Organic light-emitting device and method for producing an organic light-emitting device

Abstract

comprising organic light-emitting component (100) - a substrate (1), - a first electrode (2) which is arranged above the substrate (1), - at least one organic functional layer stack (5) designed to emit radiation and arranged at least above the first electrode (2), - at least one conductive current expansion structure (3) arranged on the first electrode (2) and facing the organic functional layer stack (5), wherein the conductive current expansion structure (3) comprises at least one metal, wherein the conductive current expansion structure (3) has a layered structure (301, 302, 303) comprising two silver layers (301, 303), wherein the two silver layers (301, 303) are separated from each other by another metal layer (302) formed from a metal, wherein the conductive current expansion structure (3) is coated with an inorganic passivation layer (4), wherein the inorganic passivation layer (4) comprises a sulfide of at least one metal of the conductive current-expansion structure (3), wherein the inorganic passivation layer (4) has a layer structure (401, 402, 403) which, where the silver layers (301, 303) are arranged, has silver sulfide, and where the metal layer (302) is arranged, has a sulfide of the metal, wherein the inorganic passivation layer (4) is either an n- or a p-type semiconductor, such that no current flow occurs between the conductive current expansion structure (3) and the organic functional layer stack (5) via the inorganic passivation layer (4), and - a second electrode (6) arranged above the organic functional layer stack (5).

Description

[0001] The invention relates to an organic light-emitting component. Furthermore, the invention relates to a method for producing an organic light-emitting component.

[0002] Conductive current expansion structures can be applied, for example, to the first electrode of an organic light-emitting device, such as an organic light-emitting diode (OLED), to achieve uniform light emission or a desired light distribution across the luminous area. These conductive current expansion structures typically require an insulating layer, such as an organic non-conductive resist material or a non-conductive oxide or nitride, to ensure that charge carriers are injected into the organic layer stack only via the first electrode and not through the conductive current expansion structures themselves. However, this necessitates an additional process step to apply the insulating layer separately.Furthermore, particularly with organic insulating layers, decomposition products from the manufacturing process can penetrate into areas crucial for the emission properties, such as the organic functional layer stack, thereby reducing the lifespan of the OLED. This can also lead to a narrowing of the luminous area. Additionally, the cross-sectional height can be unfavorable for encapsulation when using an insulating layer made of, for example, a non-conductive resist material.

[0003] The publication DE 10 2008 045 948 A1 describes a method for manufacturing an organic radiation-emitting component and an organic radiation-emitting component.

[0004] Publication US 2013 / 0 078 436 A1 describes a transparent electrode laminate.

[0005] The publication Tadios Tesfu Zeru: “Solid-state electrochemical investigations on micro- and nanostructured Ag2S and Ag2Se”; dissertation; Justus Liebig University Giessen, 2004 describes solid-state electrochemical investigations on micro- and nanostructured Ag2S and Ag2Se.

[0006] Publication EP 2 068 328 B1 describes a spontaneous emission indicator and a transparent conductive film.

[0007] One challenge to be solved is to overcome the aforementioned disadvantages. Another challenge is to provide an organic light-emitting device that is faster, easier, and / or more cost-effective to manufacture.

[0008] This problem or these problems are solved by an organic light-emitting component according to independent claim 1. Advantageous embodiments and further developments of the invention are the subject of the dependent claims. Furthermore, this problem or these problems are solved by a method for producing an organic light-emitting component according to independent claim 11. Advantageous embodiments and further developments of the method are the subject of dependent claims 12 and 13.

[0009] The organic light-emitting device comprises a substrate. A first electrode is arranged above the substrate. Above the first electrode, at least one stack of organic functional layers is arranged, configured for radiation emission. At least one conductive current expander is arranged on the first electrode. The conductive current expander faces the stack of organic functional layers. The conductive current expander comprises at least one metal. The conductive current expander is coated with an inorganic passivation layer. The inorganic passivation layer comprises or consists of a sulfide of the at least one metal of the conductive current expander.The inorganic passivation layer is either an n-type or a p-type semiconductor, so that no current flow, in particular no vertical current flow, occurs between the conductive current-expansion structure and the organic functional layer stack via the inorganic passivation layer. The organic light-emitting device has a second electrode positioned above the organic functional layer stack.

