Glazing unit, procedure for its production and use

Abstract

Glazing unit (1) for aesthetic design, containing or comprising at least one polymer (3), the polymer (3) having a first structured surface (4), on which a photonic structure (2) has been applied, which is configured to reflect a first partial spectrum of incident electromagnetic radiation and to transmit a second partial spectrum of incident electromagnetic radiation, characterized in that the reflected proportion corresponds to a higher harmonic and is in the visible spectral region.

Description

Glazing unit, procedure for its production and use The invention relates to a glazing unit, comprising at least one polymer, as well as a process for its production and use. Glazing units of the type mentioned above can be used, for example, as a facade element. The market for building-integrated photovoltaics (BIPV) and building-integrated solar thermal energy (BIS) presents significant potential both nationally and globally. The currently limited design possibilities hinder the widespread adoption and application of these technologies in buildings. To increase acceptance and appeal, there is a growing demand for solar modules with photovoltaic cells and solar thermal collectors whose function can be concealed with color effects, rendering them virtually invisible. Particularly desirable is the ability to customize the color (e.g., incorporating a company logo) while simultaneously achieving maximum efficiency.In this regard, the color printing of the modules should be as independent as possible of the viewing angle, and glare effects should be avoided depending on the location of use. The aforementioned concepts either result in an intolerable loss of efficiency, are limited in their color choices, or are not industrially feasible. For example, if the goal is to design BIPV modules in a more visually appealing way, there are essentially two different options. One approach is to design the module so that the cells are not visible by inserting a glass panel—for example, colored or frosted glass—in front of them. In this case, the solar modules are no longer visible. In this respect, it is important to minimize the reduction in efficiency that was previously unavoidable due to the glass panel, so that a sufficient impact on the building's energy balance can be achieved. Alternatively, one can try to leave the cells visible and consciously use them as a design element by choosing a special shape, size, or position for the solar cells. In the first option, the colored module's cover glass can be used as a colored glass panel. One possibility is to color or print the glass with absorbent color pigments. This allows for a relatively free and simple choice of colors, but because the colored pigments absorb a partial range of the electromagnetic spectrum, significant losses occur when the goal is truly invisible photovoltaics. Therefore, widespread adoption has been practically ruled out. Luminescent materials can also be used, although in this case, the overall efficiency remains good. However, even with luminescent materials, industrial implementation is still a long way off, and the choice of color depends on the available luminescent materials and is therefore limited. By using a selectively reflective coating, overall efficiency is only minimally affected, and more design flexibility is available. The dependence of the color on the viewing angle is a disadvantage, which is generally undesirable for buildings. A glazing unit with a coating that reduces the angle-dependent problem is known from patent US 2015 / 0249424 A1. This coating consists of a complex layered structure and results in a reflection loss of 8% to 12%. A corresponding product (Kromatix™) is available in six different colors. However, this technology has considerable drawbacks. Angle-independent color printing relies on a very special and complex thin-film filter, which limits the number of possible colors and degrees of freedom, as well as the achievable color saturation. A glazing unit according to the preamble of claim 1 is known from document WO2015155357. Therefore, based on this state of the art, the invention is based on the objective of providing a glazing unit with improved properties. According to the invention, the objective is achieved through a glazing unit according to invention 1, a method for producing this glazing unit according to claim 10, a solar module having the glazing unit according to claim 14, and a solar thermal collector according to claim 15. Advantageous improvements of the invention are found in the dependent claims. According to the invention, a glazing unit is proposed for the aesthetic design, for example, of facade surfaces and roof surfaces, comprising or consisting of at least one photonic structure and a polymer, the polymer having a first structured surface on which the photonic structure has been applied. The glazing unit according to the invention contains at least one transparent or translucent substrate material, hereinafter referred to as "glass". Regardless of the