm. As a result, the structure of the structured surface is essentially retained. The coating, preferably a protective coating, preferably has a high hardness, whereby the longevity of the structured surface of the cover layer or of the optoelectronic component is increased and thus improved. What is relevant here is that the underlying substrate already has a structured surface, i.e. not only the coating is structured.By combining a structured top layer and a thin coating arranged on top of it, the surface modification in combination with the properties of the materials can generate special surface properties, in particular special wetting properties of the resulting structured surface.

[0276] The coating is arranged on the optoelectronic component on the structured cover layer in such a way that the first dot structure is formed in the coating and is also formed in the underlying layer adjacent to the coating, in particular the cover layer.

[0277] The choice of coating material allows the water contact angle of the surface to be precisely adjusted. The surface tension is modified by functional end groups within the coating, resulting in either hydrophilic or hydrophobic properties.

[0278] According to an advantageous embodiment, the coating material has hydrophobic wetting properties. This allows superhydrophobic properties to be achieved even on an underlying hydrophilic material, such as glass.

[0279] According to a further advantageous embodiment, the coating material has hydrophilic wetting properties. This allows for the creation of a particularly durable and stable superhydrophilic surface.

[0280] Suitable materials for a hydrophobic coating are (nano-)coatings based on silicon dioxide, fluorinated silanes and fluoropolymer coatings, manganese oxide-polystyrene (Mn02 / PS) nanocomposites, zinc oxide-polystyrene (ZnO / PS) nanocomposites, coatings based on calcium carbonate and also carbon nanotube structure coatings, i.e. a coating which has carbon nanotubes, preferably transparent carbon nanotube structure coatings.

[0281] Suitable materials for a hydrophilic coating are, for example, ceramic materials such as BeO-based, MgO-based, TiO2-based, Al2O3-based, ZrO2-based, ZnO-based, SnO-based, SiO2-based, aluminosilicate-based coatings, silicate-based coatings, spinel ceramics such as Mg-Al spinel, aluminum oxynitride (ALON), yttrium aluminum garnet, yttrium oxide-based coatings, mixed oxide ceramics such as ATZ / ZTA, silicon carbide (SiC), tungsten carbide (WC), aluminosilicates, (layered) silicate materials and combinations thereof, TiO2-based coatings, hydrogels / sol-gel coatings, acrylate-based polymers / acrylamide copolymers, polyurethane-based coatings or even polyalcohol diepoxide.

[0282] Advantageously, coatings such as hydrogels, acrylate-based polymers, silicon dioxide-based coatings, and even carbon nanotubes are transparent at low thicknesses, especially up to 5 pm, and thus exhibit high transmission. This allows the creation of cover layers with a coating that exhibits high transmission (as described herein).

[0283] Advantageous surface modifications include the provision of hydrophobic polymers, such as alkyl chains and / or alkylsilane and / or fluorinated alkyl chains, which are preferably embodied as polymer brushes. Polymer brushes within the meaning of the present invention are dense layers of polymer chains that are bonded or grafted to a surface, often at one end of the chains. The methods used to modify surfaces to create chemical attachment points for the chains are known to those skilled in the art and include, for example, bioconjugation, radical / anionic / cationic chain polymerization, particularly preferably living chain polymerization and / or surface-induced polymerization (SIP). This allows surface properties such as wettability and adhesion to be subsequently improved after structuring and processing steps. These layers preferably have a layer thickness of 10 to 250 nm, more preferably of 20 to 150 nm.These layers are preferably transparent and allow physical properties such as hydrophobicity to be influenced while the optical properties are not affected.

[0284] In a particularly preferred embodiment, the coatings are advantageously designed so that a change in conditions, such as temperature or pH, influences the surface properties. Thus, the hydrophobicity of the material can be controlled, e.g., by increasing the temperature. This advantageously allows for the control of wettability and adhesion.

[0285] Layer thicknesses can be determined using an atomic force microscope (AFM) and / or ellipsometry in the UV / Vis range.

[0286] To produce a surface having anti-soiling properties and / or anti-fogging properties, the inverse cones of an interference pixel according to a preferred embodiment of the present invention have a mean structural depth or profile depth on average d5o in the range from 0.05 pm to 20 pm, particularly preferably in the range from 0.05 pm to 10 pm, very particularly preferably from 0.05 pm to 5 pm, in particular from 0.05 pm to 2 pm, more preferably in the range from 0.1 pm to 1 pm, very particularly preferably from 0.5 pm to 800 nm. The structural depth of the inverse cones of an interference pixel is generally described by the mean structural depth (d5o), which defines the proportions of cones within an interference pixel with a certain structural depth smaller or larger than the specified value for the structural depth.

[0287] The shallow structural depths advantageously enable the preservation of the optical properties, in particular the original transparency of the unstructured substrate, since the introduced periodic dot structures do not have a "disturbing" effect due to the shallow structural depth. The transparency of the structured substrate differs from the unstructured substrate of the same structure by a maximum of 10%, preferably by a maximum of 5% or 2%, with the transparency of the structured substrate preferably being lower than that of the unstructured substrate of the same material and structure. In particular, these shallow structural depths can be generated by single irradiation using a laser pulse with low laser pulse energy.

[0288] Furthermore, these structural depths are characterized by the fact that the lateral surface of the pegs or inverse pegs, as when utilizing the trap effect, serves as a mirror surface, preferably a quasi-homogeneous mirror surface, which reflects the portion of reflected incident electromagnetic radiation within the pegs and / or inverse pegs, in particular inverse pegs, up to the saddle point, wherein at each further reflection point within the lateral surface, a portion of (remaining) electromagnetic radiation is coupled into the substrate, the outer surface and / or inner surface of which is formed from such a structured and an unstructured region (see, for example, Figs. 4 to 6). According to a preferred embodiment of the invention, the lateral surface of the pegs or inverse pegs is smooth.

[0289] Due to the two aforementioned advantages, the periodic structures defined herein in conjunction with anti-dirt properties and / or anti-fogging properties are particularly suitable for application to the outer surface of a cover layer of an optoelectronic component.

[0290] For the purposes of the invention, a structured substrate, e.g., a cover layer with anti-dirt properties and / or anti-fogging properties, also describes such a substrate having a structured region consisting of superimposed structures, i.e., a further structure being superimposed on the first periodic dot structure, preferably at least one structure having dimensions in the submicrometer range, and preferably at least one structure being formed from cones or inverse cones (as defined herein), which can be generated in particular by interfering laser beams. Preferably, the further structure is a line structure or a further periodic dot structure composed of cones or inverse cones.

[0291] Interference period

[0292] In particular, the structured region is a dot structure of inverse cones with average dimensions in the micrometer or submicrometer range, wherein the structure of an interference pixel in particular has an average distance based on the respective saddle point or midpoint of height of two adjacent cones of an interference pixel of 200 nm to 50 pm, preferably 200 nm to 20 pm, very particularly preferably 200 nm to 10 pm. This dot structure in the micrometer range can have a further structure, preferably in the nanometer range, superimposed on it, wherein the average dimension of the superimposed structure preferably has dimensions in the range of the laser wavelength h, or h / 2, in particular from 100 nm to 1,000 nm, very particularly preferably from 200 nm to 500 nm. For the purposes of the invention, such a structure is also referred to as a hierarchical structure.

[0293] The base area of ​​the inverse cones is preferably 10% to 40% of the interference period of the periodic dot structure.

[0294] The present invention also encompasses a structured substrate (5) with a surface having anti-contamination properties, the surface consisting of a structured and an unstructured region, the structured region being formed by a first periodic dot structure having a first interference period in the micrometer or submicrometer range. The periodic dot structure is formed by inverse pegs, the inverse pegs being periodically arranged at a distance from one another, based on their respective saddle point or height center (circular base area), in the range from 50 nm to 50 pm. A substrate structured in this way is characterized in that it has a periodic dot structure with exactly one interference period. There are no superimposed periodic structures which have a second interference period.This results in a more precise control of the substrate properties, in particular the transparency of the substrate, which is not affected by the structuring due to the shallow structure depths resulting from the fact that each interference pixel is irradiated only once.

[0295] In addition, such a substrate offers good control over the substrate's hydrophilic properties, as a specific water contact angle can be reliably generated at the substrate surface. Such reliable reproducibility of the water contact angle can be achieved by avoiding potentially occurring LIPSS structures by using single irradiation, i.e., a single laser pulse to generate the periodic dot structure. Single irradiation prevents the occurrence of uncontrolled self-organization processes that lead to LIPSS structures, also referred to as quasi-periodic wave structures in the context of the invention.

[0296] LIPSS structures often occur when a dot structure within an interference pixel is irradiated multiple times consecutively, i.e., with multiple pulses. The resulting self-organization processes are difficult to control, which negatively impacts reproducibility.

[0297] Alternatively, a structured substrate with anti-contamination properties can also be formed from a plurality of superimposed, preferably hierarchical structures, comprising at least a first structure with an interference period in the micrometer and / or submicrometer range and a second structure with an interference period in the micrometer and / or submicrometer range, wherein the first structure has interference periods that are significantly larger than those of the second structure, and wherein at least one structure is formed from inverse cones (as defined herein), which can be generated in particular by interfering laser beams. Preferably, the second structure has interference periods with dimensions in the range of 1% to 30%, in particular from 5% to 20%, preferably from 5% to 15% of the dimensions of the interference period of the first dot structure.Hierarchical structures can advantageously further enhance the anti-fouling properties of a substrate, as a higher degree of hydrophilicity or hydrophobicity can be achieved. This is due to the fact that hierarchical structures achieve a significant increase in surface roughness compared to conventional micro- or submicrometer-scale structuring.

[0298] Preferably, the interference period of the first structure, in particular of the periodic dot structure, is in the range from 50 nm to 2 pm, preferably in the range from 100 nm to 1 pm, particularly preferably in the range from 100 nm to 700 nm, very particularly preferably in the range from 200 nm to 500 nm.

[0299] According to a further embodiment, the interference period of the first structure, in particular periodic dot structure, is in the range from 9.5 pm to 50 pm, particularly preferably in the range from 10 pm to 40 pm or 12 pm to 40 pm, very particularly preferably in the range from 15 pm to 30 pm.

[0300] According to a further embodiment, the superimposed structure has a quasi-periodic line structure, wherein the line structure is pronounced as a wave structure, wherein the material on the surface of the substrate in the region of the superimposed structure has a sequence of wave crests and wave troughs whose interference period is in the sub-micrometer range, preferably in the range from 100 nm to 700 nm, particularly preferably in the range from 100 nm to 500 nm, very particularly preferably in the range from 100 nm to 300 nm. For the purposes of the invention, the term quasi-periodic refers to regularly repeating structural features which, however, in contrast to a truly periodic structure, have deviations in the interference period, wherein these deviations, however, lie in a range significantly smaller than the dimensions of the structural features, preferably in the range from 1% to 5% of the dimensions of the structural features.Defects in structural uniformity, ie a missing wave crest or a missing wave trough, are also possible.

[0301] The wave structure is formed during the structuring process, i.e., when laser pulses impinge on the substrate to be structured, particularly as a result of multiple irradiation, as a result of the appearance of a high-intensity region. Structuring occurs through a self-organization process that is stimulated by the at least partial melting of the substrate material by means of laser pulses in a high-intensity region. In particular, the wave structure is generated using laser-induced periodic surface structures (LIPSS), the appearance of these surface structures being coupled to the generation of the periodic dot structures by means of interfering laser beams.This means, in particular, that the quasi-periodic wave structures only occur in the areas of intensity maxima within an interference pixel, especially within the inverse cones of the first periodic dot structure. The proportion of unstructured regions occurring in the intensity minima remains the same with respect to structuring using a simple periodic dot structure.

[0302] According to one embodiment, the hierarchical structures are created by multiple irradiation of the same interference pixel with identical process parameters, whereby the process parameters relate to the pulse energy, pulse duration, and / or the arrangement of optical elements. This advantageously enables structuring that requires a low intensity of the incident laser (partial) beams, thereby preserving the optical elements that are part of the laser structuring device used for structuring.

[0303] According to a further embodiment, the hierarchical structures are generated by single irradiation of the same interference pixel using high-intensity laser (partial) beams. This advantageously enables the planar structuring of a substrate, for example, with anti-fogging properties, using interfering laser beams and utilizing laser-induced periodic surface structures, without incurring long processing times or a large number of successively executed process steps. The invention thus enables the simultaneous generation of hierarchical structures, which can be used in the technical field both in the field of substrates with anti-fogging properties and in the field of self-cleaning, hydrophobic or superhydrophobic or hydrophilic or superhydrophilic substrates, optionally also with anti-icing and / or anti-reflection properties.