[0010] It is further described that the inorganic passivation layer comprises or consists of a sulfide, selenide, and / or telluride of at least one metal of the conductive current-expansion structure. In particular, the conductive current-expansion structure includes at least one metal or an alloy of at least two metals.

[0011] In particular, the inorganic passivation layer then consists of a sulfide, selenide and / or telluride of the alloy of the conductive current-expansion structure.

[0012] According to at least one embodiment, the conductive current expansion structure is electrically conductive. Preferably, the conductive current expansion structure is metallic.

[0013] Alternatively or additionally, at least one conductive current expansion structure can be arranged between the substrate and the first electrode, i.e., below the first electrode.

[0014] Alternatively or additionally, the organic light-emitting device can have at least one conductive current-expansion structure located at least between one of the organic functional layer stacks and the second electrode. In particular, the conductive current-expansion structure faces the organic functional layer stack.

[0015] According to at least one embodiment, the organic light-emitting component is shaped as an organic light-emitting diode (OLED).

[0016] According to at least one embodiment, the organic light-emitting device comprises a 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 wafer, ceramic, or coated paper. Particularly preferably, the substrate comprises or is made of glass, for example, in the form of a glass layer, glass film, or glass plate.

[0017] According to at least one embodiment, the organic light-emitting device has a first and a second electrode. In particular, at least one electrode can be transparent. Here and in the following, "transparent" refers to a layer that is permeable to visible light. The 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. A layer referred to here as transparent is particularly preferably as light-transmitting as possible, so that, in particular, the absorption of light generated in the organic functional layer stack during operation of the organic light-emitting device is as low as possible.

[0018] Alternatively, both electrodes can be transparent. This allows the radiation generated in the at least one organic functional layer stack to be emitted in both directions, i.e., through both electrodes. If the organic light-emitting device has a substrate, this means that the radiation 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 organic light-emitting device can be transparent, so that the organic light-emitting device forms a transparent OLED.Furthermore, it is also possible that one of the two electrodes between which the organic functional layer stack is arranged is not transparent and preferably reflective, so that the radiation 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, then it is referred to as a bottom emitter, while in the case where the electrode facing away from the substrate is transparent, it is referred to as a top emitter.

[0019] For example, a transparent conductive oxide (TCO Transparent Conductive Oxide), such as ITO, can be used as a material for a transparent electrode.

[0020] Transparent electrically conductive oxides (TCOs) are transparent, electrically conductive materials, typically metal oxides such as zinc oxide, tin oxide, cadmium oxide, titanium oxide, indium oxide, indium tin oxide (ITO), or aluminum zinc oxide (AZO). 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 In₄Sn₃O₄ also belong to this group. 12 or mixtures of different transparent, conductive oxides belong to the group of TCOs. Furthermore, TCOs do not necessarily have a stoichiometric composition and can also be p- or n-doped.

[0021] Furthermore, a transparent electrode can also have a metal layer made of a metal or alloy, for example, 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 is so thin 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.

[0022] A reflective electrode can be made from a metal such as aluminum, barium, indium, silver, gold, magnesium, calcium, or lithium, as well as compounds, combinations, and alloys thereof. In particular, a reflective electrode can consist of silver, aluminum, or alloys containing these metals, for example, Ag:Mg, Ag:Ca, or Mg:Al.

[0023] In particular, the electrodes can be nanostructured electrodes, for example silver nanowires or made of graphene.

[0024] According to at least one embodiment, the first electrode is configured as the anode, and the second electrode is configured as the cathode. Alternatively, the first electrode can be configured as the cathode, and the second electrode is configured as the anode.

[0025] The electrodes can also consist of a combination of at least one or more TCO layers and at least one or more metal layers.

[0026] According to at least one embodiment, at least one organic functional layer stack is arranged above the first electrode and / or the substrate. The fact that a layer or stack is arranged or applied "on" or "over" another layer or stack can mean, here and in the following, that the layer or stack is in direct mechanical and / or electrical contact with the other layer or stack. It can also mean that the layer is arranged indirectly on or over the other layer or stack. In this case, further layers or stacks can be arranged between the layer or stack and the other layer or stack.

[0027] According to at least one embodiment, the organic light-emitting device comprises at least one organic functional layer stack. In particular, the organic light-emitting device comprises exactly one organic functional layer stack. During operation of the organic light-emitting device, radiation is generated in the organic functional layer stack. A wavelength of the radiation or the wavelength maximum is preferably located in the infrared and / or ultraviolet and / or visible spectral range, particularly at wavelengths between and including 420 nm and 680 nm.

