Optoelectronic component and method for detecting a defect in an optoelectronic component

Abstract

Optoelectronic component (100) comprising - an organic functional layer stack (2) arranged between a first and a second electrode (1, 7), - an encapsulation element (3) which is arranged above the second electrode (7) and, in its functionally determined application, forms a seal against environmental influences (U) for at least the organic functional layer stack (2) and an indicator element (4), - wherein the indicator element (4) is arranged between the second electrode (7) and the encapsulation element (3), wherein the indicator element (4) has at least a first component (A) and a second component (B) which are capable of forming an indicator component (AB), wherein in the case of the functionally determined application of the encapsulation element (3), the formation of the indicator component (AB) is at least kinetically inhibited, wherein in the case of at least one defect (5) in the encapsulation element (3), environmental influences (U) are in contact with the indicator element (4), so that a start reaction (6) takes place with the release of a first energy (dH1), wherein the first energy (dH1) of the start reaction activates the formation of the indicator component (AB), and where the first component (A) is zinc and the second component (B) is iodine.

Description

[0001] The invention relates to an optoelectronic component. Furthermore, the invention relates to a method for detecting a defect in an optoelectronic component.

[0002] The following publications relate to optoelectronic components: US 2009 / 0 289 202 A1, DE 10 2007 027 473 A1, EP 2 131 424 B1, US 2014 / 0 374 712 A1, DE 10 2015 205 503 A1.

[0003] In optoelectronic components, especially organic light-emitting diodes (OLEDs), local defects in an encapsulation element appear in the form of dark spots. These dark spots are visually disturbing, but due to their size, they are sometimes not electrically detectable.

[0004] One object of the invention is to provide an optoelectronic component that easily indicates defects. In particular, one object is to easily detect the defects visually and / or electrically. Furthermore, the invention is to provide a method for detecting defects in an optoelectronic component that is fast and / or efficient.

[0005] These objects are achieved by an optoelectronic component according to independent claim 1. Advantageous embodiments and refinements of the invention are the subject of the dependent claims. Furthermore, these objects are achieved by a method for detecting a defect in an optoelectronic component according to independent claim 15.

[0006] The optoelectronic component comprises an organic functional layer stack. The organic functional layer stack is arranged between a first and a second electrode. The optoelectronic component comprises an encapsulation element. The encapsulation element is arranged above the second electrode. In its functionally determined application, the encapsulation element forms a seal against environmental influences for at least the organic functional layer stack and an indicator element. The indicator element is arranged between the second electrode and the encapsulation element. The indicator element comprises or consists of at least a first component A and a second component B. The first component A and the second component B are capable of forming an indicator component AB.In the case of a functionally specific application of the encapsulation element, the formation of the indicator component is at least kinetically inhibited. In the case of at least one defect in the encapsulation element, environmental influences come into contact with the indicator element, so that an initiation reaction occurs with the release of an initial energy. The initial energy of the initiation reaction activates the formation of the indicator component.

[0007] Alternatively or additionally, the indicator component can be arranged on a substrate, in particular between the substrate and the first electrode.

[0008] The fact that a layer or element is arranged or applied "on" or "over" another layer or element can mean here and below that one layer or element is arranged in direct mechanical and / or electrical contact with the other layer or element. Furthermore, it can also mean that one layer or element is arranged indirectly over another layer or element. In this case, further layers or elements can be arranged between one and the other layer or between one and the other element.

[0009] The fact that a layer or element is arranged "between" two other layers or elements can mean here and below that one layer or element is arranged in direct mechanical and / or electrical contact or in indirect contact with one of the two other layers or elements. In the case of indirect contact, further layers and / or elements can be arranged between one and at least one of the two other layers or elements.

[0010] According to at least one embodiment, the optoelectronic component is an organic light-emitting component. In particular, the optoelectronic component is an organic light-emitting diode (OLED). In particular, the component is operable, i.e., capable of and configured to emit radiation.

[0011] The optoelectronic component comprises an organic functional layer stack. In particular, the organic functional layer stack comprises organic polymers, organic oligomers, organic monomers, organic small non-polymeric molecules (“small molecules”), or combinations thereof. The organic functional layer stack can comprise at least one organic light-emitting layer. In addition to the one organic light-emitting layer, the organic functional layer stack can comprise at least one functional layer embodied as a hole-transport layer to enable effective hole injection into at least one of the light-emitting layers. Materials that may prove advantageous for a hole-transport layer include, for example, tertiary amines, carbazole derivatives, camphorsulfonic acid-doped polyaniline, or polystyrenesulfonic acid-doped polyethylenedioxythiophene.The organic functional layer stack may further comprise at least one functional layer configured as an electron-transport layer. In general, in addition to the at least one organic light-emitting layer, the organic functional layer stack may comprise further layers selected from hole-injection layers, hole-transport layers, electron-injection layers, electron-transport layers, hole-blocking layers, and electron-blocking layers.