[0304] According to a further embodiment, the hierarchical structures are produced by multiple irradiation of the substrate with different process parameters, wherein the process parameters differ in particular in such a way that a second periodic structure with a different interference period is produced. The second periodic structure is a line structure or a point structure, preferably a point structure. In the sense of the invention, a line structure refers to a so-called 1D structure, which consists of parallel structural peaks and structural valleys, which are arranged in a regular sequence of one peak and one valley each. In this embodiment, the second periodic structure is produced analogously to the first periodic point structure by direct laser interference structuring. The interference period of the second periodic structure can be adjusted using the process parameters.The creation of the second periodic structure is not coupled to the creation of the first periodic structure. Therefore, a substrate structured in this way has a smaller proportion of unstructured surface compared to a substrate structured only with a first periodic dot structure, since the unstructured regions of the first periodic dot structure are partially structured during the creation of the second periodic structure with shorter interference periods.

[0305] Preferably, the proportion of the structured area, in particular surface of the substrate, is 5% to 100%, preferably 10% to 70%, particularly preferably 20% to 50% of the total surface of the substrate.

[0306] The inventors have discovered a connection between the surface properties of a substrate and the formation of condensation, particularly in the form of fog or mist, on its surface. In particular, so-called anti-fogging properties can be achieved if the structure size on the surface of a substrate is sufficiently small. Research results have shown that a substrate with superhydrophilic properties can also exhibit anti-fogging properties.

[0307] An optoelectronic component with anti-fogging properties in the sense of the invention describes an optoelectronic component with a cover surface, preferably made of a semi-transparent or transparent substrate, with a periodic dot structure with interference periods in the micrometer or sub-micrometer range, i.e. in the range from 50 nm to 50 pm. These anti-fogging properties arise when the dimensions of the structure produced, i.e. the interference period and dimensions of the individual inverse cones, increase the surface roughness of the substrate in such a way that the hydrophilic properties of the unstructured surface are enhanced in such a way that contact angles in the range from 0° to 20°, preferably 0° to 15°, particularly preferably 0° to 10°, very particularly preferably 0° to 5° are formed upon wetting with water, thus creating a superhydrophilic surface.The increased surface roughness is based on the fact that the surface texture is changed in the micro- or sub-micrometer range by the periodic dot structure introduced into the substrate, in particular on the fact that the surface of the substrate has depressions due to the periodic dot structure introduced.

[0308] According to a further embodiment of the invention, the interference period of the periodic dot structure is in the range from 50 nm to 2 pm, preferably from 100 nm to 1 pm, particularly preferably in the range from 100 nm to 700 nm, and most particularly preferably in the range from 100 nm to 500 nm. The inventors have discovered that antibacterial properties can be detected on the surface of a substrate with interference periods below 2 pm. Advantageously, a substrate structured in this way also exhibits antibacterial, and therefore antiseptic, properties in addition to pronounced anti-fogging properties.

[0309] In a preferred embodiment, the periodic dot structure has dimensions that are significantly larger, at least 10% to 30% larger, than the bacteria depositing on it. This isolates the bacteria depositing on the surface and thus renders them harmless. In a particularly preferred embodiment, the periodic dot structure has dimensions that are significantly smaller, at least 10% to 30% smaller, than the bacteria depositing on it. This prevents the bacteria from adhering to the surface, and the surface is thus kept sterile.

[0310] According to a further embodiment of the invention, the structured substrate has a periodic dot structure formed from cones. The structural properties, such as the interference period and the hydrophilic properties, in particular the water contact angle, which forms on the surface of the substrate upon wetting, are identical to the properties defined herein of a structured substrate having a periodic dot structure, wherein the dot structure is formed from inverse cones. Consequently, what was explained for inverse cones also applies to the structures formed from cones. The periodic dot structure produced in this way, having cones regularly arranged relative to one another, is therefore just as suitable for producing a substrate with anti-fogging properties as the periodic dot structure defined herein having inverse cones. The structural properties remain unchanged.

[0311] Furthermore, the cover layer structured according to the invention is suitable for further processing, for example, chemical and / or physical treatment. Chemical spray coatings and / or sol-gel processes are particularly suitable for enhancing the properties defined herein that are obtained with the structuring according to the invention or for modifying the properties of the structured substrate by applying other layers (e.g., anti-reflective properties and / or hydrophobic or superhydrophobic and / or hydrophilic or superhydrophilic properties).

[0312] Furthermore, the structured substrates can be subsequently modified by etching with acids (e.g., hydrofluoric acid) or by leaching the surface in alkaline solutions. Preferably, selective etching is used. This allows acids or bases to attack preferentially in the generated structural valleys (Z-minima), i.e., in the inverse cones. Furthermore, the degree of etching or the etching speed can be adjusted via the density of the microstructures (the coverage of cones per unit area, which is determined by the number and diameter of the inverse cones).

[0313] In laser interference structuring, the interference maxima or high intensity regions of the interference pattern of several superimposed laser (partial) beams are converted into three-dimensional point structures in the form of inverse cones on a surface of the substrate or in a plane within the volume of the substrate.

[0314] The physical / chemical effects for generating the dot structures only occur above a certain energy threshold, i.e., above a certain intensity threshold. This energy threshold limits the size of the interference pixel, as the intensity of the maxima decreases toward the edges of the superimposed laser (partial) beams. If the intensity at the edges is too weak, no structuring within the meaning of the invention occurs in these areas.

[0315] The interference pattern depends on the properties of the superimposed laser beams. The structure depth can be influenced by the energy input, i.e., by the wavelength of the laser beam. However, the properties of the resulting dot structure when irradiated with a specific pulse length, i.e., the properties of the individual interference pixels, also depend on the properties of the substrate.

[0316] According to a preferred embodiment of the present invention, the application of an interference pixel, for example a first, a second and / or a third interference pixel, to the surface of a substrate by means of laser interference structuring takes place by irradiating the substrate with a plurality of laser (partial) beams at an angle to the surface of the substrate of 45° to 90° (perpendicular), preferably at an angle of 60° to 90°, particularly preferably at an angle of 75° to 90°, for example in each case in an angular range of / to 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 99°, 90°. Most preferably, the application of an interference pixel to the surface of a substrate is carried out substantially perpendicularly along a normal to the surface, ie at an angle of 90° ± 1 °.According to an advantageous embodiment of the invention, the "fakir effect" is created on a surface by targeted roughening of an outer and / or inner surface, preferably an outer surface. The aspect ratio of the first dot structure or a second dot structure or a line structure is preferably at least 0.5, more preferably at least 1.0. According to a preferred embodiment, the aspect ratio is a maximum of 0.1 and in particular only 0.005. This can be achieved, for example, by an interference period of 20 pm and a structure depth of 100 nm. This can advantageously reduce the adhesion of dust particles, in particular desert sand, in particular Kalahari sand.The use of such structures in extraterrestrial areas also offers many advantages. Such structures significantly reduce the adhesion of particles such as those found on the Moon or Mars when the structure sizes are adapted to the average particle sizes. The aspect ratio is the quotient of the structure depth, especially the average structure depth, and the interference period. Because the resulting structures are comparatively deep compared to a given interference period, the contact area is reduced, thus reducing the adhesion of liquids and particles, such as bacteria.

[0317] PROCEDURE

[0318] The present invention also encompasses a method for producing an optoelectronic component according to the invention, in which the outer surface and / or the inner surface of an optoelectronically active layer, a contact layer, and / or a cover layer is formed from a structured and an unstructured region. The corresponding aforementioned layer, preferably a transparent layer, has a periodic dot structure with dimensions in the micrometer and / or submicrometer range, which is preferably produced by mechanical methods, laser structure application methods, and / or by chemical (post-)treatment, in particular by direct laser interference structuring.

[0319] According to the invention, the method for producing an optoelectronic component comprises the following steps:

[0320] A first layer is provided, which encloses the optoelectronic component and has an inner surface, which can also be referred to as the inner side. A functional layer, preferably an optoelectronically active layer or a contacting layer, is applied to at least a partial region of the inner surface of the first enclosing layer. Furthermore, a second layer, which encloses the optoelectronic component, is applied to at least a partial region of the functional layer. The first or the second enclosing layer is designed as a cover layer, having an outer surface and an inner surface, of the optoelectronic component.The outer surface and / or the inner surface of the cover layer is formed from a structured and an unstructured region, or the outer surface and / or the inner surface, preferably the outer surface, of the cover layer is structured following step (c) such that the surface structured in this way is formed from a structured and an unstructured region. The structured regions are preferably produced by means of laser interference structuring. In this case, an optoelectronic component can therefore first be produced, at least one of whose cover layer is then structured, or the structuring of the cover layer can first be carried out, i.e. the creation of the structured and the unstructured region, after which the cover layer thus generated is integrated with a structured and an unstructured region into an optoelectronic component.In any case, the structured region according to the invention leads to an improvement in the properties of the structured surface and thus to an increase in efficiency.

[0321] Furthermore, the invention relates to a method for producing an optoelectronic component which is characterized in particular by anti-reflection properties and / or anti-soiling properties and / or reduced reflection due to the trapping effect and / or an extension of the light path by diffraction at the grating, and comprises the following steps:

[0322] (a) providing a first final layer having an inner surface,

[0323] (b) applying a functional layer, preferably an optoelectronically active layer or a contacting layer, to at least a partial area of ​​the inner surface of the first final layer,

[0324] (c) applying a second final layer to at least a partial region of the functional layer, wherein the first or the second final layer is formed as a cover layer of the optoelectronic component, wherein the functional layer, preferably the optoelectronically active layer or the contacting layer, and / or the cover layer has an outer surface and an inner surface, wherein the outer surface and / or the inner surface of the functional layer, preferably the optoelectronically active layer or the contacting layer, and / or the cover layer are each formed independently of one another from a structured and an unstructured region, or wherein the outer surface and / or the inner surface of the functional layer, preferably the optoelectronically active layer or the contacting layer, and / or the cover layer are each formed independently of one another after the application of the respective layer,in particular immediately after the application of the respective layer (i.e. before the application of the next layer which is used to build up the layer stack), or following step (c) is structured in such a way that it is formed from a structured and an unstructured region, wherein the structured region each independently has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi), wherein the first interference pixel (10) has a periodic lattice of at least three cones or inverse cones, wherein the first interference period of the first periodic dot structure is in the range from 50 nm to 50 pm.,

[0325] According to a preferred embodiment, the first interference period of the first periodic dot structure is in the range from 100 nm to 1,000 nm. This preferably allows the antireflection properties of the substrate, in particular of the optoelectronically active layer, the contacting layer and / or the cover layer (as defined herein) to be adjusted.

[0326] The subsequent structuring of existing components has the great advantage that existing components or optoelectronic modules can also be structured using the method according to the invention, thus improving their optical properties due to improved light coupling or decoupling. An increase in efficiency can therefore also be achieved subsequently using the method according to the invention. Irrespective of this, subsequent structuring, i.e. after application of the respective layer to be structured, e.g. immediately after application of the respective layer or following step (c), offers the advantage that the process step of structuring the layer to be structured can be integrated into the ongoing production process / setup of an optoelectronic component.Structuring can preferably be carried out using laser structure application methods, in particular direct laser interference structuring. This eliminates the need for transport or relocation of the component or individual prefabricated layers. Furthermore, structuring during the ongoing process allows for better coordination of the parameters of the optoelectronic component, in particular of the individual layers of the optoelectronic component. It can be provided that either the outer surface and / or the inner surface and / or within the volume of the functional layer, preferably the optoelectronically active layer or the contacting layer, and / or the cover layer, are each structured independently of one another.

[0327] According to the invention, the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel with a first interference period. The first interference pixel, in turn, has a periodic lattice of at least three, preferably seven, periodically arranged cones or inverse cones. The interference period of the first periodic dot structure lies in the micrometer and / or submicrometer range, preferably in the range from 50 nm to 50 pm, particularly preferably in ranges as defined herein.

[0328] Preferably, the structuring of the surface of a substrate, ie the application of the structured regions comprising a first, second, third and / or further interference pixel, in particular of the optoelectronically active layer, the contacting layer and / or the cover layer, is carried out by a mechanical method, laser structure application method and / or by means of chemical (post-)treatment.

[0329] To produce substrates whose outer surface and / or inner surface is formed from a structured and an unstructured area, lithography, in particular photolithography or imprint lithography, such as nano-imprint lithography, can be used as a mechanical process. In lithography, a sacrificial layer is generally arranged on the surface of the substrate to be structured. The sacrificial layer serves to mask the surface to be structured and can be removed, in particular completely, after lithography. For example, the sacrificial layer can be applied to the surface to be structured and subsequently structured. The lateral structure of the sacrificial layer can then be transferred to the surface of the substrate, in particular by means of an etching process.