[0028] The organic functional layer stack can comprise layers of organic polymers, organic oligomers, organic monomers, small organic nonpolymeric molecules, or combinations thereof. The organic functional layer stack can additionally include further functional layers configured as hole transport layers to enable effective hole injection into the at least one organic functional layer stack. Suitable materials for a hole transport layer include, for example, tertiary amines, carbazole derivatives, camphorsulfonic acid-doped polyaniline, or polystyrenesulfonic acid-doped polyethylene dioxide thiophene. The organic functional layer stack can further comprise at least one functional layer configured as an electron transport layer.In general, the organic functional layer stack can include additional layers selected from hole injection layers, hole transport layers, electron injection layers, electron transport layers, hole blocking layers, and electron blocking layers. In particular, the layers of the organic functional layer stack can be entirely or predominantly organic functional layers. Furthermore, it is also possible for individual layers of the organic functional layer stack to include or be composed of inorganic materials.

[0029] According to at least one embodiment, the organic light-emitting device has at least one conductive current-expansion structure. The conductive current-expansion structure is arranged on the first electrode. In particular, the conductive current-expansion structure is arranged in direct electrical and / or mechanical contact with the first electrode. The conductive current-expansion structure is specifically oriented towards the organic functional layer stack. In other words, the conductive current-expansion structure projects at least partially or completely into the organic functional layer stack. The conductive current-expansion structures that project only at least partially into the organic functional layer stack, also called external conductive current-expansion structures, can serve for direct contact with the second electrode.

[0030] In particular, several conductive current expansion structures, for example eight to 50, can be present in an organic light-emitting device.

[0031] According to at least one embodiment, the conductive current-expansion structure comprises at least one metal. In particular, the metal can form an alloy with at least one other metal. Alloy can also mean that the at least one metal forms a solid solution with other metals, for example, CuInS₂. In particular, any metal can be used for the conductive current-expansion structure. The resulting inorganic passivation layers, for example, the sulfides, selenides, and / or tellurides, should have the property that they can be used as n-type or p-type semiconductors. This can also be achieved, for example, by doping during fabrication.In particular, the metal or alloy of the conductive current-expansion structure is selected from a group comprising silver, aluminum, molybdenum, chromium, copper, magnesium, or an alloy of molybdenum-aluminum (Mo:Al), chromium-aluminum (Cr:Al), silver-magnesium (Ag:Mg), and combinations thereof. The conductive current-expansion structure is particularly preferably formed from silver.

[0032] The conductive current expansion structure can also be a conductive glass, a conductive ceramic, or a highly doped semiconductor. This is particularly the case when the conductive current expansion structure is coated with a metal layer, preferably silver.

[0033] It is further described that the conductive current expansion structure consists of a metal, specifically silver.

[0034] The conductive current expansion structure has a layered structure. The current expansion structure comprises three layers made of two different metals. Specifically, the conductive current expansion structure has a layered structure consisting of two silver layers, separated by another metal layer. This additional metal layer is made of a single metal.

[0035] The conductive current expansion structures can have any desired shape. In particular, when viewed from above on the organic light-emitting device, the conductive current expansion structures can be parallel supply lines. These parallel supply lines can be spaced equally or at different distances from each other. If the supply lines are spaced equally, a uniform radiation distribution or a desired radiation distribution across the luminous surface can be achieved.

[0036] Alternatively or additionally, the conductive current expansion structure can be designed in the form of a rectangle or in a honeycomb shape.

[0037] According to at least one embodiment, the conductive current expansion structure is applied directly to the first electrode, which is preferably transparent. Application can be carried out, for example, by sputtering or physical vapor deposition (PVD).

[0038] According to at least one embodiment, the conductive current expansion structure is coated with an inorganic passivation layer. The conductive current expansion structure has a surface facing away from the substrate and side surfaces. In particular, both the surface and the side surfaces are coated with the inorganic passivation layer. "Coated" here and in the following means that the inorganic passivation layer completely envelops or covers the side surfaces and the surface of the conductive current expansion structure. In particular, the inorganic passivation layer forms a form-fitting envelopment of the surface and side surfaces of the conductive current expansion structure.