[0012] The optoelectronic component has at least two electrodes. The organic functional layer stack is arranged between the two electrodes.

[0013] According to at least one embodiment, at least one of the electrodes is transparent. "Transparent" refers here and below to a layer that is permeable to visible light. The at least transparent layer can be clearly translucent or at least partially light-scattering and / or partially light-absorbing, so that the transparent layer can, for example, also be diffusely or milkily translucent. Particularly preferably, a layer referred to as transparent here is as translucent as possible, so that, in particular, the absorption of light or radiation generated during operation of the component is as low as possible.

[0014] According to at least one embodiment, both electrodes are transparent. The light generated in the organic functional layer stack can then be emitted in both directions, i.e., through both electrodes. If the optoelectronic component has a substrate, this means that light can be emitted both through the substrate, which is then also transparent, and in the direction away from the substrate. Furthermore, in this case, all layers of the optoelectronic component can be transparent, so that the optoelectronic component forms a transparent OLED.Furthermore, it may also be possible for one of the two electrodes between which the functional layer stack is arranged to be non-transparent and preferably reflective, so that the light generated in the organic functional layer stack can only be emitted in one direction through the transparent electrode. If the electrode arranged on the substrate is transparent and the substrate is also transparent, this is referred to as a bottom emitter, whereas if the electrode arranged facing away from the substrate is transparent, this is referred to as a top emitter.

[0015] According to at least one embodiment, one electrode is transparent and the other electrode is reflective, so that the radiation generated in the optoelectronic component is coupled out in the direction of the transparent electrode.

[0016] A transparent conductive oxide, for example, can be used as a material for a transparent electrode. Transparent conductive oxides (TCOs) are 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, SnO2, or In2O3, ternary metal-oxygen compounds, such as Zn2SnO4, CdSnO3, ZnSnO3, MgIn2O4, GaInO3, Zn2In2O5, or In4Sn3O, are also suitable. 12 or mixtures of different transparent conducting oxides belong to the group of TCOs. The TCOs do not necessarily correspond to a stoichiometric composition and can also be p- or n-doped. In particular, the transparent material is indium tin oxide (ITO).

[0017] Furthermore, a transparent electrode can also comprise a metal layer with a metal or an alloy, for example, with one or more of the following materials: silver, platinum, gold, magnesium, or an alloy of silver and magnesium. Other metals are also possible. The metal layer has such a small thickness that it is at least partially transparent to the light generated by the organic functional layer stack, for example, a thickness of less than or equal to 50 nm.

[0018] As a material for a reflective electrode, for example, a metal can be used, which can be selected from aluminum, barium, indium, silver, gold, magnesium, calcium, and lithium, as well as compounds, combinations, and alloys thereof. In particular, a reflective electrode can comprise silver, aluminum, or alloys thereof, for example, Ag:Mg, Ag:Ca, Mg:Al.

[0019] In particular, the electrodes can be nanostructured electrodes, for example electrodes with nanowire structures such as silver nanowires, or made of graphene.

[0020] In particular, the first electrode can be designed as an anode, in which case the second electrode can be designed as a cathode. Alternatively, the first electrode can be designed as a cathode, in which case the second electrode can be designed as an anode.

[0021] The electrodes may also comprise a combination of at least one or more TCO layers and at least one or more metal layers.

[0022] According to at least one embodiment, the optoelectronic component comprises a substrate. In particular, one of the two electrodes, in particular the first electrode, is arranged on the substrate. The substrate can, for example, comprise one or more materials in the form of a layer, a plate, a film, or a laminate, selected from glass, quartz, plastic, metal, silicon, and wafer. In particular, the substrate comprises or consists of glass.

[0023] According to at least one embodiment, the optoelectronic component is configured to emit at least radiation from the visible wavelength range. In particular, the radiation has a wavelength or a wavelength maximum that has a value between 400 nm and 800 nm, for example, 420 nm to 680 nm.

[0024] The optoelectronic component comprises an encapsulation element. The encapsulation element is arranged above the second electrode. In its functionally determined application, the encapsulation element forms a seal against environmental influences for at least the organic functional layer stack and the indicator element. In other words, the encapsulation element is a hermetic seal against environmental influences, for example, against moisture and / or oxygen and / or other corrosive substances, such as hydrogen sulfide. In particular, the encapsulation element protects the at least one organic functional layer stack, the indicator element, and the electrodes from the environment, thus preventing degradation and / or corrosion.

[0025] The encapsulation element is preferably formed in the form of a thin-film encapsulation. The encapsulation element can comprise one or more thin layers, which are applied, for example, by means of an atomic layer deposition process and which comprise, for example, one or more of the materials aluminum oxide, zinc oxide, zirconium oxide, titanium oxide, hafnium oxide, lanthanum oxide, and tantalum oxide. The encapsulation element can further comprise, for example, on a thin-film encapsulation, mechanical protection in the form of a plastic layer and / or a laminated glass layer and / or a laminated metal layer, whereby, for example, scratch protection can be achieved. Alternatively, instead of a thin-film coating (TFR), a cavity encapsulation made of SiNCO x and / or ATO. In particular, SiNCO x a mixture of SiN, SiO x and SiC in any composition and sequence. ATO stands for AlO xand TiO x in any thickness and order.