[0330] In photolithography, the sacrificial layer is usually a photosensitive resist layer whose chemical properties are locally modified by irradiation through a suitably structured mask, such as a metal mask, allowing the formation of structured regions in the sacrificial layer. This process can achieve structuring of surfaces with feature sizes of a few micrometers in the lateral direction. Both regular and irregular structures can be produced in this way.

[0331] Imprint lithography, e.g., nano-imprint lithography, is a microforming or contact structuring process in which the surface of a substrate, e.g., the sacrificial layer, is structured using a suitably structured mold. This mold, such as a suitably structured stamp, is pressed into the sacrificial layer. The sacrificial layer can, for example, contain a thermoplastic polymer (Thermoplastic Nano Imprint Lithography, T-NIL) or a photosensitive material (Photo Nano Imprint Lithography, P-NIL). Nano-imprint lithography allows surfaces to be structured particularly easily. In particular, particularly small lateral structure sizes, i.e., structures below 1 pm down to the range below 10 nm, can be produced.Nano-imprint lithography is therefore particularly suitable for producing structure sizes that are on the order of the wavelength of radiation in the infrared, visible, or ultraviolet spectral range, for example for producing structures for a photonic grating. Such a method is particularly suitable when the structured regions of the surface of the substrate are to have a periodic dot structure (as defined herein) formed from cones. To produce the mold, it is advisable to apply the negative of the desired periodic dot structure to the substrate of the respective layer of the optoelectronic component, in particular a periodic structure formed from cones, for the indirect application or production of structures on another substrate, e.g.by laser structure application methods, in particular direct laser interference structuring, and transferring this to the substrate surface to be structured. In a preferred embodiment of the invention, the structuring of the substrate surface can be carried out by laser structure application methods, in particular direct laser interference structuring. A periodic intensity distribution is generated on the surface of the substrate or in its volume through interference of pulsed laser beams by splitting the original laser beam into several partial beams and by subsequently superimposing these partial beams at any fixed point (focusing point) on the surface of the substrate or in the volume of the substrate.

[0332] A structured area on an outer or inner surface of a cover layer formed from a substrate can be created as follows:

[0333] A substrate (5), preferably a flat and / or transparent substrate, is provided, which is located on a holding device. A laser beam is emitted from a laser radiation source (1). The laser beam is split by a beam splitter element (2), which can also be referred to as an optical beam splitter element, into at least three, particularly preferably four, partial beams. The partial beams impinge on a focusing element (4), which focuses (bundles) the at least three, particularly preferably four partial beams on the surface or inside the substrate (5), preferably a flat and / or transparent substrate, so that the partial beams interfere constructively and destructively on the surface of the substrate. Thus, a periodic dot structure in the micrometer and / or submicrometer range is produced on the surface of the substrate (5), preferably a flat and / or transparent substrate, by laser interference processing.The at least three partial beams are superimposed in such a way that a 2D pattern is created.

[0334] According to one variant of the method, the periodic dot structure is created within an interference pixel on the outer surface and / or inner surface of the cover layer using a single laser pulse, referred to herein as single irradiation. Single irradiation means that the interference pixel is preferably exposed only once within a processing step using a single laser pulse. Thus, a dot structure with one interference period is created within an interference pixel by exposure to only one laser pulse. Adjacent interference pixels preferably do not overlap, so that a resulting inverse cone is not illuminated again. The maximum laser pulse energy depends on the pixel size and the material. The minimum pulse energy is preferably 200 pJ. This advantageously enables a high process speed.In addition, the use of single irradiation prevents the occurrence of quasi-periodic wave structures, so-called LIPSS, due to uncontrolled self-organization processes, which alter the optical properties of the substrate surface to the extent that transparency and the reproducibility of the water contact angle are impaired. Consequently, the occurrence of LIPSS structures can be prevented by single irradiation. This allows for significantly more precise process control and the reliable generation of a specific property.

[0335] The fact that the periodic dot structure within an interference pixel is generated by applying a single laser pulse using single irradiation also has the advantage that very small structure depths can be created, which is particularly advantageous for thin substrates.

[0336] Preferably, single irradiation produces shallow structural depths that can be adjusted according to the material or material composition of the substrate. For example, structural depths in the range from 0.05 pm to 2 pm, preferably from 0.1 pm to 1 pm, can be achieved in this way. For example, this can also be used to structure substrates that are characterized in particular by anti-reflection properties, with the structural depths being in the range from 5 nm to 200 nm, particularly preferably in the range from 5 nm to 150 nm, and most preferably 10 nm to 100 nm. By using a single laser pulse and by the fact that there is no pulse overlap between neighboring interference pixels, it is ensured that the structural depths of the periodic dot structure are minimal.This advantageously ensures that the optical properties of the substrate, in particular its transparency, are not impaired compared to the unstructured substrate. In particular, the transparency of the structured substrate differs from the unstructured substrate of the same structure by a maximum of 10%, preferably by a maximum of 5% or 2%, with the transparency of the structured substrate preferably being lower than that of the unstructured substrate of the same material and structure.

[0337] According to a further embodiment of the invention, the same interference pixel is processed using multiple irradiation with several consecutive laser pulses. Multiple irradiation means that the same area of ​​the substrate is processed with several consecutive laser pulses. Thus, a dot structure with an interference period within an interference pixel is exposed several times, with a resulting inverse cone being exposed again one or more times. The pulse length is adjustable by the user. In particular, this method processes the same interference pixel using multiple irradiation.Thus, as a result of the successive multiple irradiation, in particular at least three, particularly preferably at least four consecutive pulses with identical process parameters of an interference pixel, a quasi-periodic line structure superimposed on the periodic dot structure forms as a wave structure through self-organization processes. Process parameters, within the meaning of the invention, are understood to mean the setting of the distance between the beam splitter element and the focusing element, the laser pulse duration, the laser pulse energy, the laser wavelength, and / or the position of the interference region on the substrate.

[0338] Self-organization processes refer in particular to so-called LIPSS, as they are known from the state of the art. LIPSS occur as a result of partial heating of the substrate surface and its subsequent solidification in the form of regular, quasi-periodic (as defined herein) wave structures.

[0339] Advantageously, hierarchical structures can be created quickly and effectively on the substrate surface. This eliminates the need for readjustment of the laser interference device and / or reorientation of the substrate. Furthermore, the structural parameters of the periodic dot structure, particularly the structure depth, are also adjustable. A shallow structure depth is preferably achieved by adjusting the process parameters, particularly the laser pulse energy, in such a way that the energy input from the multiple irradiation per interference pixel remains as low as possible.

[0340] In particular, achieving the desired interference periods of the LIPSS generated by the self-assembly processes depends on the material properties of the substrate to be patterned and the properties of the laser beam used for patterning, particularly the wavelength of the laser beam. A desired interference period can therefore be adjusted by selecting the appropriate laser radiation source.

[0341] According to a further embodiment of the invention, a further periodic dot structure or periodic line structure with an interference period different from the interference period of the first periodic dot structure is applied to the substrate by multiple irradiation with different process parameters. The different process parameters relate in particular to the distance between the beam splitter element and the focusing element, which changes the interference period of the further periodic dot structure or line structure compared to the first periodic dot structure. However, an additional change in the laser pulse duration and / or energy is also possible.

[0342] This advantageously allows a flexible second structure with dimensions in the micrometer and / or submicrometer range to be applied to the substrate, which is independent of the first periodic dot structure. This ensures easy alignment of the interference pixels on the substrate. Furthermore, the proportion of the structured area on the substrate surface is increased, allowing certain properties, such as the trapping effect to reduce reflection, to play a greater role.

[0343] The advantage of such a method is that the interference period n can be precisely controlled by adjusting the beam splitter element, and that the desired interference period n can be adjusted independently of material properties and the properties of the laser beam used for structuring.

[0344] By moving the beam splitter element along its optical axis, the interference period or interference period of the respective interference pixel can be continuously adjusted. This allows at least two, but also any number of, additional structurings to be created on the surface of the substrate without further modification of the structure, e.g., without replacing optical elements or moving the substrate. Preferably, the additional optical elements are fixed when setting or changing the specified or desired interference period. This increases both the precision in aligning the structures and the speed of the process compared to conventional methods or devices.

[0345] Preferably, the distance of the optical beam splitter element from the focusing lens according to the method according to the invention is preferably 10 mm to 50 mm or 150 mm to 200 mm.

[0346] The laser pulse duration is preferably 50 fs to 1 ns, particularly preferably 50 fs to 10 ps. This short laser pulse duration can prevent or at least minimize unwanted and / or uncontrolled melting of the substrate (e.g., in the form of a structural or chemical transformation), particularly as a result of local overheating, e.g., due to excessive energy input. This is particularly advantageous for the "sensitive" materials used herein that the substrates comprise or are made of. The laser wavelength is preferably 200 nm to 10.6 pm, more preferably 266 nm to 1064 nm.

[0347] The laser pulse energy is preferably 50 pJ to 20 mJ, more preferably 300 pJ to 800 pJ, and particularly preferably 500 to 800 pJ. This low laser pulse energy per laser pulse can prevent or at least minimize unwanted and / or uncontrolled melting of the substrate (e.g., in the form of a structural or chemical transformation), particularly as a result of local overheating, e.g., due to excessive energy input. This is particularly advantageous for the "sensitive" materials used herein that the substrates comprise or are made of.

[0348] The present invention also relates to a method for producing an optoelectronic component by means of laser interference structuring, in particular by a method disclosed herein, comprising the following steps: a) providing a cover layer or a substrate (5), preferably comprising a transparent material, b) applying at least one first interference pixel (10) with a first interference period (pi) to an outer or an inner surface of the cover layer, in particular by means of laser ablation, c) applying at least one second interference pixel (11) with a second interference period (p2) to the surface of the cover layer processed in step b), in particular by means of laser ablation, wherein the first and the second interference pixel each independently of one another form a periodic grating of at least three inverse cones with a first interference period (pi) ora second interference period (p2), wherein the dot structure is formed by superimposed application of the second interference pixel (11) with the first interference pixel (10) within a plane on a surface or in the volume of the substrate, wherein the ratio of the first interference period (pi) to the second interference period (p2) is in the range from 20:1 to 1:20, preferably in the range from 10:1 to 1:10, particularly preferably in the range from 5:1 to 1:5, in particular 3:1 to 1:3. Particularly advantageously, this makes it possible to produce a structuring which has anti-glare properties on the substrate, in particular on an at least partially transparent cover layer of an optoelectronic component.

[0349] For the purposes of the invention, glare is the reflection of light from a light source (e.g. the sun) on a transparent substrate, e.g. a window or a screen, which can make it difficult to see what is happening on the screen.

[0350] These glare effects can be reduced with the help of an anti-glare surface treatment (typically achieved through coatings in the prior art). An anti-glare structure scatters incident light on the surface, significantly reducing reflections.

[0351] According to a preferred embodiment of the invention, the interference periods of the dot structure of the first interference pixel and the period of the second interference pixel are identical.

[0352] According to a preferred embodiment of the present invention, the method according to step c) comprises applying at least one further type of interference pixel with a further interference period (p n ), for example a third interference pixel (12) with a third interference period (p3) onto the surface of the cover layer processed in steps b) and c), in particular the surface of the substrate (5), in particular by means of laser ablation, wherein the further, for example the third interference pixel (12) is arranged superimposed on the first interference pixel (10) and second interference pixel (11) according to the features defined herein. The ratio of the further interference period (p n) to the other interference periods preferably in the range from 20:1 to 1:20, preferably in the range from 10:1 to 1:10, particularly preferably in the range from 5:1 to 1:5, in particular 3:1 to 1:3, whereby the properties defined herein, in particular the anti-glare properties or the reduction of reflection due to the trap effect of the cover layer, can be optimized.

[0353] According to a further development of the procedure, the procedure additionally includes the following steps:

[0354] • Providing a further, i.e. second, substrate, wherein the second substrate is preferably transparent, and

[0355] • Embossing the first substrate onto the other substrate, creating a periodic dot structure on the second substrate, which consists of studs. The first substrate is used as a negative mold for the second substrate. Advantageously, the first substrate can thus be used to emboss any number of additional substrates, which can significantly accelerate the process of creating a structured substrate with anti-fogging properties.

[0356] According to a preferred embodiment, for applying a periodic structure to a substrate, the periodic dot structure is first produced on a negative mold by means of a laser interference method (as defined herein) and applied by means of the negative mold to the substrate to be structured, in particular the functional layer, such as the optoelectronically active layer or the contacting layer, or the cover layer, for example by means of imprint lithography methods, such as nanoimprint lithography.

[0357] The inventors of the present invention have further discovered that, in addition to the periodicity, the structural depth (i.e., the depth of the inverse cones, measured from their saddle point of the depression to the apex) also influences the properties, in particular the optical properties or the wetting properties, for example, the anti-reflection properties (as defined herein). For example, the structural depth or profile depth of the inverse cones (elevations and depressions) is, on average, in the range from 0.05 pm to 2 pm, preferably in the range from 0.1 pm to 1 pm.