designation as "glass", the transparent or translucent material is composed of at least one polymer onto which the described structured surface and photonic structure are then applied. In the context of this description, photonic structures are modulations of the refractive index that occur or are created in transparent or translucent solids. Therefore, a photonic structure contains at least first spatial regions with a first refractive index and second spatial regions with a second refractive index, such that the propagation of light is influenced by diffraction, reflection at interfaces, and / or interference. To achieve this, the refractive index is modulated in at least one spatial direction in dimensions that are on the same order of magnitude as the wavelength of the relevant light. In some embodiments of the invention, the first and second spatial areas may be made up of a plurality of thin layers of different compositions or two different compositions and optionally different thicknesses. In some embodiments, the optical thickness of the individual layers may correspond to approximately one-quarter of the design wavelength, at which the principal reflection maximum (zero harmonic) occurs. The photonic structures used according to the invention are configured to reflect a first partial spectrum of incident electromagnetic radiation and to transmit a second partial spectrum of incident electromagnetic radiation, the reflected portion corresponding to a higher harmonic and located in the visible spectral region. In this respect, a higher harmonic has a shorter wavelength or a lower average wavelength within a wavelength distribution than the principal reflection maximum (zero harmonic). In some embodiments of the invention, the second or third harmonics may be used. In non-dispersive media, the higher harmonics occur at integer multiples of the frequency of the principal reflection maximum (zero harmonic). According to the invention, it has been recognized that using a higher harmonic of a thin-film filter in the visible spectral region offers greater color saturation and a wider range of possible colors and design possibilities. By combining the photonic structure with the structured surface according to the invention, the angle dependence of the color impression can be reduced or eliminated. A building equipped with the glazing unit according to the invention presents the same color impression from many or all viewing angles. The first and second spatial areas of the photonic structure can be arranged non-periodically. The first and second spatial areas can be arranged periodically. For this purpose, layers of the same thickness and composition can be used. The photonic structure can reflect light of a predetermined wavelength or wavelength range and transmit other wavelengths, for example, through interference effects. The reflected wavelength or the maximum value of the wavelength range is also referred to hereafter as the Bragg wavelength. The width of the reflected wavelength range at perpendicular incidence can be less than 75 nm, less than 65 nm, or less than 60 nm. According to the invention, such a photonic structure is located on a structured glass surface.For this purpose, the glass has at least one first structured surface, onto which the photonic structure has been applied. This is therefore also referred to as the three-dimensional photonic structure. The first structured surface may comprise a partial surface of one side of the glass, or an entire side of the glass may be provided with the structured surface. A structured surface, within the meaning of the present invention, denotes a structure having elevations and depressions. In some embodiments of the invention, the RMS roughness can be found between approximately 30 nm and approximately 100 µm, or between approximately 80 nm and approximately 10 µm. The structured surface may be structured periodically or aperiodically. According to the invention, in some embodiments, a thin-film filter is applied as a photonic structure onto a structured surface. This thin-film filter is thus also structured, so it cannot be considered a flat thin-film filter, as is usually the case. However, the thin-film filter can be designed as a Bragg filter or a similar filter. Nevertheless, according to the invention, it has been recognized that some properties of the structure designed as a thin-film filter change significantly upon application to a structured glass, such that it can no longer be considered a one-dimensional thin-film filter.In this implementation, the principal reflection maxima are preserved, as are the higher harmonics of the thin-film structure. Their exact position can be influenced by the layer sequence of the individual thin-film filter layers. One of the essential influences of the structured surface is its effect on the angle dependence of the reflection peaks. Therefore, for the purposes of this description, a flat thin-film filter on a structured surface is also called a three-dimensional photonic structure. In some embodiments, the average refractive