[0039] According to at least one embodiment, the inorganic passivation layer directly covers the surface and side faces of the conductive current-expansion structure facing away from the substrate. "Directly" here and in the following means that the inorganic passivation layer is arranged in direct mechanical contact with both the surface and the side faces of the conductive current-expansion structure. Thus, no further layers or elements are arranged between the surface and / or side faces of the conductive current-expansion structure and the inorganic passivation layer.

[0040] According to at least one embodiment, the inorganic passivation layer comprises or consists of a sulfide and / or selenide and / or telluride of the at least one metal or alloy of the conductive current-expanding structure. In particular, the inorganic passivation layer is free of organic resist materials, metal oxides, nitrides, and / or silicon oxide.

[0041] According to at least one embodiment, the inorganic passivation layer is an n-type semiconductor. Alternatively, the inorganic passivation layer is a p-type semiconductor.

[0042] The term "n-type semiconductor" is used here and in the following to refer to an inorganic passivation layer capable of conducting electrons while preventing hole conduction. In other words, the inorganic passivation layer, configured as an n-type semiconductor, acts as a hole-insulating layer. This prevents hole injection from the conductive current-expansion structure into the adjacent hole transport layers and / or hole injection layers and / or the organic functional layer stack.

[0043] The term "p-type semiconductor" here and in the following refers to a type of semiconductor where the inorganic passivation layer conducts holes and prevents electron conduction. The inorganic passivation layer, whether n-type or p-type, prevents current flow, particularly direct and / or vertical current flow, between the conductive current-expansion structure and the organic functional layer stack via the inorganic passivation layer.

[0044] If the inorganic passivation layer is configured as an n-type semiconductor, this means that hole transport from the first electrode (configured as the anode) through the inorganic passivation layer towards the organic functional layer stack is prevented. If the inorganic passivation layer is configured as a p-type semiconductor, this means that electron transport from the first electrode (configured as the cathode) through the inorganic passivation layer towards the organic functional layer stack is prevented.

[0045] According to at least one embodiment, the inorganic passivation layer is produced by sulfidation of the at least one metal of the conductive current expansion structure. In other words, the metal or alloy of the conductive current expansion structure is treated with a sulfur-ion-containing atmosphere, a sulfur-ion-containing solution, and / or a sulfur-ion-containing plasma, such that an inorganic passivation layer comprising or consisting of a sulfide is produced from the metal of the conductive current expansion structure.

[0046] According to at least one embodiment, the first electrode is configured as an anode. In particular, the anode is transparent. The inorganic passivation layer is an n-type semiconductor, thus preventing hole transport from the first electrode through the inorganic passivation layer toward the organic functional layer stack. In other words, the inorganic passivation layer acts as an insulator for the holes emitted by the anode. The inorganic passivation layer is permeable to electrons.

[0047] According to at least one embodiment, the conductive current-expansion structure comprises a metal, preferably silver. The inorganic passivation layer comprises or consists of a metal sulfide, preferably silver sulfide. In particular, the inorganic passivation layer is produced by sulfidation of the metal, preferably silver, of the conductive current-expansion structure. This production can be carried out, for example, using a hydrogen sulfide atmosphere. In particular, the metal, preferably silver, of the conductive current-expansion structure is only superficially sulfidized. This produces an n-type semiconductor, preferably silver sulfide (Ag₂S), which exhibits non-hole-conducting properties. Silver sulfide is a chemical compound from the group of sulfides, which is formed from a chemical reaction of sulfur and silver.

[0048] According to at least one embodiment, the organic light-emitting device is configured to emit the radiation generated by the organic functional layer stack via the first electrode and the substrate. In other words, the organic light-emitting device is configured as a bottom emitter.

[0049] It is further described that the conductive current-expansion structure comprises or consists of a metal, preferably silver. The inorganic passivation layer is produced by telluridization of at least the metal, preferably silver, of the conductive current-expansion structure. In other words, an inorganic passivation layer is produced from the metal, preferably silver, of the conductive current-expansion structure, which comprises or consists of a metal telluride, preferably silver telluride (Ag₂Tr). Silver telluride is a monoclinic crystalline compound from the group of tellurides, which is formed from silver and tellurium in a high-temperature process. Silver telluride is, in particular, an n-type semiconductor. Preferably, the first electrode is configured as the anode.

[0050] According to at least one embodiment, the inorganic passivation layer is produced by selenidizing at least the metal of the conductive current-expansion structure. The inorganic passivation layer then contains or consists of at least one selenide.