[0026] Alternatively, the encapsulation element can be formed, for example, in the form of a glued-on glass cover. In particular, the glass cover or the glass is arranged on a thin-film encapsulation by means of an adhesive or an adhesive layer.

[0027] According to at least one embodiment, the encapsulation element has a layer thickness of 20 nm to 5 µm, for example 20 nm to 30 nm. Especially for SiNCO x For a thickness of up to 10 µm, the encapsulation element in particular has a layer thickness of 0.5 µm to 5 µm, for example, 1 µm to 3 µm. Specifically for ATO, the encapsulation element in particular has a layer thickness of 40 nm to 60 nm, for example, 50 nm.

[0028] An indicator element is arranged between the second electrode and the encapsulation element. In particular, the indicator element is arranged in direct electrical and / or mechanical contact with the second electrode and the encapsulation element.

[0029] According to at least one embodiment, the indicator element is formed as a layer system. In particular, the indicator element has or consists of a layer of at least a first component A and a layer of a second component B. The layer of at least the first component A can consist of the first component or comprise further materials, for example a matrix material. The layer of at least the second component B can consist of the second component or comprise further materials, for example a matrix material. The layer of the first component A and the layer of the second component B are in particular arranged in direct mechanical and / or electrical contact with one another.

[0030] The layer thickness of the layer of at least the first component and the layer thickness of the layer of at least the second component can each be 5 nm to 10 nm.

[0031] Alternatively, the indicator element can have at least one layer in which the first and second components are mixed. In other words, the indicator element has the first and second components as a mixture. The mixture can be homogeneous or inhomogeneous. In addition to the first and second components, the mixture can comprise further materials, for example a matrix material. In particular, the first and / or the second component are embedded or contained in the matrix material. In particular, the matrix material is an oxide of a transition metal, a resin and / or a polymer, in particular a synthetic polymer, such as polyurethane. In particular, the matrix material can fulfill the function of a binder, i.e. bind the first and / or second components and / or act as moderators.

[0032] The matrix material can be chemically inert, meaning it does not react with the first and / or second component.

[0033] For example, the matrix material is formed from aluminum oxide nanoparticles.

[0034] According to at least one embodiment, the first and / or second components in the indicator element are formed as a solid and / or paste. The indicator element can be applied in a laterally structured manner between a contact layer and a sealing layer, in particular the encapsulation element.

[0035] According to at least one embodiment, the first and / or second component is contained in the indicator element in a proportion of 5 wt% to 95 wt%, in particular between 40 wt% and 80 wt%, for example 50 wt%. The remaining portion in the indicator element can be fillers.

[0036] According to at least one embodiment, the indicator element covers the main radiation surface of the organic functional layer stack. In particular, the indicator element covers the main radiation surface and the radiation side surfaces of the organic functional layer stack in a form-fitting manner.

[0037] According to at least one embodiment, the indicator element covers both the side surfaces and the surface of the second electrode directly and in a form-fitting manner.

[0038] The indicator element is particularly designed to make a defect in the encapsulation element visually and / or electrically identifiable. The first component and / or the second component have a different visual appearance to an external observer and / or a different current-voltage characteristic compared to the indicator component. Thus, in the event of a defect, in particular a local defect, in the encapsulation element, the first and second components combine to form the identifiable indicator component. This makes the defect in an encapsulation element easily detectable.

[0039] The first component and the second component are capable of forming an indicator component. In the case of a functionally specific application, i.e., when the seal of the encapsulating element is intact against environmental influences, the formation of the indicator component is at least kinetically inhibited. This specifically means that the reaction of the first and second components to form the indicator component is possible, but does not occur quickly enough.

[0040] Alternatively or additionally, the formation of the indicator component may be thermodynamically inhibited in the case of a functionally specific application of the encapsulation element. This means, here and in the following, that the reaction proceeds rapidly, but the equilibrium lies primarily on the starting materials side, i.e., on the side of the first and second components.

[0041] In particular, the first component and the second component are different materials.

[0042] In other words, a mixture or layer sequence of the first and second components is provided that, without environmental influences, has such a high activation energy that a self-reaction between the two components does not occur or occurs extremely slowly under operating conditions, especially at the temperature prevailing in the component. Thus, the component remains unchanged.

[0043] In the case of at least one defect in the encapsulation element, the indicator element comes into contact, in particular direct mechanical contact, with environmental influences, for example, with air and / or water. This initiates a starting reaction that releases a first energy. In particular, the first energy of the starting reaction is used to activate the formation of the indicator component. In other words, the starting reaction provides a first energy, in particular a first free reaction enthalpy, which is greater than the activation energy of the reaction between the first and second components. This allows a further reaction to occur, in which the indicator component AB is formed.