[0358] Preferably, a device for producing a structured substrate (5), preferably a flat and / or transparent substrate, is used, which device comprises two deflection elements (6), (7). The deflection elements (6), (7) are arranged in the beam path (3) of the laser between the beam splitter element (2) and the focusing element (4). The deflection elements (6), (7) serve to widen the diffraction angle of the at least three, particularly preferably four, partial beams by interfering on the surface or in the interior of the substrate (5), preferably a flat and / or transparent substrate. By adjusting the distances between the optical elements, it can be ensured that only the beam splitter element (2) needs to be movable along its optical axis to change the interference period. This enables easier adjustment processes during processing.

[0359] In a preferred embodiment, a device for producing a structured substrate, preferably a flat and / or transparent substrate, is used, which uses a pulsed laser radiation source (1). In a particularly preferred embodiment, a device for producing a structured substrate, preferably a flat and / or transparent substrate, is used, which has a holding device for the substrate that is freely movable in the xy plane, perpendicular to the beam path (3) of the laser beam emitted by the laser radiation source (1).

[0360] The pixel density Pd, i.e. the distance at which an interference pixel with the width D can be applied to the substrate, preferably a flat and / or transparent substrate, can be adjusted by means of the frequency of the laser radiation source (1), f, and the speed of movement of the holding device, v, to: p d = V / f

[0361] If the width of the interference pixel, D, is greater than the pixel density Pd, neighboring interference pixels overlap in a region. This region is known to those skilled in the art as the pulse overlap, OV. It can be calculated as:

[0362] OV = ^ D ~ Pd D

[0363] In a preferred embodiment, in the method for producing a structured substrate, preferably a flat and / or transparent substrate, Pd is smaller than D. The resulting pulse overlap OV leads to multiple irradiation of the substrate, preferably a flat and / or transparent substrate. This preferably allows non-textured surfaces to be avoided.

[0364] In a particularly preferred embodiment, the method for producing a structured substrate, preferably a flat and / or transparent substrate, involves irradiating the same interference pixels multiple times. This makes it possible to increase the depth of the resulting microstructures.

[0365] The advantage of a structured substrate produced by such a method, preferably a flat and / or transparent substrate, is the high regularity of the generated periodic dot structures with structural dimensions in the micrometer and / or submicrometer range. A periodic dot structure produced in this way with dimensions in the micrometer and / or submicrometer range preferably has a coefficient of variation (a value resulting from dividing the standard deviation by the average value) of the stud cross-section of 15% or less, more preferably 10% or less, and even more preferably 5% or less.

[0366] In particular, multiple irradiation of a substrate is suitable for producing hierarchical structures. Thus, multiple irradiation of the same interference pixel causes at least partial melting of the substrate material, whereby a wave structure forms during the structuring process, i.e., upon impact of a laser pulse, as a result of the occurrence of a high-intensity region. The structuring, in particular the wave structure, forms through a self-organization process. In particular, the wave structure superimposes a periodic dot structure in the micrometer or submicrometer range, which can be produced by laser interference structuring. Thus, a hierarchical structuring can be produced in a substrate in a single process step.According to a preferred embodiment of the invention, multiple irradiation, preferably 2-fold to 400-fold, in particular 20-fold to 300-fold, particularly preferably 50-fold to 200-fold irradiation of the same interference pixel on the substrate, thereby forming a wave structure (as defined herein), in particular a periodic dot structure composed of superimposed structures, wherein at least one structure has dimensions in the submicrometer range, in particular a quasi-periodic wave structure, and wherein at least one structure is formed from inverse cones. The time offset between the individual pulses is particularly preferably in the range of the pulse duration of the laser pulse, preferably in the range from 50 fs to 1 ns, particularly preferably in the range from 10 fs to 50 ps, ​​very particularly preferably in the range from 10 fs to 10 ps.

[0367] Hierarchical structuring refers to a structure in which a first structure with dimensions in the micrometer or submicrometer range, which corresponds to an interference pattern, is superimposed by a further structure having dimensions that are smaller than the dimensions of the first structure and which is formed by a self-organization process or a further laser interference process. Preferably, the dimensions of the further structure, which is formed by a self-organization process or a further laser interference process, are in the range of 1% to 30% of the dimensions of the first structure, which corresponds to an interference pattern.

[0368] In addition, the method defined herein makes it possible to provide a substrate with hierarchical structures using the same device and, moreover, in the same process step. Conventional processes proceed successively, i.e., they are not capable of simultaneously producing a first structure with dimensions in the micrometer or submicrometer range, corresponding to an interference pattern, and a further structure formed by a self-organization process. Displacing the substrate to be structured, preferably a flat and / or transparent substrate, in the laser beam is comparatively complex and slow due to the relatively large masses moved.It is therefore advantageous to keep the substrate, preferably a flat and / or transparent substrate, stationary during processing, and to achieve the planar structuring of the substrate by focusing the partial beams onto the surface or volume of the substrate by manipulating the laser partial beams with optical elements (focusing mirrors or galvo mirrors (laser scanners)) in the beam direction. Since the masses moved are relatively small, this can be achieved with far less effort and much more quickly. The substrate is preferably stationary during the process.

[0369] The planar structuring of the substrate is of course also possible by moving the substrate in the laser beam.

[0370] The invention also relates to a method for producing an optoelectronic component which is characterized in particular by anti-reflection properties, reduced reflection due to the trapping effect and / or an extension of the light path by diffraction at the grating, and comprises the following steps:

[0371] (a) providing a first final layer having an inner surface,

[0372] (b) applying a functional layer, preferably an optoelectronically active layer or a contacting layer, to at least a partial area of ​​the inner surface of the first final layer,

[0373] (c) applying a second final layer to at least a partial region of the functional layer, wherein the first or the second final layer is formed as a cover layer of the optoelectronic component, wherein the volume, in particular a plane within the volume, of the functional layer, preferably of the optoelectronically active layer or the contacting layer, and / or of the cover layer is each independently formed from a structured and an unstructured region, or wherein the volume, in particular a plane within the volume, of the functional layer, preferably of the optoelectronically active layer or the contacting layer, and / or of the cover layer is each independently structured in step (c) such that it is formed from a structured and an unstructured region, wherein the structured region each independently has a first periodic dot structure,wherein the first dot structure is formed from at least one first interference pixel having a first interference period (pi), wherein the first interference pixel has a periodic grating of at least three cones or inverse cones, wherein the first interference period of the first periodic dot structure is in the range from 50 nm to 50 pm.,

[0374] According to a preferred embodiment, the first interference period of the first periodic dot structure is in the range from 100 nm to 1,000 nm. This preferably allows the antireflection properties of the substrate, in particular of the optoelectronically active layer, the contacting layer and / or the cover layer (as defined herein) to be adjusted.

[0375] An optoelectronic component produced by the method and device disclosed herein is also suitable for further processing by means of a coating process, wherein the optoelectronic component can receive a physical and / or chemical coating. Such a coating can enhance the properties of the structured substrate, for example, the anti-reflection properties and / or hydrophilic and / or hydrophobic properties. Application of a chemical spray coating and / or application of a coating by means of chemical vapor deposition and / or sputtering is conceivable.

[0376] The invention thus also encompasses a method in which the optoelectronic component is coated after structuring according to one of the coating types mentioned herein. As a result, the structuring, in particular the first periodic dot structure, then occurs both in the coating and in the underlying cover layer.

[0377] DEVICE

[0378] Laser radiation source (1)

[0379] The device for producing a structured substrate with anti-fogging properties comprises a laser radiation source (1) that emits a laser beam. The radiation profile of the emitted laser beam corresponds either to a Gaussian profile or a top-hat profile, particularly preferably a top-hat profile. The top-hat profile is useful for more homogeneously structuring or covering a surface to be structured or the volume of a substrate and, if necessary, for enabling a faster structuring rate.

[0380] In a particularly preferred embodiment, the laser radiation source (1) is a source that generates a pulsed laser beam. The pulse width of the pulsed laser radiation source is, for example, in the range from 50 fs to 1 ns, in particular 50 fs to 100 ns, most preferably 50 femtoseconds to 10 ps.

[0381] Unless explicitly stated otherwise, laser beam or partial beam does not mean an idealized beam of geometric optics, but a real light beam, such as a laser beam, which does not have an infinitesimally small, but rather an extended beam cross-section (Gaussian distribution profile or an intrinsic top-hat beam).

[0382] A top-hat profile or top-hat intensity distribution refers to an intensity distribution that can be described, at least with respect to one direction, essentially by a rectangular function (rect (x)). Real intensity distributions that exhibit deviations from a rectangular function in the percentage range or inclined flanks are also referred to as a top-hat distribution or top-hat profile. Methods and devices for generating a top-hat profile are well known to those skilled in the art and are described, for example, in EP 2 663 892. Optical elements for transforming the intensity profile of a laser beam are also known.For example, using diffractive and / or refractive optics, laser beams with a Gaussian intensity profile can be transformed into laser beams that exhibit a top-hat-shaped intensity profile in one or more defined planes, such as a Gauss-to-Top Hat Focus Beam Shaper from TOPAG Lasertechnik GmbH, see, for example, DE102010005774A1. Such laser beams with top-hat-shaped intensity profiles are particularly attractive for laser material processing, especially when using laser pulses shorter than 50 ps, ​​since the essentially constant energy or power density allows for particularly good and reproducible processing results.

[0383] The laser radiation source (1) contained in the device according to the invention can have an intensity of 50 pJ to 20 mJ, particularly preferably 300 pJ to 800 pJ. The device according to the invention allows the intensity of the laser radiation source to be flexibly selected within a range. The beam diameter plays no role in generating the interference pattern on the substrate, preferably a flat and / or transparent substrate. Due to the preferred arrangement of the optical elements in the beam path of the laser, no unit for controlling the intensity of the laser beam is necessary.

[0384] The laser radiation source is preferably configured to emit wavelengths in the range from 100 nm to 15 pm (e.g., CO2 lasers in the range from 10.6 pm), most preferably in the range from 266 nm to 1,064 nm. Suitable laser radiation sources include, for example, UV laser beam sources (155 nm to 355 nm), laser beam sources that emit green light (532 nm), diode lasers (typically 800 nm to 1,000 nm), or laser beam sources that emit radiation in the near infrared (typically 1,064 nm), in particular with a wavelength in the range from 200 nm to 650 nm. Lasers suitable for microprocessing are known to the person skilled in the art and include, for example, HeNe lasers, HeAg lasers (approx. 224 nm), NeCu lasers (approx. 249 nm), Nd:YAG lasers (approx. 355 nm), YAG lasers (approx. 532 nm), InGaN lasers (approx. 532 nm).

[0385] According to a further embodiment, the device according to the invention comprises at least one further laser radiation source configured to generate a laser beam that interferes with the laser beam of the first laser radiation source, or with the laser beam of the first laser radiation source split into partial beams, in an interference region. The further laser radiation source has the same properties as described above, which may be the same as or different from those of the first laser radiation source.

[0386] Optical elements

[0387] The present invention encompasses a variety of optical elements. These elements are primarily prisms and lenses.

[0388] These lenses can be refractive or diffractive. Spherical, aspherical, or cylindrical lenses can be used. In a preferred embodiment, cylindrical lenses are used. This makes it possible to compress the overlapping regions of the partial beams (also referred to herein as interference pixels) in one spatial direction and stretch them in another. If the lenses are not spherical / aspherical but cylindrical, this has the advantage that the beams can be deformed simultaneously. This allows the processing spot (i.e., the interference pattern generated on the substrate) to be deformed from a point to a line containing the interference pattern. With sufficient laser energy, this line can be in the range of 10–15 mm long (and approximately 100 pm thick). Furthermore, spatial light modulators (SLMs) can be used for beam shaping.The use of SLMs for spatial modulation of the phase or intensity, or the phase and intensity of an incident light beam, is known to those skilled in the art. The use of liquid crystal on silicon (LCoS) SLMs for beam splitting is described in the literature and is also conceivable in the device according to the invention. Furthermore, SLMs can also be used to focus the partial beams on the substrate. Such an SLM can be controlled optically, electronically, or acoustically.

[0389] All optical elements explained below are arranged in the beam path (3) of the laser. For the purposes of the invention, the beam path of the laser refers to the path of both the laser beam emitted by the laser radiation source and the path of the partial beams split by a beam splitter element. However, the optical axis of the beam path (3) is understood to be the optical axis of the laser beam emitted by the laser radiation source (1). Unless otherwise stated, all optical elements are arranged perpendicular to the optical axis of the beam path (3).