[0051] The inventors have recognized that by using an inorganic passivation layer, which is either an n- or p-type semiconductor and comprises a sulfide, selenide, and / or telluride of at least one metal of the conductive current-expansion structure, no restructuring is necessary. Furthermore, the application of the inorganic passivation layer is possible in a simple reactive process step. In particular, the inorganic passivation layer is formed from a silver sulfide, silver selenide, and / or silver telluride, preferably a silver sulfide. Alternatively, the silver sulfide, silver selenide, and / or silver telluride can be additionally n-doped. Silver is the material with the highest known electrical conductivity.This allows for higher conductivity to be achieved with the same layer thickness as with the previously common conductive current expansion structures, which, for example, have a layer structure of chromium, aluminum and chromium, or the layer thickness can be reduced to achieve the same conductivity as the previous layer stack.

[0052] According to at least one embodiment, the first or second electrode is configured as a cathode. The inorganic passivation layer is a p-type semiconductor, thus preventing electron transport from the first or second electrode across the inorganic passivation layer toward the organic functional layer stack. In other words, the first or second electrode is configured as a cathode and is designed to emit electrons toward the organic functional layer stack. Since the inorganic passivation layer is configured as a p-type semiconductor and is therefore permeable only to holes, it acts as an electron-insulating layer. Consequently, no electrons are transported across the inorganic passivation layer into the organic functional layer stack.

[0053] According to at least one embodiment, the second electrode is configured as a cathode. In particular, the organic light-emitting device is configured as a transparent OLED. This means that the radiation generated by the organic functional layer stack is emitted via both the first and second electrodes. The second electrode, in particular, has an inorganic passivation layer that is a p-type semiconductor. Additionally, the first electrode, in particular, has an inorganic passivation layer that is configured as an n-type semiconductor. Thus, the respective passivation layers act as hole or electron insulators, preventing direct current flow through them.

[0054] According to at least one embodiment, the inorganic passivation layer is a mixture of at least two different metal sulfides. In particular, each metal sulfide in the mixture is an n- or p-type semiconductor.

[0055] According to at least one embodiment, the inorganic passivation layer has a thickness between 10 nm and 100 nm, and in particular between 5 nm and 50 nm. In particular, the inorganic passivation layer has a thickness of less than or equal to 10 nm. In particular, the layer thickness is such that tunneling current is prevented. This allows the tunneling current to be suppressed, and at the same time, the conductive current-expansion structures are virtually invisible because the inorganic passivation layer is very thin.

[0056] According to at least one embodiment, the inorganic passivation layer is additionally or alternatively applied to the first electrode and / or the conductive current expansion structure, which is arranged at least outside the organically functional layer stack.

[0057] By using an inorganic passivation layer on conductive current expanders, these structures are virtually invisible compared to polyimide-coated conductive current expanders, as the inorganic passivation layer is applied very thinly. Furthermore, they exhibit reliable insulation against holes and electrons. The inorganic passivation layer is also easy and inexpensive to produce and its properties are highly controllable. The production of an inorganic passivation layer can be easily integrated into existing processes, for example, even when baking out the substrates after cleaning is necessary. Simultaneously, the properties of the first electrode, especially those made of TCO, are also affected, as a lower voltage is required in the organic light-emitting device, resulting in a longer lifetime.

[0058] Since the conductive current expansion structures coated with an inorganic passivation layer are virtually invisible, they can be arranged arbitrarily, for example, to create a desired inhomogeneity. The conductive current expansion structures have a width of 50 µm. A wider resist is not necessary.

[0059] Due to their small size, the conductive current expansion structures coated with an inorganic passivation layer can be arranged very close together. This contributes to the fact that beyond a certain distance, the conductive current expansion structures are no longer perceptible, thus creating a blurring effect between a luminous area and the non-luminous conductive current expansion structure. In particular, conductive current expansion structures can have a width of 1 µm, especially down to a minimum or maximum of 1 µm.

[0060] Furthermore, conductive current expansion structures coated with an inorganic passivation layer provide a more reliable insulation compared to current expansion structures coated by screen printing.

[0061] According to at least one embodiment, the conductive current expansion structure has a surface and side surfaces facing away from the substrate, wherein the inorganic passivation layer directly covers both the surface and the side surfaces.