index of the glazing unit may be greater than approximately 1.6, or greater than approximately 1.8, or greater than approximately 1.95, in each case determined at a wavelength of 550 nm. The average refractive index is defined as the average of the refractive indices weighted by the volume proportions of the respective material. This can be determined through the following procedural steps: determination of the total thickness of all Dges layers of the thin-film filter of the photonic structure, for example, through optical microscopy or scanning electron microscopy, determination of the number of different layers of the thin-film filter, for example, with EDX, thereby determining the number of symmetry elements Nsym of the thin-film filter, determination of the wavelength of the main peak LDh p , Determination of the wavelength of the m harmonic. LDm, determination of ma through the division of peak wavelengths: m = LDh p / LDm-1 and rounding to an integer, Calculation of the average refractive index n according to the following formula: n = Nsym / Dges x 0.5 x LDm x (m+1). According to the invention, at least one first side of the glass is provided with the photonic structure according to the invention, which is arranged on a structured surface. In some embodiments, this first side may be the inner side facing away from the elements, so that the photonic structure is protected from exposure to the elements and dirt. In other embodiments of the invention, the first side of the glass with the photonic structure according to the invention may be the outer surface during operation or after final assembly. Therefore, the color saturation can be increased. The photonic structure exhibits a higher harmonic in the visible spectral region. This can be achieved by increasing the layer thicknesses of the photonic structure.This characteristic has the effect of narrowing the spectral width of the reflected wavelength range. A higher harmonic is characterized by the fact that the reflected wavelength, or the average value of a wavelength range, is smaller than the reflected wavelength, or the average value of a wavelength range, of the zero harmonic or the principal wavelength. In some embodiments of the invention, the highest harmonic is the second or third harmonic. Therefore, color saturation can be increased in both reflection and transmission. Consequently, a larger proportion of the light spectrum is available for use by photovoltaics or thermal collectors, and at the same time, an observer perceives a homogeneously colored surface rather than individual cells. In some embodiments of the invention, the reflection losses of the glazing unit can amount to less than 12% or less than 9%. By applying the three-dimensional photonic structure according to the invention to a modular glass of a photovoltaic module, the glazing unit according to the invention can be used as part of a photovoltaic module. In this respect, the production process of the photovoltaic module can remain virtually unchanged. However, the color design can be freely selected, so that the photovoltaic modules according to the invention can have a wider range of applications. The photovoltaic modules can be used on surfaces where the use of conventional photovoltaic modules has been prohibited until now for creative reasons. Similarly, solar thermal collectors can also be equipped with the glazing unit according to the invention.Furthermore, glazing units with the selective coating can be used directly without lamination, for example, in non-laminated photovoltaic modules. In some embodiments of the invention, the photonic structure may have first layers, which contain a first material having a first refractive index, and second layers, which contain a second material having a second refractive index, the first refractive index ranging from approximately 1.5 to approximately 2.2 and the second refractive index ranging from approximately 1.8 to approximately 2.5. In some embodiments of the invention, the refractive index contrast may range from approximately 0.2 to approximately 0.9. Therefore, color saturation is increased and reflection losses can be further reduced. In some embodiments of the invention, the three-dimensional photonic structure comprises or consists of a thin-film filter, which may be a periodic thin-film filter, in particular a Bragg filter. In this regard, the Bragg filter may comprise or consist of alternating layers of a first material and a second material. The first and / or second material may contain and consist of ZrO2 and / or Nb2O5 and / or TiO2 and / or Si3N4 and / or SiO2 and / or AlN, SnO2 and / or AhO3 and / or HfO2 and / or Ta2O5 and / or SiOxny and / or AlOxny and / or ZnO and / or Bi2O3 and / or In2O3 and / or WO3 and / or MoO3. In some embodiments of the invention, the first and / or second material may additionally contain a dopant. Examples of Bragg filter implementations are the following layered structures a) through c): a) Si3N4 in particular at a thickness of 140 nm, TiO2 in particular at a thickness of 170 nm, Si3N4 in