[0390] Beam splitter element (2)

[0391] A beam splitter element (2) is located in the beam path (3) of the laser, behind the laser radiation source (1). The beam splitter element (2) can be a diffractive or a refractive beam splitter element. Diffractive beam splitter elements are also referred to simply as a diffractive optical element (DOE). For the purposes of the invention, a diffractive beam splitter element refers to an optical element containing micro- or nanostructures, preferably microstructures, which split an input beam into different beams according to the different orders of diffraction. For the purposes of the invention, a refractive beam splitter element refers to a beam splitter element in which the beams are split due to differences in refractive indices at surfaces, these being generally transparent optical elements, such as a prism or a double prism.Preferably, the beam splitter element (2) is a refractive beam splitter element.

[0392] According to a preferred embodiment, the beam splitter element is a single optical element, in particular a diffractive or refractive optical element, which is constructed in such a way that the division of the incident laser beam is based on the optical properties of the beam splitter element. This advantageously ensures that a simple optical structure can be realized compared to a multi-part beam splitter element consisting of several optical elements (e.g. mirrors, prisms, etc.). The desired beam splitting can be achieved without calibrating or adjusting the arrangement of several optical elements to one another. The mobility of the beam splitter element in the beam is also very easy to realize, since only a single optical element needs to be moved. In addition, the use of a one-piece beam splitter element results in fewer components that are susceptible to wear and tear, which may otherwise be necessary.are to be exchanged.

[0393] According to one possible embodiment, the beam splitter is designed as a polarizing beam splitter, in which one of the resulting beams has a different polarization than the other, or as a non-polarizing beam splitter, in which the polarization plays no role in the splitting of the beam.

[0394] In a preferred embodiment, the beam splitter element (2) splits the emitted laser beam into at least 3, preferably at least 4, in particular 4 to 8, i.e. 4, 5, 6, 7, or 8 partial beams.

[0395] In a further embodiment, the beam splitter element (2) divides the emitted laser beam into at least 2, preferably at least 3 to 4, in particular 4 to 10, i.e. 4, 5, 6, 7, 8, 9 or 10 partial beams.

[0396] The beam splitter element (2) is freely movable along its optical axis. This means that it can be moved along its optical axis toward or away from the laser radiation source. The movement of the beam splitter element (2) changes the expansion of the at least three partial beams, so that they impinge on a focusing element at different distances from one another. This allows the angle θ at which the partial beams impinge on the substrate (5), preferably a flat and / or transparent substrate, to be changed. Thus, a superposition of four partial beams results in a seamless change in the interference period p. n to where is the wavelength of the emitted laser beam.

[0397] According to a preferred embodiment of the present invention, the beam splitter element is designed as a rotating element. This advantageously allows the polarization of the partial beams to be modified. Particularly preferably, the angle θ at which the partial beams impinge on the substrate (5), preferably a flat and / or transparent substrate, is between 0.1° and 90°.

[0398] The angle 9 also depends on the distances between the optical elements, in particular on the distance between the optical elements and the beam splitter element, and very particularly on the distance between the focusing element and the beam splitter element. Depending on the desired interference period to be generated on or in the flat and / or transparent substrate, the position of the beam splitter element can be adjusted or calculated such that the desired interference period is adjustable. The position of the optical elements comprised by the device, in particular the position of the focusing element, is taken into account in relation to the beam splitter element in such a way that, given a greater or smaller distance between the optical elements, the position of the beam splitter element can be adjusted accordingly.

[0399] In order to generate a structured substrate with anti-fogging properties, it has proven particularly advantageous if a distance from the beam splitter element (2) to the deflection element (7) of 10 mm to 50 mm or 150 mm to 200 mm is set.

[0400] According to a preferred embodiment of the invention, the device also comprises a measuring device, in particular a measuring device which operates by means of a laser or an optical sensor, which is designed to measure the position of the beam splitter element and, if appropriate, the distance of the beam splitter element to the other optical elements, in particular to the position of the focusing element.

[0401] Furthermore, the device according to the invention can comprise a control device which is connected to the measuring device by means of signals and which is in particular connected to a computing unit in such a way with which the measured position of the beam splitter element can be compared with a first predetermined comparison value, wherein the control device is programmed in such a way that, if the distance of the beam splitter element to the further optical elements, in particular to the position of the focusing element and / or the deflecting element (7) is greater or smaller than the first predetermined comparison value, then a control signal is generated via the control device with which at least one position of an optical element, in particular of the

[0402] The beam splitter element (2) is changed, in particular the beam splitter element (2) in relation to the deflection element (7), such that the desired interference period is generated on the substrate. In this context, the method for producing a substrate with a dot structure in the micrometer or submicrometer range can also comprise the following steps, in particular after step (a):

[0403] (i) measuring the position of the beam splitter element (2) and, if appropriate, the distance of the beam splitter element to the further optical elements or to at least one of the further optical elements, in particular to the position of the focusing element (4) and / or the deflecting element (7),

[0404] (ii) comparing the measured position of the beam splitter element with a first predetermined comparison value and,

[0405] (iii) if the measured distance of the beam splitter element to the further optical elements or to at least one of the further optical elements, in particular to the position of the focusing element (4) and / or the deflecting element (7), is greater or smaller than the first predetermined comparison value: changing the position of the optical element, in particular of the beam splitter element (2) in such a way (in particular in relation to the other optical elements, particularly preferably of the beam splitter element (2) in relation to the deflecting element (7)) that the desired interference period is generated on the substrate.

[0406] The laser beam can be divided in the beam splitter element (2) either by a partially reflective beam splitter element, for example a semi-transparent mirror, or by a transmissive beam splitter element, for example a dichroic prism.

[0407] In a preferred embodiment, further beam splitter elements are arranged downstream of the beam splitter element (2) in the laser beam path. These beam splitter elements are arranged such that they split each of the at least three partial beams into at least two further partial beams. This allows a larger number of partial beams to be generated, which are directed onto the substrate, preferably a flat and / or transparent substrate, so that they interfere on the surface or inside the substrate. This allows the interference period of the interference pattern to be adjusted.

[0408] Focusing element (4)

[0409] Furthermore, a focusing element (4) is arranged downstream of the beam splitter element (2) in the beam path (3) of the laser. This focusing element is configured such that the partial beams pass through it in such a way that the partial beams interfere in an interference region on the surface or in the volume of a substrate (5) to be structured. The focusing element (4) focuses the at least three partial beams in one spatial direction without focusing the at least three partial beams in the spatial direction perpendicular thereto.

[0410] For example, the focusing element (4) can be a focusing optical lens. Focusing, in the context of the invention, means bundling the at least three partial beams onto the surface or within the volume of a substrate, preferably a flat and / or transparent substrate.

[0411] The focusing element (4) can be freely movable in the beam path (3). According to a preferred embodiment of the present invention, the focusing element (4) is fixed in the beam path or along the optical axis.

[0412] It is understood that the optical elements defined herein can be arranged in a common housing, for example for beam splitting and for aligning the partial beams in the direction of a substrate to be structured accordingly.

[0413] In a preferred embodiment, the focusing element (4) is a spherical lens. The spherical lens is configured such that the at least three incident partial beams pass through it in such a way that they interfere in an interference region on the surface or in the volume of the substrate (5) to be structured, preferably a flat and / or transparent substrate. The width of the interference region is preferably 1 pm to 600 pm, particularly preferably 10 pm to 400 pm, and most preferably 20 pm to 200 pm. This simultaneously allows a high structuring rate, for example as defined herein, to be set.

[0414] In a particularly preferred embodiment, the focusing element (4) is a cylindrical lens. The cylindrical lens is configured such that the region in which the at least three partial beams overlap on the surface or inside the substrate (5), preferably a flat and / or transparent substrate, is stretched in one spatial direction. As a result, the region of the substrate on which the interference pattern can be generated assumes an elliptical shape. The semi-major axis of this ellipse can reach a length of 20 pm to 15 mm. This increases the area that can be structured during one irradiation.

[0415] First deflection element (7)

[0416] In a particularly preferred embodiment, a deflection element (7) is arranged upstream of the focusing element (4) and downstream of the beam splitter element (2), which deflection element is preferably arranged in the beam path (3) of the laser. This deflection element (7) is used to widen the distances between the at least three partial beams and can thus also change the angle at which the partial beams impinge on the substrate (5), preferably a flat and / or transparent substrate. It is designed such that it increases the divergence of the at least three partial beams and thus moves the region in which the at least three partial beams interfere away from the laser radiation source (1) along the optical axis of the beam path (3).

[0417] In the context of the invention, widening the distances between the at least three partial beams means that the angle of the respective partial beams to the optical axis of the laser beam emitted by the laser radiation source (1) increases.

[0418] The expansion and resulting deflection of the partial beams has the advantage that the partial beams can be more tightly focused by the focusing element (4). This results in a higher intensity in the area where the at least three partial beams interfere on the surface or in the volume of the substrate (5), preferably a flat and / or transparent substrate.

[0419] By appropriately selecting the deflecting element, a unit for controlling the intensity of the laser beam can be dispensed with. In a preferred embodiment of the device, a deflecting element (7) is used which, by expanding the at least three partial beams, allows the at least three partial beams to be focused on the substrate (5) by means of a focusing element (4), wherein the intensity of the interference points on the surface or in the volume of the substrate, preferably a flat and / or transparent substrate, can be achieved without additional adjustment of the intensity of the laser radiation source (1). This has the advantage that laser radiation sources with low intensity (power per area) can also be used to structure the substrate and create the periodic point structure, whereby the optical elements are protected from wear and shallow structure depths are easier to create.

[0420] Additional deflection element (6)

[0421] Furthermore, it can be provided that a further deflection element (6) is arranged downstream of the beam splitter element (3) in the beam path (3) of the laser radiation source (1), which deflects the partial beams such that they run essentially parallel to one another after exiting the further deflection element (6). As a result, the device can be configured such that the processing point, i.e., the point at which the at least three partial beams interfere on the surface or inside the substrate, preferably a flat and / or transparent substrate, remains constant when the beam splitter element is displaced in the beam path of the laser along its optical axis.In the context of this document, the term “essentially parallel” is to be understood as meaning an angular offset of between +15° and -15°, in particular only between +10° and -10°, very particularly preferably between +5° and -5° between the two partial beams, but in particular of course no angular offset, i.e. 0°.

[0422] The further deflection element (6) can be a conventional refractive lens. Alternatively, the further deflection element (6) can also be designed as a diffractive lens (e.g., a Fresnel lens). Diffractive lenses have the advantage of being significantly thinner and lighter, which simplifies miniaturization of the device disclosed herein.

[0423] By appropriately selecting the refractive indices of the optical elements (4), (6) and (7), the distances between optical elements and substrate, as well as the interference period (p n). All optical elements with the exception of the beam splitter element (2) can preferably be fixed within the beam path (3) of the laser. This particularly preferred embodiment therefore offers the advantage that only one element, namely the beam splitter element (2), needs to be moved to adjust the interference range or the interference angle. This eliminates work steps when setting up the device, such as calibrating the device to the desired interference period. Furthermore, a fixed setting of the optical elements, ie wherein preferably all optical elements are fixed within the beam path (3) of the laser, prevents wear on the optical elements.

[0424] Polarization element (8)

[0425] In a further embodiment, a polarization element (8) is located behind the deflection element, particularly preferably in a configuration with two deflection elements (6), (7) behind the further deflection element (6), and in front of the focusing element (4) in at least one of the beam paths of the at least three partial beams. The polarization elements can modify the polarization of the partial beams relative to one another. This allows the resulting interference pattern, which the at least three partial beams image on the surface or in the volume of a substrate, preferably a flat and / or transparent substrate, to be modified.By arranging a polarization element (8) in at least one of the beam paths of the partial beams, preferably not in every beam path of the partial beams, preferably in one beam path to (n-1) beam paths, where n is the number of partial beams generated in the application process, the polarization plane of at least one partial beam in the beam path can advantageously be rotated and thus the pattern of an interference pixel in the plane of the substrate can be "disturbed".

[0426] In particular, the interfering partial beams can be unpolarized, linearly polarized, circularly polarized, elliptically polarized, radially polarized or azimuthally polarized.

[0427] Optical element for beam shaping

[0428] In a further embodiment, the laser radiation source (1) has a radiation profile that corresponds to a Gaussian profile, as described above. In such an embodiment, a further optical element for beam shaping can be located behind the laser radiation source (1) and in front of the beam splitter element (2). This element serves to adapt the radiation profile of the laser radiation source to a top-hat profile.

[0429] The device according to the invention can also include an optical element with a concave-parabolic or planar reflecting surface, wherein the optical element is designed, for example, to be rotatable about at least one axis or displaceable along the beam path (3). This may make it possible to dispense with an additional focusing element (4) or a further deflecting element (6) positioned in the beam path (3). For example, this optical element can be used to direct laser beams or partial laser beams onto the surface of the focusing element (4) or another focusing optical element before the beams reach the substrate to be structured to form structural elements.