[0062] It is further described that the conductive current expansion structure has or comprises a metal layer. The conductive current expansion structure has a surface and side faces facing away from the substrate. The metal layer covers, in particular directly, the surface and side faces of the conductive current expansion structure facing away from the substrate. "Directly" here means in direct mechanical contact. The inorganic passivation layer can be generated from the metal layer. In particular, the inorganic passivation layer is generated by sulfidation, telluridization, and / or selenidation of the metal layer and is located at least on the surface and side faces of the conductive current expansion structure or covers them.

[0063] In other words, a metal layer is applied to the conductive current-expansion structure, with the thickness of the metal layer being arbitrarily adjustable. The metal layer shapes both the side faces and the surface of the conductive current-expansion structure. Subsequently, the metal layer can be at least partially sulfidized, telluridized, and / or selenidized, thereby transforming at least partially into an inorganic passivation layer. This allows for the creation of a uniform inorganic passivation layer made from a single material.

[0064] According to at least one embodiment, the inorganic passivation layer has a thickness of less than or equal to 10 nm. Compared to the conventional insulating layer, the inorganic passivation layer is dense at this thickness.

[0065] It is further described that the metal layer contains or consists of silver. The inorganic passivation layer then contains or consists of silver sulfide.

[0066] According to at least one embodiment, the organic light-emitting device has an encapsulation. The encapsulation is preferably applied to the organic light-emitting device in the form of a thin-film encapsulation. In particular, the encapsulation protects the at least one organic functional layer stack and the electrodes from the environment, such as moisture and / or oxygen and / or other corrosive substances. The encapsulation can comprise one or more thin layers, which are applied, for example, by an atomic layer deposition process and which, for example, comprise one or more of the materials aluminum oxide, zinc oxide, zirconium oxide, titanium oxide, hafnium oxide, lanthanum oxide, and tantalum oxide.The encapsulation can also include, for example, a thin-film encapsulation with mechanical protection in the form of a plastic layer and / or a laminated glass layer, which can, for example, provide scratch protection.

[0067] Alternatively, a different encapsulation method is possible, for example, in the form of an adhered glass lid. Specifically, the glass lid or the glass itself is attached to the thin-film encapsulation using an adhesive or bonding layer. Alternatively, instead of a thin-film encapsulation (TFE), cavity encapsulation with getter material can be used.

[0068] The thin-film encapsulation can be structured, for example, as follows: a mixture of silicon nitride, silicon oxide of any oxidation state, and silicon carbide in any desired composition and sequence. Alternatively or additionally, an encapsulation of aluminum oxide of any oxidation state and titanium oxide of any oxidation state in any desired thickness and sequence can be used.

[0069] According to at least one embodiment, the encapsulation has a layer thickness of 20 to 5000 nm. Specifically, for an encapsulation made of silicon nitride, silicon oxide, and silicon carbide, the encapsulation has a layer thickness of 0.5 to 5 µm, for example, 1 nm to 3 µm. For an encapsulation made of aluminum oxide and titanium oxide, a layer thickness of 40 to 60 nm, for example, 50 nm, can be used.

[0070] The invention further relates to a method for producing an organic light-emitting component. Preferably, the method is used to produce an organic light-emitting component. The same definitions and descriptions as above for the organic light-emitting component also apply to the method and vice versa.

[0071] The process for manufacturing an organic light-emitting component comprises the following process steps: A) Providing a substrate, B) Applying a first electrode to the substrate, C) Applying at least one conductive current expansion structure to the first electrode. The conductive current expansion structure has at least one metal component and a surface and side faces facing away from the substrate. D) Selective formation of an inorganic passivation layer at least on the surface and side faces of the conductive current-expansion structure, wherein the inorganic passivation layer comprises or consists of a sulfide of at least one metal of the conductive current-expansion structure. The inorganic passivation layer is either an n-type or a p-type semiconductor such that no current flows between the conductive current-expansion structure and the organic functional layer stack via the inorganic passivation layer. E) Application of an organic functional layer stack at least onto the inorganic passivation layer and at least partially onto the first electrode, F) Applying a second electrode.

[0072] According to at least one embodiment, an additional step C1) is performed before step D). C1) Selective application of a protective layer to areas of the first electrode that are free from the conductive current expansion structure, wherein an additional step D1) is performed after step D): D1) Removal of the protective layer.