particular at a thickness of 200 nm, TiO2 in particular at a thickness of 170 nm and Si3N4 in particular at a thickness of 140 nm, or b) Si3N4 in particular at a thickness of 165 nm, TiO2 in particular at a thickness of 190 nm, Si3N4 in particular at a thickness of 240 nm, TiO2 in particular at a thickness of 190 nm and Si3N4 in particular at a thickness of 165 nm, or c) Si3N4 in particular at a thickness of 120 nm, TiO2 in particular at a thickness of 140 nm, Si3N4 in particular at a thickness of 170 nm, TiO2 in particular at a thickness of 140 nm and Si3N4 in particular at a thickness of 120 nm. To prevent oxidation of the Si3N4 layers if it forms an outer layer of the photonic structure, a passivation layer can be placed on top of it. The passivation layer can contain or be composed of SiO2 and, for example, have a thickness of approximately 120 nm to approximately 210 nm. The following table shows examples of photonic structures and the resulting color impression of the glazing units: In some embodiments, the optional top layer, which contains or is composed of SiO2, is also omitted. For protection against environmental influences, glazing units of this type can be laminated without a final SiO2 layer onto at least one polymer film. Whenever such a lamination is omitted, the final SiO2 layer, with a thickness of between approximately 100 nm and approximately 230 nm, can decrease total reflection and / or reduce degradation due to environmental influences. Whenever lamination of the glazing unit is planned, a final SiO2 layer can improve the bond to the laminated film. For this purpose, the final SiO2 layer can also be selected to be thinner and, for example, have a thickness between approximately 5 nm and approximately 50 nm or between approximately 3 nm and approximately 100 nm. In this regard, the term "structured glass" means glass having a first structured surface onto which the thin-film filter has been applied as a three-dimensional photonic structure. In some embodiments, the glazing unit has several three-dimensional photonic structures, each of which reflects different wavelength ranges. In some embodiments of the invention, two or three three-dimensional structures can be used, resulting in different colors, for example, red, green, and blue. Therefore, it is possible to cover a wide color space through additive color mixing. A wide color space of this type can also be achieved by using a single three-dimensional photonic structure with several reflection peaks at different wavelengths or wavelength ranges. In some embodiments of the invention, this can be achieved through non-periodic structures or through periodic structures with varying layer thicknesses. In some embodiments, the glass in the glazing unit may have a second structured surface opposite the first. The second structured surface can serve, for example, as an anti-reflective coating. In this embodiment, even greater color saturation can be achieved due to the lack of reflection on the front side. In some embodiments, the glazing unit may have first partial surfaces, which have a first photonic structure, and second partial surfaces, which have a second photonic structure or no photonic structure at all. If the partial surfaces of the glazing unit have no photonic structure, they appear black. If the partial surfaces of the glazing unit have a different photonic structure than other partial surfaces, then these may appear in a different color if the thickness of the layers or the material of the individual layers differ. In other embodiments of the invention, partial surfaces may be provided with the same Bragg filter but have lower roughness or a different surface structure. Therefore, a dependence on the angle of the color impression can be adjusted.Due to the division into first and second partial surfaces, patterns, logos or other design elements can be made on the glazing unit. According to the invention, a method for producing a glazing unit is further provided. In this regard, the first structured surface is produced on the glass, and then the three-dimensional photonic structure is applied to this first structured surface. In some embodiments, the application of the three-dimensional photonic structure can be carried out on the first structured surface of the glass via sputtering. This is a common process for coating architectural glass, so the glazing unit according to the invention can be easily produced using existing facilities. Therefore, in this process, standard cover glass for solar modules and solar thermal collectors can be used, which can then be used in the usual way for the further production of solar modules or solar thermal collectors. In some embodiments, the first textured surface of the glass can be produced by sandblasting, etching, stamping, casting, or laminating. As previously mentioned, in some embodiments, the glazing unit may have a second textured surface. This can also be produced by sandblasting, etching, stamping, casting, or laminating. If a division into partial first and second surfaces with different roughness is