[0430] Alternatively, at least one optical element with a concave parabolic or planar reflecting surface can be provided, which is designed, for example, to be rotatable about at least one axis or displaceable along the beam path (3), wherein this optical element is positioned downstream of the first deflecting element (7) and the further deflecting element (6) in the beam path. For example, the partial beams can be deflected in the beam path (deflecting mirror) or focused in the beam path such that the substrate to be structured can be stationary during processing (so-called focusing mirror or galvo mirror (laser scanner) (9)).

[0431] An embodiment comprising a polygon scanner is also conceivable. In this embodiment, at least one optical element comprises a periodically rotating prism, preferably a periodically rotating mirror prism, in particular a polygon mirror or polygon wheel, as well as a focusing element (4) arranged downstream of the periodically rotating prism in the beam path. The focusing element is configured such that the partial beams pass through it in such a way that the partial beams interfere in an interference region on the surface or inside a substrate (5) to be structured. In a preferred embodiment, the optical element further comprises at least one further deflecting element, for example a reflective deflecting element for deflecting the partial beams in the beam path. The at least one further deflecting element can be arranged upstream and / or downstream of the periodically rotating prism in the beam path.The at least one further deflection element is arranged upstream of the focusing element in the beam path.

[0432] Such a setup advantageously allows the rapid scanning of a substrate surface, so that a high structuring rate of up to 3 m 2 / min, especially in the range from 0.05 to 2 m 2 / min, particularly preferably in the range of 0.1 to 1 m 2 / min, most preferably in the range of 0.1 m 2 / min up to 0.9 m 2 / min is achievable. The exact structuring rate depends primarily on the available laser power. With future technologies that offer higher laser power, even higher structuring rates can be achieved.

[0433] Holding device for the substrate

[0434] In a further embodiment, the substrate (5), preferably a flat and / or transparent substrate, is movable in the xy plane. By moving the substrate (5), preferably a flat and / or transparent substrate, in the xy plane, planar processing by means of laser interference structuring can be ensured. In this case, in each processing step (i.e. laser pulse that strikes the substrate to be structured), an interference pixel (as defined herein) is generated which has a size D depending on the angle of incidence and the intensity distribution of the laser beam, as well as the focusing properties of the optical elements. The distance between the various interference pixels, the pixel density Pd, is determined by the repetition rate of the laser radiation source (1) and the movement of the substrate in relation to the focusing point of the optical elements, i.e. the point at which the interference region is generated on the surface or inside the substrate.If the pixel density Pd is smaller than the size of the interference pixels D, a flat, homogeneous processing is possible.

[0435] By moving the substrate in relation to the focusing point (which generates the interference pixel) in combination with pulsed laser (partial) beams, a planar, optionally homogeneous and periodic, point structure can be generated on the surface or in the volume of a substrate, preferably a planar and / or transparent substrate.

[0436] As an alternative to moving the substrate relative to the focus point, the focus point can also be moved over the sample or substrate (e.g. using scanner-based methods).

[0437] Displacing the substrate to be structured, preferably a flat and / or transparent substrate, in the laser beam can be comparatively complex and slow due to the relatively large masses moved. It is therefore advantageous to keep the substrate, preferably a flat and / or transparent substrate, stationary during processing and to achieve the flat structuring of the substrate by focusing the partial beams on the surface or in the volume of the substrate by manipulating the partial laser beams with optical elements (focusing mirrors or galvo mirrors (laser scanners)) in the beam direction. Since the masses moved are relatively small, this can be achieved with far less effort and much more quickly. The substrate is preferably arranged in a stationary manner during the process.

[0438] USE

[0439] A further aspect of the invention relates to the use of a substrate defined herein, in particular an optoelectronically active layer, a contacting layer or a cover layer, whose outer surface and / or inner surface is formed from a structured and an unstructured region for an optoelectronic component and / or an optoelectronic module.

[0440] For example, the invention also encompasses the use of a substrate, in particular as an optoelectronically active layer, as a contacting layer or as a cover layer for an optoelectronic component, wherein the substrate has an outer surface and an inner surface, wherein the substrate is at least partially transparent, wherein the outer surface and / or inner surface and / or in the volume, in particular within a plane in the volume, of the substrate is formed from a structured and an unstructured region, wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel with a first interference period (pi), wherein the first interference pixel has a periodic grating of at least three cones or inverse cones,and wherein the first interference period of the first periodic dot structure is in the range from 50 nm to 50 pm. The present invention further also encompasses the use of a substrate as a cover layer for an optoelectronic component, in particular with anti-soiling properties (as defined herein), wherein the substrate has an outer surface and an inner surface, wherein the substrate is at least partially transparent, wherein the outer surface of the substrate is formed from a structured and an unstructured region, wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (p1), wherein the first interference pixel (10) has a periodic grating of at least three cones or inverse cones,wherein the interference period of the first periodic dot structure is in the range of 200 nm to 50 pm, and wherein the water contact angle of the outer surface of the cover layer is less than 20° or greater than 150°.,

[0441] Furthermore, the present invention relates to the use of a substrate, in particular as an optoelectronically active layer, as a contacting layer or as a cover layer for an optoelectronic component, in particular with anti-reflection properties (as defined herein), wherein the substrate has an outer surface and an inner surface, wherein the substrate is at least partially transparent, wherein the outer surface and / or inner surface and / or in the volume, in particular within a plane in the volume, of the substrate is formed from a structured and an unstructured region, wherein the structured region has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (p1), wherein the first interference pixel (10) has a periodic grating of at least three cones or inverse cones,and wherein the first interference period of the first periodic dot structure is in the range of 100 nm to 1,000 nm.,

[0442] EXAMPLES OF IMPLEMENTATION

[0443] The present invention is explained in more detail with reference to the following figures and exemplary embodiments, without limiting the invention to these.

[0444] This shows

[0445] Fig. 1 : an optoelectronic component designed as a photovoltaic cell with a cover layer designed as a contacting layer.

[0446] Fig. 2: an optoelectronic component designed as a photovoltaic cell with a cover layer designed as an encapsulation layer.

[0447] Fig. 3: An optoelectronic module comprising several photovoltaic cells with a cover layer designed as an encapsulation layer.

[0448] Fig. 4: A schematic sectional view of a photovoltaic component with a structuring on the outer surface of the cover layer.

[0449] Fig. 5: A schematic sectional view of a photovoltaic component with a structuring on the inner surface of the cover layer

[0450] Fig. 6: A schematic cross-sectional view of an LED with a pattern on the inner surface of the cover layer

[0451] Fig. 7A: a schematic representation of an inverse cone.

[0452] Fig. 7B: a schematic representation of a cone-like depression with a circular base.

[0453] Fig. 7C: a schematic representation of a cone-like depression with an irregular base.

[0454] Fig. 8: a cumulative structure of the dot structure from a superposition of several interference pixels,

[0455] Fig. 9: a dot structure formed from the superposition of several first and second interference pixels,

[0456] Fig. 10: a schematic perspective view of a device according to the invention.

[0457] Fig. 11: a schematic perspective view of a device according to the invention, which contains a deflection element (6) for parallelizing the partial beams.

[0458] Fig. 12: a schematic perspective view of a device according to the invention, which includes a deflection element (7) for widening the angle of the partial beams relative to the optical axis of the beam path (3). Fig. 13A: a schematic perspective view of a device according to the invention, which includes optical elements (6) with a planar, reflective surface that deflect the partial beams onto the focusing element (4).

[0459] Fig. 13B: a schematic perspective view of a device according to the invention, which comprises a galvo mirror (9) as an optical element for beam shaping, which allows a fixed positioning of the substrate to be structured during the structuring process.

[0460] Fig. 14: a schematic perspective view of a device according to the invention, wherein the device contains a polarization element (8) which shifts the phase profile of the partial beams relative to each other, wherein

[0461] A) the beam splitter element (2) is positioned in the beam path (3) close to the laser radiation source (1).

[0462] B) the beam splitter element (2) is positioned in the beam path (3) close to the deflection element (7).

[0463] Fig. 15: a schematic view of the interference pixels with width D resulting on the surface or inside the substrate, and the distribution of the individual interference pixels on the surface or inside the substrate, wherein the interference pixels are shifted relative to each other with the pixel density Pd.

[0464] Fig. 16: a schematic perspective view of the structured substrate (5) with the generated periodic dot structures, consisting of inverse cones, with dimensions in the micro- and submicrometer range, and symbolically the transmission of incident electromagnetic waves with wavelengths greater than the interference period of the generated structures, as well as the diffraction of incident electromagnetic waves with wavelengths in the range or smaller of the generated structures.

[0465] Fig. 17: a schematic perspective view of a device according to the invention, which contains as optical element a galvo mirror (9) with a planar, reflective surface, which deflects the partial beams onto the focusing element (4), and a polygon wheel (91).

[0466] Fig. 18: A graphical representation of the diffraction angle of incident light versus the wavelength of the incident light for structured substrates with three different feature sizes.

[0467] Fig. 19: a schematic perspective view of the structured substrate (5) with the generated periodic dot structures consisting of inverse cones with dimensions in the micrometer range, on which a periodic wave structure in the submicrometer range is superimposed.

[0468] Fig. 20: a schematic

[0469] A) Top view and

[0470] B) a cross-sectional view of a quasi-periodic wave structure in the submicrometer range.

[0471] Fig. 21 : an optoelectronic component with a cover layer whose inner surface has a superposition of a dot structure and a quasi-periodic wave structure and whose outer surface has a dot structure.

[0472] Fig. 22: a visualization of the water contact angle.

[0473] Fig. 1 shows a perspective, schematic view of an optoelectronic component (30) in the form of a photovoltaic cell (30.1). In this exemplary embodiment, a contacting layer 31 is designed as a cover layer 32. The cover layer (32) is designed as a substrate (5) for sealing off the photovoltaic cell (30.1) from the environment and thus forms an upper closure. In this exemplary embodiment, three cover layers (32) are arranged on the photovoltaic cell (30.1), which are separated from one another by contact rails (33), for example made of a metal such as aluminum. The contact rails (33) are electrically connected to a busbar (34), which establishes the electrical connection to an external contact (35).

[0474] Beneath the multiple cover layers (32), functional layers (36) are arranged adjacent to the cover layer (32). These layers comprise an n-doped layer (37), a p-doped layer (38), a boundary layer (39) arranged therebetween, and a further contacting layer (31) for forming an electrical connection to a further external contact (35).

[0475] In this embodiment, the cover layer (32) is designed as an at least partially transparent contacting layer 31, which consists, for example, of a transparent, conductive oxide (TCO).

[0476] A further embodiment of an optoelectronic component (30) designed as a photovoltaic component (30.1) is shown in Fig. 2. The cover layer (32) is designed as an encapsulation layer (40) which, as a substrate (5), protects the photovoltaic component (30.1), also known as a photovoltaic cell, from moisture and other environmental influences. The layers (36) adjacent to the cover layer (32) comprise, in addition to the optoelectronically active layers—here, the n-doped layer (37), the p-doped layer (38), and the boundary layer (39), two contacting layers (31) for establishing the electrical connection to one of the external contacts (35).

[0477] The encapsulation layer (40) here forms the cover layer (32) and ensures an improvement in the optical properties and the efficiency. The cover layer (32) forms a substrate (5) having a periodic dot structure formed from inverse cones (14), in particular a first periodic dot structure. A structured region (28) is formed by the inverse cones (14). The dot structure arranged on the cover layer (32) thus forms the structured region (28). Furthermore, the cover layer has an unstructured region (29) which has precisely no cones and also no further structures. The unstructured region (29) is therefore the entirety of the surface which has no structuring, in particular no dot structures and no line structure. The structured region, in turn, is the entirety of the surface which is structured.The sum of the structured area (28) and the unstructured area (29) therefore forms the entire surface, in particular the outer surface (42) or the inner surface (43).

[0478] An optoelectronic module 41 with a plurality of photovoltaic components 30.1, also referred to as photovoltaic cells, is shown in Fig. 3. The photovoltaic components 30.1 are electrically connected to one another, with at least some of the photovoltaic components 30.1 being connected in series to increase the generated voltage. The cover layer 32 has an outer surface 42 with inverse pins 14 and is designed here as an encapsulation layer 40, which protects all photovoltaic cells 30.1 arranged on the module 41 from environmental influences such as moisture. The inverse pins 14 arranged on the outer surface 42 form the structured region, with the unstructured region 29 being the section of the surface which has no structures, in particular no inverse pins 14 here.The surface of the cover layer 32, in particular the outer surface 42, is thus completely divided into the structured area 28 and the unstructured area 29.