[0044] In particular, when defects occur, environmental influences such as air and water penetrate the indicator element and cause a rapid chemical reaction. This process can be multi-stage.

[0045] According to at least one embodiment, the organic functional layer stack has a main radiation surface. In particular, the organic functional layer stack is configured to emit radiation via this main radiation surface. In particular, the indicator element completely covers the organic functional layer stack. In the case of at least one local defect in an encapsulation element, environmental influences are at least locally in contact with the indicator element. This triggers at least a local initial reaction, which releases the first energy. The first energy generates a further reaction, forming the indicator component AB. The indicator component is arranged downstream of the main radiation surface over the entire surface. At least the local defects in the encapsulation element are electrically detectable by the formation of the indicator component AB, and thus the defective component can be identified.

[0046] According to at least one embodiment, the starting reaction takes place by reaction of the first and / or second component or by reaction of at least one third component different from the first and second component with environmental influences, such as air and water.

[0047] According to at least one embodiment, the initiation reaction is a catalysis that activates or generates the formation of the indicator component. Additionally, after the formation of the indicator component has been activated by the catalysis, the formation of the indicator component can occur without an initiation reaction.

[0048] According to at least one embodiment, the catalysis is proton catalysis, and the catalyst is water. In particular, in proton catalysis, water can be the initiator or catalyst, which reduces the activation energy of the reaction between the first and second components. Thus, in the event of a defect in the encapsulation element, the kinetic inhibition of the reaction between the first and second components to form the indicator component is overcome. The indicator component is formed.

[0049] Alternatively, the starting reaction can be an oxidation reaction and / or a reduction reaction and / or a redox reaction. In particular, the starting reaction is an oxidation and / or reduction of at least one of the first and second components A, B with environmental influences U, forming a first energy dH1 and a by-product AU or BU, wherein the first energy dH1 activates the formation of the indicator component AB. The following applies: A+U→AU+dH1 or B+U→BU+dH1 A+B+dH1→AB

[0050] According to at least one embodiment, after the initial reaction has taken place, the formation of the indicator component from the first component and the second component occurs independently of the presence of environmental influences. This is particularly the case when the initial energy is greater than the required activation energy. The initial reaction can only serve as an initiation and provides the initial amount of energy that activates the subsequent reaction to form the indicator components.

[0051] According to at least one embodiment, the reaction for forming the indicator component proceeds at an accelerated rate. This results in accelerated growth at the defects in the encapsulation, which is detectable by the formation of the indicator component. In particular, the defects can be electrically detectable by means of a current-voltage characteristic curve or visually visible.

[0052] The first component is zinc, and the second component is iodine. Specifically, the first and second components are present as a mixture.

[0053] In other words, this is an indicator element that has a first component of zinc and a second component of iodine. Zinc and iodine coexist in a functionally specific application of the encapsulation element. The reaction is kinetically inhibited, which can be seen in the stable dry mixture. If this mixture of zinc and iodine comes into contact with environmental influences, such as water, a redox reaction occurs according to the equations: Zn + 2H + → Zn 2+ + 2[H] I: I2 + 2[H] → 2HI II: Zn + 2HI → ZnI2 + 2[H] III: Zn + I2 → ZnI2 + dH1 IV:

[0054] Water contains some protons, which initially react with the base zinc (Reaction I). Hydrogen is formed in "nascent state" (symbol [H]). This refers to hydrogen atoms or hydrogen radicals that react with iodine immediately after their formation (Reaction II). This forms hydrogen iodide, whose protons react with zinc (Reaction III). Zinc iodide is formed.

[0055] This is a proton catalysis with a reduced activation energy. Reaction IV occurs, resulting in the first energy dH1.

[0056] This first energy can be used to activate the formation of the indicator component AB. In particular, the first energy is an exothermic reaction enthalpy.

[0057] According to at least one embodiment, the first and second components are independently selected from a group comprising Mg, Ca, Al, Ti, Zr, Fe, B, Si, FeOx, MgOx, CuOx, WOx, MoOx, MnOx, CuOx, BiOx, ZnOx, SnOx, nitrates, chlorates, perchlorates, peroxides, dinitramines, chromates, permanganates, ammonium nitrate, ammonium perchlorate, ammonium dinitramide, sodium percarbonate, 2,2,6,6-tetramethylpiperidinyloxyl and N-methylmorpholine N-oxide, MgH2, ZrH2, LiAlH, calcium silicide, arsenic sulfide, antinomy sulfide, bismuth sulfide, and nitrogen-containing compounds. A nitrogen-containing compound is, in particular, hexamine.

[0058] The index x of the respective compounds can, in particular, designate the compound in the possible oxidation states. For example, CuOx designates copper(I) oxide (Cu2O) and / or copper(II) oxide (CuO). Alternatively, x can be 1, for example, when magnesium oxide (MgO) is meant.