desired, optional masking can be applied. In particular, the mask can be applied using a printing process. If the glazing unit has first partial surfaces, which have a first photonic structure, and second partial surfaces, which have a second photonic structure or no photonic structure, a mask can also be applied before generating the photonic structure. In some embodiments of the invention, this can be done by printing. If the mask is made of organic material, it can be disposed of by incineration. In some embodiments of the invention, the incineration can be carried out simultaneously with a heat treatment to cure the glazing unit. Apart from that, according to the invention, a solar module is provided, which features a glazing unit according to the invention, particularly as described above. In this respect, the glazing unit according to the invention may be present in known solar modules. In particular, the solar module may comprise the glazing unit, a first inset film, a solar cell, a second inset film, and a back-side foil. Examples of inset film materials are ethylene-vinyl acetate and / or silicone. In some embodiments, the glazing unit may be applied over a solar thermal collector known by itself. The glazing unit according to the invention can be used for the aesthetic design of a plurality of different areas and surfaces. In this respect, it is possible for part of the area / surface to be glazed with the glazing unit according to the invention, while other parts of the area / surface are designed in a conventional manner. The glazing unit according to the invention can be used as cover glass for building-integrated photovoltaics (BIPV), building-integrated solar thermal systems, rooftop installations with a special color design, as standard non-solar glazing, for example, in the parapet area of ​​fully glazed buildings, or as colored glazing for vehicles. In the latter case, an inscription, pattern, or logo can be incorporated, and light can still pass through the glazing to the space behind it. The invention will now be explained in more detail by means of figures and examples of embodiment without limiting the general inventive idea. In this regard, it shows: Figure 1 shows a glazing unit according to the invention in a first embodiment. Figure 2 shows a second embodiment of the glazing unit according to the invention. Figure 3 shows a third embodiment of the glazing unit according to the invention. Figure 4 shows a fourth embodiment of the glazing unit according to the invention. Figures 5a and 5b show a fifth embodiment of the glazing unit according to the invention. Figure 6 shows a sixth embodiment of the glazing unit according to the invention. Figure 1 shows a first embodiment of the glazing unit 1 according to the invention. In this respect, Figure 1 depicts a three-dimensional photonic structure 2 and a glass 3, the glass 3 having a first structured surface 4, onto which the three-dimensional photonic structure 2 has been applied. Glass 3 represents a support material for the three-dimensional photonic structure. Glass 3 is a transparent or translucent material, which may also be composed of several layers (not shown) made of different materials. For example, Glass 3 may have an anti-reflective coating or, as laminated safety glass, may contain at least one polymer layer, which is bonded across its entire surface to adjacent glass layers. Regardless of whether it is designated as "glass," the substrate consists entirely of at least one polymer onto which the described structured surface and photonic structure are then applied. In this first embodiment, the three-dimensional photonic structure 2 is constructed as a thin-film filter from several alternating individual layers, each containing either Si3N4 or TiO2. By choosing the distances between layers, the reflection wavelength, and thus the color pattern of the glazing unit 1, can be selected to display a specific color, for example, red. The distances between layers can be selected from approximately 100 nm to approximately 250 nm. The number of individual layers can range from 1 to approximately 100 or from approximately 3 to approximately 20. The individual layers of the photonic structure 2 have been applied onto a structured surface 4, which can be produced in a manner known to itself through sandblasting, rolling, stamping, casting, or pickling. Since the glass 3 has a structured surface 4, the thin-film filter is also structured accordingly, so it cannot be considered a flat thin-film filter, as is usually the case. However, the thin-film filter can be designed as a Bragg filter or a similar filter. Nevertheless, according to the invention, it has been recognized that some properties of the structure designed as a thin-film filter change significantly when applied to a structured glass 3, so that it can no longer be considered a one-dimensional thin-film filter. In this implementation, the principal reflection maxima are preserved, as are the higher harmonics of the thin-film structure, and their exact position can be influenced by the layering