[0479] Preferably, according to a possible embodiment not shown here, one of the contacting layers of the photovoltaic cells is additionally formed as a cover layer with a structured region 28 having a stud or inverse stud. A schematic sectional view of an optoelectronic component is shown in Fig. 4 to visualize the reduction in reflection due to the trap effect. A cover layer 32 designed as a final substrate 5 is shown pointing upwards. Functional layers 36 adjacent to the cover layer 32 are shown below the cover layer 32. The cover layer 32 has an outer surface 42 and an inner surface 43, wherein the outer surface faces away from the functional layers 36 adjacent to the cover layer 32. The inner surface 43 of the cover layer 32 faces the functional layers 36 adjacent to the cover layer 32, i.e., it directly borders them.

[0480] The outer surface 42 of the cover layer 32 has inverse cones 14, with the sectional view lying straight in a row of inverse cones 14. Light 44 incident on the outer surface 42 also partially strikes an interface point 45 arranged within an inverse cone 14. A portion of the light 44 is transmitted at this interface point 45 through the interface into the interior of the cover layer 32. A further portion of the light 44, however, is reflected and strikes another interface point 45 arranged within an inverse cone 14. There, too, a portion of the light 44 is transmitted through the interface between the cover layer 32 and the adjacent layer, and a smaller portion is reflected. In this view, this reflected portion also reaches another interface point 45, where a portion of the light 44 is again transmitted.As a result, the total amount of light 44.1 transmitted through the interface can be significantly increased compared to an outer surface 42 without inverse cones 14.

[0481] Fig. 5 shows a sectional view of an optoelectronic component 30 in which the inner surface 43 of the cover layer has studs 46. These can be produced, for example, using a negative mold (not shown here) having inverse studs.

[0482] Here, too, the light 44 is partially reflected at the interface points 45, and this portion is guided to further interface points 45, where the light 44 is proportionally transmitted through the interface, i.e., penetrates into the layers 36 adjacent to the interface 32 and is not reflected at the interface. Thus, here, too, the total amount of light 44.1 transmitted through the interface can be increased, or the total amount of light 44 reflected at the interface can be reduced. A sectional view of an optoelectronic component 30 configured as an LED 30.2 is shown in Fig. 6. A cover layer 32 with inverse cones 14 arranged on the inner surface 43 is arranged above the functional layers 36 adjacent to the cover layer 32.The light 44 generated within the functional layers 36 adjacent to the cover layer 32 strikes an interface point 45, where it is partially reflected and transmitted. The reflected light 44 also strikes one or more additional interface points 45, so that the total amount of transmitted light 44.1 is also increased here. As a result, a larger portion of the generated light 44 is also coupled out of the LED 30.2.

[0483] Fig. 7A shows a schematic representation of an inverted stud 14 produced by a laser interference method, which has a structure depth x. The base surface 47 of the inverted stud 14 is circular in shape with a diameter d. The side surfaces 48 are smooth.

[0484] A schematic representation of a peg-like depression 49, such as can be generated, for example, by means of an etching process using a mask with circular openings (not shown here), is shown in Fig. 7B. Although the illustrated base surface 47 is circular, the side surfaces 48 are irregularly shaped.

[0485] Fig. 7C shows a schematic representation of a peg-like depression 49 with an irregular base surface 47 and an irregular, completely variable side surface 48. Such a depression is generated, for example, during etching without a mask.

[0486] Fig. 8 visualizes the cumulative structure of the dot structure from a superposition of several interference pixels (10, 11, 12, 13). Each interference pixel (10, 11, 12, 13) consists of several inverse cones (14) introduced into the substrate by laser interference structuring.

[0487] Partial image (A) shows the first interference pixel (10), which has several inverse cones (14, 14.1). Partial image (B) visualizes an overlay of the first interference pixel (10) and the second interference pixel (11), with this overlay consisting of inverse cones (14.1) of the first interference pixel (10) and inverse cones (14.2) of the second interference pixel (11).

[0488] There is an offset (15) between the first interference pixel (10) and the second interference pixel (11), whereby the inverse cones (14.2) of the second interference pixel (11) are shifted by this offset (15) relative to the inverse cones (14.1) of the first interference pixel (10).

[0489] Partial figure (C) visualizes an overlay in which a third interference pixel (12) is additionally superimposed on the first two interference pixels (10, 11). The superimposed structure in partial image (C) thus has inverse cones (14.1) of the first interference pixel (10), inverse cones (14.2) of the second interference pixel (11), and inverse cones (14.3) of the third interference pixel (12). In this exemplary embodiment, the third interference pixel (12) is shifted relative to the second interference pixel (11) in the same spatial direction along the x-axis as the second interference pixel (11) is shifted relative to the first interference pixel (10).

[0490] Partial image (D) shows an overlay in which a fourth interference pixel (13) is also superimposed, which is shifted in a different spatial direction along the y-axis compared to the third interference pixel (12). Thus, the section in partial image (D) has a dot structure consisting of a superposition of four interference pixels (10, 11, 12, 13).

[0491] The graphs arranged below the interference pixels (10, 11, 12, 13) serve to visualize the periodic structures within an interference pixel (10, 11, 12, 13). Due to the formation of the interference pixels (10, 11, 12, 13) via the laser interference structuring process, i.e., according to the interference pattern of the laser (partial beams), each individual interference pixel (10, 11, 12, 13), which was formed during an illumination or irradiation process within a selected pulse duration, exhibits a periodic arrangement of the inverse cones (14). The distance between the inverse cones (14.1) of the first interference pixel (10), which results from the distance between the intensity maxima of the interference image generating the first interference pixel (10), represents the interference period (p1). The intensity corresponds to the intensity in the interference pattern of the laser (partial) beams required to generate the inverse cones (14.1).Thus, the distance between the intensity maxima of the interference image corresponds to the interference period (pi). The second interference pixel (11) has a second interference period (p2).

[0492] Fig. 9 shows a dot structure (16) formed from the superposition of several first interference pixels (10) with a first interference period (p1) and several second interference pixels (11) with a second interference period (p2). The first interference pixels (10) have inverse cones (14.1), which are shown here with a vertical pattern fill. The second interference pixels (11) have inverse cones (14.2), which are shown with a horizontal pattern fill. The interference period (p1) of the first interference pixel (10) is smaller than the second interference period (p2) of the second interference pixel (11).

[0493] In an optional setting of the interference pixels (10, 11) such that the number of inverse cones (14.1, 14.2) within the interference pixels (10, 11) is identical, the area of ​​the interference pixels (10, 11) varies, which is visualized here by the circles. One of the first interference pixels (10) is schematically represented here by all inverse cones (14.1) with vertical pattern filling within the smaller circle. One of the second interference pixels is, in turn, visualized by the inverse cones (14.2), which are represented with a horizontal pattern structuring, within the larger circle.

[0494] The plurality of first interference pixels (10) are arranged adjacent to one another in a repetitive offset from one another, and the plurality of first interference pixels (10) thus form a pattern with the interference period (p1). Furthermore, the plurality of second interference pixels (11) are arranged adjacent to one another in a repetitive offset from one another, and the plurality of second interference pixels (11) thus form a pattern with the second interference period (p2) that differs from the first interference period (p1).

[0495] The graph located below the dot structure (16) visualizes the arrangement of the inverse cones (14.1, 14.2) along a line through the dot structure (16). The intensity maxima correspond to the center of the inverse cones (14.1, 14.2). As in Fig. 8, this graph serves to illustrate the principle. The intensity corresponds to the intensity in the interference pattern of the laser (partial) beams required to generate the inverse cones (14.1, 14.2).

[0496] Fig. 10 visualizes, in a first embodiment, the device according to the invention, comprising a laser radiation source (1) for emitting a laser beam. Arranged in the beam path (3) of the laser beam behind the laser radiation source (1) is a beam splitter element (2), which is movably arranged in the beam path (3). Arranged in the beam path (3) of the laser beam behind the beam splitter element (2) is a focusing element (4). Arranged in the beam path (3) of the laser beam behind the focusing element (4) is a holding device on which a substrate (5), preferably a flat and / or transparent substrate, is mounted.

[0497] In this embodiment, the laser radiation source (1) emits a pulsed laser beam.

[0498] The laser radiation source in this case is a UV laser with a wavelength of 355 nm and a pulse duration of 12 ps. The radiation profile of the laser radiation source in this embodiment corresponds to a top-hat profile.

[0499] In this embodiment, the beam splitter element (2) corresponds to a diffractive beam splitter element. A diffractive beam splitter element here is a beam splitter element that contains micro- or nanostructures. The beam splitter element (2) divides the laser beam into four partial beams.

[0500] In this embodiment, the focusing element (4) corresponds to a refractive, spherical lens that directs the essentially parallel partial beams onto the substrate (5), preferably a flat and / or transparent substrate, such that they interfere there in an interference region. The interference angle in this embodiment corresponds to 27.2°, resulting in an interference period of 550 nm for the periodic dot structure with the same polarization state.

[0501] According to this embodiment, the planar substrate is irradiated once, resulting in a processing time per structural unit, ie per interference pixel, of 12 ps.

[0502] The substrate (5), preferably a flat and / or transparent substrate, is a glass, very specifically a quartz glass, which is mounted on a holding device so that it is movable in the xy plane, perpendicular to the beam path of the laser beam emitted by the laser radiation source (1).

[0503] Fig. 11 visualizes in a further embodiment the device as described in Fig. 10, additionally comprising a deflection element (6) which is located in the beam path (3) of the laser after the beam splitter element (2) and the focusing element (4).

[0504] In this embodiment, the deflection element is a conventional, refractive, convex lens. The partial beams impinge on the deflection element (6) in such a way that, after passing through the deflection element, they run essentially parallel to each other. This allows the point at which the partial beams interfere on the surface or inside the substrate to be adjusted.

[0505] Fig. 12 visualizes a further embodiment of a device based on the structure shown in Fig. 10 and Fig. 11. This structure additionally comprises a further deflection element (7), which is arranged in the beam path (3) of the laser between the beam splitter element (2) and the deflection element (6). In this embodiment, the further deflection element (7) is a conventional, refractive, concave lens. The partial beams impinge on the further deflection element in such a way that their angle to the optical axis of the beam path is widened. This makes it possible to change the interference angle with which the partial beams interfere on the surface or inside the substrate, preferably a flat and / or transparent substrate.

[0506] In this embodiment, all optical elements except for the beam splitter element (2) are fixed along the optical axis of the beam path (3). The interference angle of the partial beams on the substrate is adjusted by moving the beam splitter element (2) along the optical axis of the beam path.

[0507] Fig. 13A shows, in a further embodiment, a device as in Fig. 12, comprising the optical elements (6) with a planar, reflective surface, which are arranged such that they deflect the partial beams onto the focusing element (4).

[0508] In this embodiment, the at least three partial beams are directed onto the substrate by shifting the optical elements (6) at a preferred angle. This eliminates the need for a deflection element in the form of a lens (reference numeral (6) in Fig. 12).

[0509] Fig. 13 B shows a schematic perspective view of a device according to the invention, which comprises a galvo mirror (9) as an optical element for beam shaping, which allows a fixed positioning of the substrate to be structured during the structuring process.

[0510] Fig. 14 visualizes in a further embodiment a device as in Fig. 10, additionally comprising one polarization element (8) per partial beam, which are arranged in the beam path (3) of the laser beam between the deflection element (6) and the focusing element (4).

[0511] The polarization element is arranged in such a way that it changes the polarization of the individual partial beams relative to one another in such a way that a change in the interference pattern results.

[0512] This design is shown in two different configurations. In Fig. 14A, the beam splitter element (2) is positioned in the beam path (3) close to the laser radiation source (1). In Fig. 14B, the beam splitter element (2) is positioned in the beam path (3) close to the deflection element (7). In this way, the interference pattern of the interfering partial beams on the surface of the substrate (5) can be continuously adjusted without having to move the other optical elements in the structure or the substrate itself.

[0513] Additionally, it would also be conceivable for the arrangement to include an additional optical element for beam shaping, which is arranged downstream of the laser radiation source (1) in the beam path (3). In this embodiment, the radiation profile of the laser radiation source corresponds to a Gaussian profile. The optical element for beam shaping converts this profile into a top-hat profile.

[0514] Fig. 15 contains a schematic view of the interference pixels with the width D resulting on the surface or inside the substrate, and the distribution of the individual interference pixels on the surface or inside the substrate, wherein the interference pixels are shifted from each other with the pixel density Pd.

[0515] In this embodiment, the pixel density Pd is smaller than the width of an interference pixel, D. As a result, a planar homogeneous periodic dot structure can be generated on the surface or inside a substrate, preferably a planar and / or transparent substrate, by moving the substrate (5) by means of a pulsed laser beam.