[0059] According to at least one embodiment, the first component and the second component have different redox potentials. In particular, a mixture of metals, such as magnesium, calcium, aluminum, titanium, and metal oxides, such as iron oxide, magnesium oxide, and / or copper oxide, is selected as the first and second components according to the electrochemical series.

[0060] The standard potentials are referenced to the standard hydrogen electrode. The more positive the potential, the more noble the metal. Metals with a negative potential are called base metal. In other words, the more noble metal exists, for example, as an oxide before the reaction. In the redox reaction, the less noble metal is oxidized, while the more noble metal is reduced.

[0061] For example, the starting reaction can be an oxidation of the less noble metal with atmospheric oxygen.

[0062] According to at least one embodiment, an oxidizing agent can be used as the first and / or second component. The oxidizing agent can be organic or inorganic. In particular, the oxidizing agent is selected from a group comprising nitrates, chlorates, perchlorates, peroxides, dinitramines, chromates, permanganates of alkali and / or alkaline earth metals, WOx, MoOx, MnOx, CuOx, FeOx, BiOx, ZnOx, SnOx, ammonium nitrate, ammonium perchlorate, ammonium dinitramide, sodium percarbonate, 2,2,6,6-tetramethylpiperidinyloxyl, and N-methylmorpholine-N-oxide. In particular, 2,2,6,6-tetramethylpiperidinyloxyl can also be used as an oxidation catalyst. In particular, magnesium and / or aluminum or an alloy thereof can be used as the first and / or second and / or third component.

[0063] Alternatively or additionally, materials selected from a group comprising titanium, zirconium, iron, boron, silicon, magnesium hydride, zirconium hydride, lithium aluminum hydride, calcium silicide, arsenide sulfide, antimony sulfide, bismuth sulfide, nitrogen-rich compounds such as hexamine, organometallics, graphite and carbon may be used for the initiation reaction.

[0064] The inventors have recognized that by using an indicator element in an optoelectronic component capable of forming the indicator component, small and / or local defects in an encapsulation element can be easily detected. The indicator component forms, in particular, throughout the entire indicator element, so that it can be detected quickly and easily. The accelerated production of the indicator component leads to the rapid detection of defects in the encapsulation element during the manufacture of the component, so that the defective components or elements can be selected out during production. In particular, it is also possible to restrict the detection to individual regions by lateral structuring of the material mixture. In particular, dark signatures can be generated in this way.

[0065] In particular, the indicator element is arranged over the entire main radiating surface of the organic functional layer stack, so that in the event of a defect in the encapsulation element, the formation of the indicator component extends over the entire luminous surface. Alternatively, more than 80% of the luminous surface, for example, 95% of the luminous surface, is covered by the indicator component. This allows a defective component to be easily identified.

[0066] The invention further relates to a method for producing an optoelectronic component. Preferably, the optoelectronic component is produced. The same definitions and explanations as above for the optoelectronic component also apply to the method, and vice versa.

[0067] According to at least one embodiment, the method comprises the method steps: A) Providing a substrate, B) Applying a first electrode to the substrate, C) applying at least one organic functional layer stack to the first electrode, D) Applying a second electrode to the organic functional layer stack, E) applying an indicator element to the second electrode, and F) Applying an encapsulation element to the indicator element.

[0068] According to at least one embodiment, the indicator element is produced by vapor deposition of a first component and / or a second component. Alternatively, the indicator element can be printed. In particular, the first and second components in the indicator element can have any desired mixing ratio, for example, a 1:1 ratio. In particular, the indicator element is produced under an inert atmosphere, for example, in a glove box under nitrogen.

[0069] The invention further relates to a method for detecting defects in an optoelectronic component. Preferably, defects are detected in the optoelectronic component described above. The same definitions and explanations as mentioned above for the optoelectronic component or for the method for producing an optoelectronic component also apply to the method for detecting at least one defect in an optoelectronic component, and vice versa.

[0070] In particular, the method detects a local defect. Detection is carried out by an initial reaction and a subsequent reaction to form the indicator component.

[0071] According to at least one embodiment, the method for detecting a defect in an optoelectronic component comprises the steps: A) Providing an optoelectronic component, in particular an optoelectronic component as described above, and B) optical and / or electrical detection of the defect, in particular the local defect, by formation of the indicator component.

[0072] In other words, an otherwise undetectable local defect in an encapsulation element can be easily detected by the formation of the indicator component, since in particular the indicator component forms over the entire surface of the indicator element according to the domino principle.

[0073] Further advantages, advantageous embodiments and further developments emerge from the exemplary embodiments described below in conjunction with the figures.

[0074] They show: the Fig. 1 and Fig. 2 each shows a schematic side view of an optoelectronic component according to an embodiment, the Fig. 3A to 3C each show a schematic side view of an indicator element according to an embodiment, and the Fig. 4A to 4C and 5A to 5C each show the energetic conditions in the indicator element according to an embodiment.