sequence of the individual layers of the thin-film filter.One of the essential influences of the structured surface is its effect on the angle dependence of the reflection peaks. The color design of glazing unit 1 exhibits less variation when the viewing angle changes than known colored glazing units. At the same time, the transmission of the spectrum usable for solar energy generation is greater than that of known colored glazing units, particularly pigmented ones. Figure 2 shows a second embodiment of the glazing unit 1 according to the invention, in which three different three-dimensional photonic structures 2a, 2b, and 2c have been generated on the structured surface 4 of the glass 3. These structures differ in that they exhibit different colors, that is, they reflect light at different wavelengths in each case. In this way, it is also possible to generate mixed colors by superimposing three primary colors, thereby further increasing the design possibilities. The different three-dimensional photonic structures 2a, 2b, and 2c can be applied to the previously structured surface 4 of the glass 3 through successive sputtering. The photonic structures 2a, 2b, and 2c may differ in terms of composition, thickness, and / or number of individual layers. The third embodiment of the glazing unit 1 according to the invention as shown in Figure 3 shows that the glass 3 has a second structured surface 5, which is opposite the first structured surface 4 of the glass 3. The second structured surface 5 can serve to prevent unwanted reflections on the surface, which could dazzle passersby and can further reduce the intensity passing through the glazing unit. The fourth embodiment of the glazing unit 1 according to the invention also features a second structured surface 5, a glass 3, and a first structured surface 4. In this respect, it corresponds to the third embodiment of the glazing unit according to the invention shown in Figure 3. However, similarly to Figure 2, the glazing unit 1 according to Figure 4 features three different three-dimensional photonic structures 2a, 2b, and 2c, which produce a different color impression, so that together they create the overall impression of a mixed color. The fifth embodiment of the glazing unit according to the invention shown in Figures 5a and 5b features a three-dimensional photonic structure 2, a structured surface 4, and a glass 3. A design element 6 is located on the surface of the glass 3. In the simplest case, this can be generated with an adhesive sheet. This is represented in cross-section in Figure 5a, and as a top view in Figure 5b, in which the design element is illustrated in the form of a letter for illustrative purposes. However, it is advantageous for the glazing unit used to generate a design element to have first partial surfaces, which exhibit a first photonic structure, and second partial surfaces, which exhibit either a second photonic structure or no photonic structure at all. If the partial surfaces of the glazing unit do not exhibit any photonic structure, they appear black. If selected partial surfaces of the glazing unit exhibit a photonic structure different from other partial surfaces, then they may appear in a different color if the thickness of the layers, the material of the individual layers, and / or the number of individual layers differ. In other embodiments of the invention, partial surfaces may be provided with the same Bragg filter but exhibit lower roughness or a different surface structure.Therefore, greater dependence on the angle of the color print can be adjusted. Due to the division into first and second partial surfaces, patterns, logos, or other design elements can be applied to the glazing unit. At the same time, high transmission remains a key advantage of the invention across the entire surface. Figure 6 shows a sixth embodiment of the invention. It shows how a glazing unit 1 has been installed in a solar module according to the invention. In this respect, the solar module has the glazing unit 1 as its cover glass. The glazing unit according to the invention, comprising glass 3 and photonic structure 2, rests on a first inset film 7a, which is made, for example, of ethylene-vinyl acetate or silicone. The solar module also contains a second inset film 7b. The inset films 7a and 7b enclose at least one photovoltaic cell 8. This cell may be a known photovoltaic cell. The invention does not disclose the use of any particular cell as a solution principle. Finally, the solar module features a standard back-side foil 9. Solar modules of this type can be used for building-integrated photovoltaics. Clearly, the invention is not limited to the embodiments shown. Therefore, the foregoing description should be considered explanatory rather than limiting.The following claims should be understood to include a named feature. This does not exclude the presence of additional features. Whenever the above description defines "first" and "second" embodiments, this designation serves to distinguish between two similar embodiments without establishing an order of precedence.