[0516] Preferably, the successively applied interference pixels are arranged next to one another. In this embodiment, there is an overlap between two adjacent interference pixels. Due to the multiple irradiation, self-organization processes within the structured area, i.e., within the inverse cones 14, are preferentially stimulated. This allows a hierarchical structure to be efficiently created.

[0517] Fig. 16 visualizes the structured substrate (5) produced by the inventive method with the generated periodic dot structures consisting of inverse cones with dimensions in the micrometer and submicrometer range. It also symbolically illustrates the transmission of incident electromagnetic waves with wavelengths greater than the interference period of the generated structures, as well as the diffraction of incident electromagnetic waves with wavelengths in the range of or smaller than the generated structures.

[0518] Fig. 17 shows, in a further embodiment, a device as in Fig. 13B, comprising the optical element (91) with a planar, reflective surface, which is a polygon wheel which is arranged such that it rotates around a marked axis. The incident partial beams are deflected such that they strike a galvo mirror (9), which reflects the beams via a

[0519] The focusing element (4) directs the beams onto the substrate. The rotation of the polygon wheel causes the point at which the beams are focused on the substrate to move along a line during the exposure process. The partial beams thus scan the substrate, which leads to increased process speed.

[0520] Fig. 18 graphically illustrates the transmission and diffraction capabilities of a structured substrate as a function of the structure size. The diffraction angle of light is shown as a function of its wavelength for structures with three different structure sizes. If the wavelength of the incident light is longer than the structure size, the light is completely transmitted. At wavelengths in the range of the structure size or smaller, diffraction occurs. The diffraction angles can be seen in the graph.

[0521] Fig. 19 visualizes the structured substrate (5) produced by the inventive method with the generated periodic dot structures consisting of inverse cones with dimensions in the micrometer range. Superimposed on this periodic dot structure in the micrometer range is a periodic wave structure in the submicrometer range, which can also be produced in a single production step by the inventive method described herein.

[0522] Fig. 20A visualizes a quasi-periodic wave structure 19 in a plan view and Fig. 20B in a sectional view, as it has a structured substrate which can be produced by a method disclosed herein, in particular by multiple irradiation or by single irradiation with high intensity. The sectional view of Fig. 11B represents a cross-section through the structure shown in Fig. 11A approximately along the section line AA. Self-organization processes occurring in the materials lead to the formation of wave-like structures with wave crests 20 and wave troughs 21 within such an irradiated area. The resulting structures generally exhibit a certain periodicity, although defects 22, i.e., irregularities, also occur.Thus, in contrast to a truly periodic structure, such a structure exhibits both deviations in the structural dimensions, particularly in the distances between the wave crests and the wave troughs, as well as defects, so that the generated wave structure is not homogeneous.

[0523] Fig. 21 shows an optoelectronic component 30 with a cover layer 32. The cover layer 32 has an outer surface 42, which the optoelectronic

[0524] Component 30 closes off from the environment, and has an inner surface 43. The functional layers 36 adjacent to the cover layer 32 border the inner surface 43. According to this embodiment, the inner surface 43 has studs 46 that form a dot structure, with a superimposed structure, which here is designed as a quasi-periodic wave structure 19, being arranged on the studs 46. A periodic dot structure composed of inverse studs 14 is arranged on the outer surface 42, with the interference period of the dot structures on the outer surface 42 being significantly smaller than that of the dot structure on the inner surface 43.

[0525] A visualization of the water contact angle 23 is shown in Fig. 22. Here, water 24 is arranged in droplet form on a substrate 5. Outside the water droplet 24, air is present in the gas phase 25. The water contact angle 23 is the angle between the surface of the substrate 5 and the tangent 26 adjacent to the water droplet 24. The tangent 26 is viewed as adjacent to the surface of the substrate 5. To determine the water contact angle 23, a shadow image of a water droplet 24 is typically taken.

[0526] LIST OF REFERENCE SYMBOLS

[0527] 1 laser radiation source

[0528] 2 beam splitter element

[0529] 3 Beam path

[0530] 4 Focusing element

[0531] 5 Substrat

[0532] 6 additional deflection element

[0533] 7 Deflection element

[0534] 8 Polarization element

[0535] 9 Focusing mirror or galvo mirror

[0536] 91 Polygon wheel

[0537] 10 first interference pixel

[0538] 11 second interference pixel

[0539] 12 third interference pixel

[0540] 13 fourth interference pixel

[0541] 14 inverse cones

[0542] 14.1 Inverse cones of the first interference pixel

[0543] 14.2 Inverse cones of the second interference pixel

[0544] 14.3 Inverse cones of the third interference pixel

[0545] 14.4 inverse cones of the fourth interference pixel

[0546] 15 Offset

[0547] 16 point structure

[0548] Pi first interference period p2 second interference period

[0549] 19 quasi-periodic wave structure

[0550] 20 Wave Mountain

[0551] 21 wave trough

[0552] 22 Defect

[0553] 23 Water contact angle

[0554] 24 drops of water

[0555] 25 Gas phase

[0556] 26 Tangent

[0557] AA cutting line

[0558] 28 structured area

[0559] 29 unstructured area

[0560] 30 optoelectronic component 30.1 photovoltaic cell, photovoltaic component

[0561] 30.2 LED (light-emitting diode)

[0562] 31 Contacting layer

[0563] 32 Top layer

[0564] 33 metal rail

[0565] 34 Busbar

[0566] 35 External contact

[0567] 36 functional layers adjacent to the top layer

[0568] 37 n-doped layer

[0569] 38 p-doped layer

[0570] 39 Boundary layer

[0571] 40 encapsulation layer

[0572] 41 Optoelectronic module

[0573] 42 Outer surface

[0574] 43 Inner surface

[0575] 44 Light

[0576] 44.1 Transmitted light

[0577] 45 interface point

[0578] 46 cones

[0579] 47 floor space

[0580] 48 side surface

[0581] 49 Deepening

[0582] D Width of the interference pixel

[0583] Pd pixel density? d diameter x structure depth

Claims

PATENT CLAIMS 1 . Optoelectronic component (30), comprising • a cover layer (32) having an outer surface (42) and an inner surface (43), wherein the cover layer (32) is at least partially transparent, • at least one functional layer which is arranged at least partially on the inner surface (43) of the cover layer (32), characterized in that the outer surface (42) and / or inner surface (43) is formed from a structured (28) and an unstructured region (29), wherein the structured region (28) has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi), wherein the first interference pixel (10) has a periodic lattice of at least three cones (46) or inverse cones (14), wherein the interference period (pi) of the first periodic dot structure is in the range from 50 nm to 50 pm.

2. Optoelectronic component (30) according to claim 1, wherein the structured region (28) is formed from the first periodic dot structure, wherein the first periodic dot structure consists of one or more interference pixels arranged offset from one another.

3. Optoelectronic component (30) according to claim 1, wherein the structured Region (28) further comprises a second periodic dot structure, wherein the second periodic dot structure is formed from at least one second interference pixel (11) with a second interference period (p2), wherein the second interference pixel (11) comprises a periodic grating of at least three cones (46) or inverse cones (14) with a second interference period (p2).

4. Optoelectronic component (30) according to claim 1 or 3, wherein the structured region (28) has a periodic line structure with an interference period in the micro or submicrometer range.

5. Optoelectronic component (30) according to one of claims 1 to 4, wherein the water contact angle (23) of the outer surface (42) of the cover layer (32) is less than 20° or greater than 130°.

6. Optoelectronic component (30) according to one of claims 1 to 5, wherein the cones (46) or inverse cones (14) of the first interference pixel (10) have a mean structural depth in the statistical average dso in the range from 10 nm to 500 nm, preferably of a maximum of 1 pm.

7. Optoelectronic component (30) according to one of claims 1 to 6, wherein the first dot structure has an aspect ratio of at least 0.5 or at most 0.

1.

8. Optoelectronic component (30) according to one of claims 1 to 7, wherein the pins (46) or inverse pins (14) of the structured region (28) have side surfaces (48), wherein the side surfaces (48) have a superimposed quasi-periodic line structure or a smooth surface.

9. Optoelectronic component (30) according to one of claims 1 to 8, wherein the base surface (47) of the pin (46) or of the inverse pin (14) is circular or elliptical.

10. Optoelectronic component (30) according to one of claims 1 to 9, wherein the cover layer (32) has a transmittance of at least 50% for each wavelength in a sub-range of the electromagnetic spectrum, preferably in the range of visible light or near-infrared light.

11. Optoelectronic component (30) according to one of claims 1 to 10, wherein the cover layer (32) is designed as an optical element.

12. Optoelectronic component (30) according to one of claims 1 to 11, wherein the cover layer (32) is flexible, preferably formed as a film.

13. Optoelectronic component (30) according to one of claims 1 to 12, wherein the cover layer (32) comprises a glass and / or a polycarbonate.

14. Optoelectronic component (30) according to one of claims 1 to 13, wherein the cover layer (32) comprises a first cover layer and a second cover layer.

15. Optoelectronic component (30) according to one of claims 1 to 14, wherein the optoelectronically active layer comprises an organic semiconductor material and / or an inorganic semiconductor material, preferably silicon, CdTe, GaAs, CIS or CIGS.

16. Optoelectronic component (30) according to one of claims 1 to 15, wherein the optoelectronic component (30) is a photovoltaic component (30.1).

17. Optoelectronic component (30) according to one of claims 1 to 16, wherein the optoelectronic component (30) is a light-emitting diode (30.2).

18. Optoelectronic component (30) according to one of claims 1 to 17, comprising a coating which is arranged on the cover layer, wherein the coating has hydrophobic or hydrophilic properties.

19. Optoelectronic module (41) comprising at least two optoelectronic components (30) according to one of the preceding claims.

20. Optoelectronic module (41) according to claim 19, wherein the cover layer (32) is formed as a single-layer or multi-layer cover layer (32) which extends over the optoelectronic module (41).

21. Optoelectronic module (41) according to claim 19 or 20, wherein the cover layer (32) is formed as a single-layer or multi-layer cover layer (32) which extends over the optoelectronic module (41).

22. A method for producing an optoelectronic component (30), in particular according to one of claims 1 to 18, comprising the following steps: (a) providing a first final layer having an inner surface (43), (b) applying a functional layer, preferably an optoelectronically active layer or a contacting layer, to at least a partial area of ​​the inner surface (43) of the first final layer, (c) applying a second final layer to at least a partial region of the functional layer, wherein the first or the second final layer is formed as a cover layer (32) of the optoelectronic component (30), wherein the cover layer (30) has an outer surface (42) and an inner surface (43), wherein the outer surface (42) and / or the inner surface (43) of the cover layer (32) is formed from a structured (28) and an unstructured region (29), or wherein the outer surface (42) and / or the inner surface (43) of the cover layer (32) is structured following step (c) such that it is formed from a structured (28) and an unstructured region (29), characterized in that the structured region (28) has a first periodic dot structure,wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi), wherein the first interference pixel (10) has a periodic grating of at least three cones (46) or inverse cones (14), wherein the first interference period (pi) of the first periodic dot structure is in the range from 50 nm to 50 pm., Method according to claim 22, wherein the periodic dot structure is generated by a laser structure application method. Method according to claim 22 or 23, direct laser interference structuring is generated, wherein the first periodic dot structure is generated by superimposing at least three laser beams. Method according to one of claims 22 to 24, wherein the periodic dot structure is first generated on a negative mold by means of a laser interference method and is applied to the cover layer (32) by means of the negative mold. Method according to one of claims 22 to 25, wherein, in the laser interference method, partial beams are generated by means of a beam splitter element (2), and the interference period (p) of an interference pixel, preferably the first interference period (pi) of the first interference pixel (10), is continuously adjusted by means of a displacement of the beam splitter element (2), wherein the further optical elements are preferably fixed.Method according to one of claims 22 to 26, wherein the periodic dot structure within an interference pixel is generated by applying a single laser pulse by means of single irradiation. Method according to one of claims 22 to 27, wherein a hierarchical structure with a line structure arranged in the pegs (46) or inverse pegs (14) is generated by means of multiple irradiation of an interference pixel with identical process parameters. Method according to one of claims 22 to 28 or claim 24, wherein a periodic line and / or dot structure superimposed on the first periodic structure is generated by means of multiple irradiation with varied process parameters. Use of a substrate (5) as a cover layer for an optoelectronic component, wherein the substrate (5) has an outer surface (42) and an inner surface. Surface (43), wherein the substrate (5) is at least partially transparent, wherein the outer surface (42) and / or inner surface (43) of the substrate (5) is formed from a structured (28) and an unstructured region (29), wherein the structured region (28) has a first periodic dot structure, wherein the first dot structure is formed from at least one first interference pixel (10) with a first interference period (pi), wherein the first interference pixel (10) has a periodic grating of at least three cones (46) or inverse cones (14), and wherein the first interference period (pi) of the first periodic dot structure is in the range from 50 nm to 50 pm.

Images