[0075] In the exemplary embodiments and figures, identical, similar, or similarly functioning elements may be provided with the same reference numerals. The illustrated elements and their relative sizes are not to be considered to scale. Rather, individual elements such as layers, components, structural elements, and regions may be exaggerated for clarity and / or clarity.

[0076] The Fig. 1 shows a schematic side view of an optoelectronic component according to one embodiment. The optoelectronic component 100 is, in particular, an organic light-emitting diode (OLED). The optoelectronic component 100 comprises a substrate 11. The substrate 11 may be made of glass, for example. A first electrode 1 may be arranged downstream of the substrate 11. In particular, the first electrode 1 is transparent and comprises ITO. The first electrode 1 may further comprise or consist of thin metal layers, metallic network structures, or graphene.

[0077] In particular, the component 100 is according to the Fig. 1 is designed as a bottom emitter, thus emitting radiation via the first electrode 1 and the substrate 11. An electrical contact lead 10 is arranged downstream of the first electrode 1.

[0078] The electrical contact lead 10 can be transparent or non-transparent. For example, the electrical contact lead 10 can comprise a metal or an alloy. In particular, the electrical contact lead 10 comprises an alloy of molybdenum and aluminum, or silver and magnesium, or chromium and aluminum. The electrical contact lead 10 can also be formed as a layered structure. For example, the electrical contact lead 10 can comprise or consist of a layer system of molybdenum / aluminum / molybdenum, or chromium / aluminum / chromium, or silver / magnesium, or aluminum.

[0079] An organic functional layer stack 2 is arranged downstream of the first electrode 1. A second electrode 7 is arranged downstream of the organic functional layer stack 2. The second electrode 7 can be reflective, for example made of aluminum. The first and second electrodes 1, 7 can be electrically insulated by insulating layers 9. For example, the insulating layer 9 is made of polyimide. The insulating layer 9 can also be omitted (not shown here). An encapsulation element 3 is arranged above the second electrode 7. In its functionally determined application, the encapsulation element 3 forms a seal against environmental influences U for at least the organic functional layer stack 2 and an indicator element 4. The indicator element 4 is arranged between the second electrode 7 and the encapsulation element 3.

[0080] The encapsulation element 3 has, in particular, a thin-film coating (TFE, 33). Alternatively, the thin-film coating can be a cavity encapsulation. For example, the thin-film coating can be made of SiNCO x and ATO. The encapsulation element 3 may further comprise a glass layer or a glass substrate 34. The glass substrate 34 may be applied to the thin-film coating 33 by means of an adhesive 32. The adhesive may also be formed as an adhesive layer.

[0081] The indicator element 4 has at least a first component A and a second component B. In particular, the first component A and the second component B differ from one another. The first component A and the second component B can be dispersed in a matrix material 8 (not shown here). Alternatively, the two components A and B can each be formed as a layer and arranged directly on top of one another. The two components A and B are capable of forming an indicator component AB, i.e., they are reactive components. In the case of the functionally determined application of the encapsulation element 3, i.e., when the encapsulation element forms a hermetic seal against environmental influences U, the formation of the indicator component AB from the two components A and B is kinetically inhibited.In other words, the component mixture or the component layer sequence comprising the first and second components A and B has such a high activation energy that a self-reaction does not occur or occurs extremely slowly under operating conditions, in particular the temperature. For example, the reaction can be an inhibited redox reaction. Thus, in a functional encapsulation element 3, both components A and B are present in the indicator element 4.

[0082] The Fig. 2 shows a schematic side view of an optoelectronic component 100 according to an embodiment. The optoelectronic component 100 of Fig. 2 differs from the optoelectronic component 100 of Fig. 1 in that the encapsulation element 2 has at least one local defect 5. In particular, the defect 5 is arranged in the thin-film coating 33. In addition, the defect 5 can extend beyond the adhesive 32 and the glass substrate 34. This allows environmental influences U, in particular air, water, and / or acidic gases, to reach the indicator element 4 and react with the first component A and / or the second component B and / or a third component C, inducing a starting reaction 6. A first energy dH1 is released by the starting reaction 6. In particular, the first energy dH1 is an exothermic reaction enthalpy. The starting reaction 6 thus produces enough energy to overcome the kinetic inhibition to the formation of the indicator component AB, i.e., the activation energy. This is followed by the formation of the indicator component AB from the first component A and the second component B.In particular, the first and second components A, B differ optically and / or electrically from the indicator component AB.

[0083] The formation of the indicator components AB can be independent of the presence of the environmental influences U. Therefore, no further starting reaction is necessary if the first energy dH1 is greater than the required activation energy between the reaction partners of the first component A and the second component B. Thus, the indicator element 4 of the component 100 of the Fig. 2 compared to the component 100 of the Fig. 1 the indicator component AB, while the indicator element 4 of the Fig. 1 has the first and second components A, B.

[0084] The Fig. 3A to 3C each show a schematic side view of an indicator element 4 according to an embodiment. The indicator elements 4 of Fig. 3A and Fig. 3B can each be part of an optoelectronic component according to Fig. 1. The indicator element 4 of the Fig. 3C can be part of an optoelectronic component according to the Fig. 2 be.