[0073] The protective layer ensures that the first electrode is protected during step D), specifically preventing sulfidation, telluridization, or selenidation. The protective layer can be removed by selective etching, ablation, and / or lift-off processes.

[0074] According to at least one embodiment, the sulfidation in step D) is carried out using an atmosphere containing hydrogen sulfide. The hydrogen sulfide atmosphere can be generated, for example, by a hydrogen sulfide solution. In particular, the hydrogen sulfide solution must contain at least 99% hydrogen sulfide. The hydrogen sulfide atmosphere can be generated, for example, in a desiccator. Alternatively, the hydrogen sulfide atmosphere can also be generated in a process chamber. In particular, the process chamber should be sealed off from the environment to prevent health risks from hydrogen sulfide.

[0075] Alternatively, sulfidation in step D) can be carried out using a sulfur-containing solution, in particular a sulfur ion-containing solution. Specifically, step D) is then carried out by immersion. Any sulfur ion-containing solution, such as ammonium sulfide ((NH4)2S), can be used.

[0076] Alternatively or additionally, the conductive current expansion structure, which consists in particular of silver, can be treated for sulfidation using a sulfur-containing plasma, especially a sulfur ion-containing plasma. The sulfur ion-containing plasma is based in particular on gaseous hydrogen sulfide.

[0077] According to at least one embodiment, telluridization is carried out using a tellurium-containing atmosphere, solution and / or plasma.

[0078] According to at least one embodiment, selenidation is carried out using a selenium-containing atmosphere, solution and / or plasma.

[0079] According to at least one embodiment, step C) is carried out in a structured manner. In particular, step C) is carried out using printing processes, such as inkjet printing or engraved printing, or vapor deposition.

[0080] According to at least one embodiment, the conductive current expansion structure is formed in step C) by depositing at least one metal or alloy over the entire surface of the first electrode and subsequently selectively removing the metal or alloy. In other words, the metal or alloy of the conductive current expansion structure is deposited unstructured over the entire surface of the substrate. The conductive current expansion structure is then generated, for example, by etching processes.

[0081] Further advantages, advantageous embodiments and further developments result from the exemplary embodiments described below in conjunction with the figures.

[0082] They show: Fig. 1A and B show a schematic representation of an organic light-emitting component according to a comparative example, Fig. 1C a schematic side view of an organic light-emitting component according to a comparative example, Fig. 2 a schematic top view of an organic light-emitting component according to one embodiment, Fig. 3A a schematic side view of a section of an organic light-emitting component according to a comparative example, Fig. 3B a schematic side view of a section of an organic light-emitting component according to one embodiment, Fig. 4A and Fig. 4B each a schematic side view of a section of an organic light-emitting component according to a comparative example, Fig. 5A to 5F a method for the fabrication of an organic light-emitting device according to a comparative example, Fig. 6A to 6D a method for the production of an organic light-emitting device according to a comparative example, Fig. 7A to 7D a method for producing an organic light-emitting device according to a comparative example and Fig. 8A to 8E describe a method for producing an organic light-emitting device according to a comparative example.

[0083] In the exemplary embodiments and figures, identical, similarly functioning, or comparable elements may be designated with the same reference numerals. The depicted elements and their relative sizes are not to be considered to scale. Rather, individual elements such as layers, components, building elements, and areas may be exaggerated for clarity and / or better understanding.

[0084] The Fig. 1A and Fig. Figure 1B shows a schematic side view of an organic light-emitting device according to a comparative example. The devices each comprise a substrate 1, a first electrode 2, conductive current-expansion structures 3, a second electrode 6, and an organic functional layer stack 5. The electrodes 2 and 6 can be transparent or opaque. In particular, the electrodes 2 and 6 can each be made of ITO, thin metal films, conductive mesh structures, graphene, or combinations thereof. At least the organic functional layer stack 5 is protected from environmental influences by an encapsulation 7. The encapsulation 7 comprises a thin-film coating (TFE) 7-3, an adhesive layer 7-2, and a glass 7-1. Instead of the glass 7-1, a substrate 1, a protective glass, or other protective layers can also be used. Alternatively, cavity encapsulation can be used for the thin-film coating (TFE) 7-3.The component of the . Fig. 1B has an additional contact layer 13. This additional contact layer 13 can also be omitted, allowing for direct contact on the first electrode 2. The conductive current-expansion structures 3 are protected from the subsequently deposited organic functional layer stack 5 by an organic insulating layer 8. The organic insulating layer 8 is, in particular, polyimide and can be applied, for example, using masking processes. The organic insulating layer 8 has a high resist height, in particular 1 µm to 7 µm, and thus extends very far into the organic functional layer stack 5. As a result, the conductive current-expansion structures 3 are visible in a top view of the device 100.Furthermore, the significant height difference at the conductive current expansion structures 3 during the deposition of the organic functional layer stack 5 and / or the encapsulation 5 can lead to short circuits and / or leaks. The organic insulating layer 8, which comprises, in particular, organic compounds, can evaporate during the manufacturing process, allowing decomposition products of the organic compound in the organic insulating layer 8 to enter the organic functional layer stack 5. This can reduce the lifetime of the organic light-emitting device 100.