Claims

1. A glazing unit (1) for aesthetic design, comprising or consisting of at least one polymer (3), the polymer (3) having a first structured surface (4) on which a photonic structure (2) has been applied, the latter being configured to reflect a first partial spectrum of incident electromagnetic radiation and to transmit a second partial spectrum of incident electromagnetic radiation, characterized in that the reflected proportion corresponds to a higher harmonic and is in the visible spectral region.

2. A glazing unit (1) according to claim 1, wherein the average refractive index of the photonic structure (2) is greater than approximately 1.6, greater than approximately 1.8, or greater than approximately 1.

95.

3. A glazing unit (1) according to any one of claims 1 or 2, comprising the photonic structure (2) or consisting of a Bragg filter. 4.Glazing unit (1) according to any one of claims 1 to 3, the photonic structure (2) having first layers, which contain a first material having a first refractive index, and the photonic structure (2) having second layers, which contain a second material having a second refractive index, the first refractive index being between approximately 1.5 and approximately 2.2 and the second refractive index being between approximately 1.8 and approximately 2.5.Glazing unit (1) according to any one of claims 1 to 4, the photonic structure (2) having one of the following layer structures: - Si3N4 in a thickness of 140 nm, TiO2 in a thickness of 170 nm, Si3N4 in a thickness of 200 nm, TiO2 in a thickness of 170 nm and Si3N4 in a thickness of 140 nm, or - Si3N4 in a thickness of 165 nm, TiO2 in a thickness of 190 nm, Si3N4 in a thickness of 240 nm, TiO2 in a thickness of 190 nm and Si3N4 in a thickness of 165 nm, or - Si3N4 in a thickness of 120 nm, TiO2 in a thickness of 140 nm, Si3N4 in a thickness of 170 nm, TiO2 in a thickness of 140 nm and Si3N4 in a thickness of 120 nm nm, or - Si3N4 in a thickness of 140 nm, TiO2 in a thickness of 170 nm and Si3N4 in a thickness of 140 nm, or - Si3N4 in a thickness of 165 nm, TiO2 in a thickness of 190 nm and Si3N4 in a thickness of 165 nm, or - Si3N4 in a thickness of 120 nm, TiO2 in a thickness of 140 nm and Si3N4 in a thickness of 120 nm. 6.Glazing unit (1) according to claim 5, further comprising a SiO2 layer with a thickness of approximately 100 nm to approximately 230 nm or from approximately 3 nm to approximately 100 nm as a capping layer completing the layered structure.

7. Glazing unit (1) according to any one of claims 1 to 6, wherein the glazing unit (1) comprises several photonic structures (2a, 2b, 2c), each reflecting a different first partial spectrum.

8. Glazing unit (1) according to any one of claims 1 to 7, wherein the polymer (3) comprises a second structured surface (5) opposite the first structured surface (4) of the polymer (3), or wherein the polymer (3) comprises a second structured surface (5) opposite the first structured surface (4) of the polymer (3), and at least one second photonic structure is disposed on the second structured surface (5). 9.Glazing unit (1) according to any one of claims 1 to 8, wherein the first surface areas have a first photonic structure (2) and second surface areas have a second photonic structure or no photonic structure. 10.A method for producing a glazing unit (1) for aesthetic design, comprising or consisting of at least one photonic structure (2) and a polymer (3), characterized by the following steps: providing a polymer (3), producing a first structured surface (4) on the polymer (3), and applying the photonic structure (2) to the first structured surface (4), such that it is configured to reflect a first partial spectrum of incident electromagnetic radiation and to transmit a second partial spectrum of incident electromagnetic radiation, characterized in that the reflected proportion corresponds to a higher harmonic and is in the visible spectral region. 11.A method according to claim 10, wherein the photonic structure (2) is applied to the first structured surface (4) of the polymer (3) by sputtering and / or the first structured surface (4) is produced by sandblasting, pickling, stamping, casting, or laminating.

12. A method according to any one of claims 10 to 11, wherein a mask is generated on the first structured surface (4) before the application of the photonic structure (2), and is removed after the application of the photonic structure (2).

13. A method according to claim 12, wherein the mask is generated by printing. 14.Solar module, comprising at least one glazing unit (1) according to any one of claims 1 to 9, at least one first inset film (7a), at least one solar cell (8), at least one second inset film (7b), and at least one backside sheet (9).

15. Solar thermal collector with a glazing unit according to any one of claims 1 to 9.

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