[0085] The Fig. 3A shows the indicator element 4, which has a layer system. The indicator element 4 comprises at least one layer of the first component A and one layer of the second component B. Alternatively, the first component A in the first layer and the second component B in the second layer can each be dispersed in a matrix material 8 (not shown here). In particular, the first component A and the second component B are arranged in direct contact with one another, so that they are capable of reacting and forming the indicator component AB.

[0086] The Fig. 3B shows a schematic side view of an indicator element 4 in which the first component A and the second component B are dispersed in a matrix material 8. The matrix material is, in particular, non-reactive, for example, an unreactive filler material made of aluminum oxide or resin.

[0087] The Fig. 3C differs from the indicator elements 4 of the Fig. 3A and Fig. 3B in that the indicator element 4 of the Fig. 3C, the indicator component AB is included. The indicator element 4 is a component of an optoelectronic component 100 that has a defect, in particular a local defect, in the encapsulation element 3. In particular, the indicator component AB is arranged within the entire indicator element 4. In particular, the indicator element 4 is arranged over the entire organic functional layer stack 2.

[0088] The Fig. 4A to 4C each show an energy profile of a possible chemical reaction in the indicator element 4. In each case, the energy E is shown as a function of the reaction coordinate RK.

[0089] The Fig. Figure 4A shows the energy profile of the starting materials, i.e., the first and second components A and B. In order for the first component A and the second component B to react with each other, they must first be "excited." Therefore, each particle must be assigned a certain amount of energy, the activation energy E a This puts it into an unstable transition state (shown here by the curve maximum), from which the reaction continues to the reaction product, the indicator component AB. Fig. Figure 4A shows the energy profile for an exothermic reaction. Alternatively, the reaction could also be endothermic.

[0090] The energy difference between the reactants and products is the reaction enthalpy dH or dH1. Before this is released, the activation energy E a Starting from the transition state, the sum of the energies from dH1 + E a submitted.

[0091] The diagram shows that a higher activation energy is required for the reverse reaction, since the transition state is further away from the products by dH1. The reaction coordinate RK in this diagram symbolizes the reaction progression from the reactants to the products.

[0092] The Fig. Figure 4A shows that a high activation energy E a This means that in the case of a functionally determined application of the encapsulation element, a reaction A + B → AB is kinetically inhibited under operating conditions. The following applies: dH1 > E a .

[0093] If the encapsulation element has at least one defect, for example in the thin-film coating 33, environmental influences U can penetrate to the indicator element 4. In particular, environmental influences U, such as water, are in direct contact with the indicator element. This can induce a starting reaction 6 ( Fig. 4B). The starting reaction 6 can, for example, be catalysis. In particular, the starting reaction 6 is proton catalysis, with the catalyst being water.

[0094] The catalyst reduces the activation energy E a , so that the indicator component AB is formed from the first and second components A, B under operating conditions. The catalyst does not influence the position of the chemical equilibrium. The equilibrium is only reached more quickly by the catalyst. A first energy dH1, as in Fig. 4B. The first energy dH1 is sufficient to proceed with the reaction A + B → AB, as shown in Fig. 4C. The first energy dH1 of the initial reaction is greater than the activation energy E a , so that the reaction is accelerated. In particular, the reaction of the Fig. 4C can be continued without a starting catalyst. This triggers a reaction that can be detected visually and / or electrically. Defects in the encapsulation element 3 can be detected, allowing defective components 100 to be identified and, if necessary, sorted out.

[0095] The Fig. Figures 5A to 5C each show an energy profile of a chemical reaction in an indicator element 4. The energy E is shown as a function of the reaction coordinate RK. Fig. Figure 5A shows the energy profile of the first component A and the second component B in the case where the encapsulation element 3 has a functionally specific application. Thus, the reaction of the first component A and the second component B to form the indicator component AB is at least kinetically inhibited, since the activation energy E a is so large that no reaction takes place in the component 100 under operating conditions, for example at the existing temperature.

[0096] If the component 100 has a defect 5, for example in the encapsulation element 3, environmental influences U can penetrate into the encapsulation element 3 and to the indicator element 4. At least one component, for example the first component A, can react with the environmental influences U, whereby a compound AU is formed and a first energy dH1 is released. For example, the first component A can be zinc and the second component B iodine. The first component A zinc can be oxidized with atmospheric oxygen to zinc oxide (AU), whereby a first energy dH1 is generated. The reaction of zinc and oxygen is the starting reaction 6 and has an activation energy E a1 on ( Fig. 5B). Alternatively, the initial reaction could also be a reduction or redox reaction.

[0097] The first energy dH1, which is in particular an exothermic reaction enthalpy, can now be used to trigger a further reaction, in particular the reaction of the first component A and the second component B, to the indicator component AB ( Fig. 5C). In other words, the released energy dH1 and dH is greater than the activation energy E a , so that the reaction of the Fig. 5C accelerates. In particular, the reaction of the Fig. 5C can be continued without a starting reaction. Thus, the indicator component AB is formed in the indicator element 4, which, in particular, has a different color compared to the individual components A and B and is thus easily detectable. This allows the defects 5 in the sealing element 3 to be easily identified, and thus the defective component 100 to be sorted out. Sorting out can, in particular, already take place during production.

[0098] The exemplary embodiments described in conjunction with the figures and their features can also be combined with one another according to further exemplary embodiments, even if such combinations are not explicitly disclosed in conjunction with the figures. Furthermore, the exemplary embodiments described in conjunction with the figures can have additional or alternative features according to the description in the general part.

Claims

[1] Optoelectronic component (100) comprising - an organic functional layer stack (2) arranged between a first and a second electrode (1, 7), - an encapsulation element (3) which is arranged above the second electrode (7) and, in its functionally determined application, forms a seal against environmental influences (U) for at least the organic functional layer stack (2) and an indicator element (4), - wherein the indicator element (4) is arranged between the second electrode (7) and the encapsulation element (3), wherein the indicator element (4) has at least a first component (A) and a second component (B) which are capable of forming an indicator component (AB), wherein in the case of the functionally determined application of the encapsulation element (3), the formation of the indicator component (AB) is at least kinetically inhibited, wherein in the case of at least one defect (5) in the encapsulation element (3), environmental influences (U) are in contact with the indicator element (4), so that a start reaction (6) takes place with the release of a first energy (dH1), wherein the first energy (dH1) of the start reaction activates the formation of the indicator component (AB), and where the first component (A) is zinc and the second component (B) is iodine. [2] Optoelectronic component (100) according to claim 1, wherein the first component (A) and / or the second component (B) have a different visual impression for an external observer and / or a different current-voltage characteristic compared to the indicator component (AB), so that in the case of a defect (5) in the encapsulation element (3), the indicator component (AB) is identifiable. [3] Optoelectronic component (100) according to one of the preceding claims, wherein the organic functional layer stack (2) has a main radiation surface (31) which is designed to emit radiation and is completely covered by the indicator element (4), wherein in the case of at least one local defect (5) in the encapsulation element (3), environmental influences (U) are at least locally in contact with the indicator element (4) and the start reaction (6) takes place with the release of the first energy (dH1), wherein the first energy (dH1) generates the formation of the indicator component (AB) in the entire indicator element (4), so that the indicator component (AB) is arranged downstream of the main radiation surface (31) over the entire area. [4] Optoelectronic component (100) according to one of the preceding claims, wherein the starting reaction (6) takes place by reaction of the first and / or second component (A, B) or by reaction of at least one third component (C) different from the first and second component (A, B) with the environmental influences (U). [5] Optoelectronic component (100) according to one of the preceding claims, wherein the starting reaction (6) is a catalysis which activates the formation of the indicator component (AB), wherein after activation of the formation of the indicator component (AB) by the catalysis, the formation of the indicator component (AB) takes place without a starting reaction (6). [6] Optoelectronic component (100) according to the preceding claim, wherein the catalysis is a proton catalysis and the catalyst is water. [7] Optoelectronic component (100) according to one of the preceding claims, wherein the starting reaction (6) is an oxidation reaction and / or reduction reaction of at least the first and / or second component (A, B) with the environmental influences (U) to form the first energy (dH1), wherein the first energy (dH1) activates the formation of the indicator component (AB). [8] Optoelectronic component (100) according to one of the preceding claims, wherein after the start reaction (6) has taken place, the first component (A) and the second component (B) form the indicator component (AB) independently of the presence of environmental influences (U). [9] Optoelectronic component (100) according to one of the preceding claims, wherein the formation of the indicator component (AB) is an accelerated reaction. [10] Optoelectronic component (100) according to one of the preceding claims, wherein the first component (A) and the second component (B) have a different redox potential. [11] Optoelectronic component (100) according to one of the preceding claims, wherein the indicator element (4) is a layer system comprising at least one layer of the first component (A) and one layer of the second component (B), wherein the layers of the first and second components (A, B) are arranged in direct contact with one another. [12] Optoelectronic component (100) according to one of the preceding claims, wherein the indicator element (4) comprises the first and the second component (A, B) as a mixture. [13] Optoelectronic component (100) according to one of the preceding claims, wherein the first and / or second component (A, B) are contained in a matrix material (8), wherein the matrix material (8) is an oxide of a transition metal, a resin and / or a polymer. [14] Optoelectronic component (100) according to one of the preceding claims, wherein the first and / or second component (A, B) has a proportion in the indicator element (4) of 1 ng to 1 mg. [15] Method for detecting a defect (5) in an optoelectronic component (100) comprising the steps: A) providing an optoelectronic component (100) according to at least one of claims 1 to 14, and B) optical and / or electrical detection of the defect (5) by formation of the indicator component (AB).

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