[0085] Fig. Figure 1C shows a schematic side view of an organic light-emitting component 100 according to a comparative example. Fig. 1C differs from the comparison examples of the Fig. 1A and Fig. 1B by using an inorganic passivation layer 4 instead of an organic insulating layer 8. In particular, the first electrode 2 is configured as an anode, and the inorganic passivation layer 4 is an n-type semiconductor, thus preventing hole transport from the first electrode 2 via the inorganic passivation layer 4 towards the organic functional layer stack 5. The inorganic passivation layer 4 therefore serves to insulate the holes in the conductive current-expansion structures 3 of the anode. The inorganic passivation layer 4 has a thickness of ≤ 10 nm. Specifically, the inorganic passivation layer 4 covers both the side surfaces 3-2 and the surface 3-1 of the respective conductive current-expansion structure 3. Surface 3-1 here refers to the surface facing away from the substrate 1.The inorganic passivation layer 4 is in particular a sulfide, selenide and / or telluride of at least one metal of the conductive current expansion structure 3. In particular, the sulfide formation takes place through a hydrogen sulfide-containing atmosphere, a sulfur ion-containing or sulfur-containing solution or a sulfur ion-containing or sulfur-containing plasma.

[0086] If the conductive current expansion structure 3 preferably contains silver, the inorganic passivation layer 4 is formed from silver sulfide, i.e., Ag₂S. The exposure of the outer contacts can be achieved by ablation or temporary covering, for example, by a protective layer 11. The protective layer 11 can, for example, be a sulfide. By using an inorganic passivation layer 4 in an organic light-emitting device 100, the spacing and / or shape and / or width of the conductive current expansion structures 3 can be varied while still achieving a homogeneous luminous surface. The conductive current expansion structures 3 can be made very narrow and are therefore virtually invisible. This allows for the application of many conductive current expansion structures 3, which contribute to improved uniform emission of the radiation emitted by the organic functional layer stack 5.Coating the conductive current-expansion structures 3 with an inorganic passivation layer 4, which is particularly thin, enables improved deposition of the organic functional layer stack 5. Simultaneously, the first electrode 2, which is formed, for example, from TCO, can be treated, thereby reducing the layer resistance and modifying the work function. Furthermore, the inorganic passivation layer 4 prevents a direct current flow from the first electrode 2 towards the organic functional layer stack 5, for example, into the hole transport layer and / or hole injection layer, which are preferably arranged between the first electrode 2 and the organic functional layer stack 5.

[0087] The Fig. Figure 2 shows a schematic top view of a section of an organic light-emitting component 100 according to one embodiment. Fig. Figure 2 shows the parallel supply structures of the conductive current expansion structure 3 on a first electrode 2. The parallel supply structures of the conductive current expansion structure 3 can be covered with an inorganic passivation layer 4 (not shown here).

[0088] The Fig. Figures 3 to 8 each show only one conductive current expansion structure 3. However, what is described here also applies analogously to more than one conductive current expansion structure 3. Fig. 2 to 8 may further comprise one or more hole transport layers and / or hole injection layers, in particular between the organic functional layer stack 5 and the anode, and / or one or more electron transport layers and / or electron injection layers, in particular between the organic functional layer stack 5 and the cathode (not shown here).

[0089] Fig. Figure 3A shows a schematic section of an organic light-emitting component 100 according to a comparative example. Fig. Figure 3B shows a schematic section of an organic light-emitting component 100 according to one embodiment. Fig. Figure 3A shows a substrate 1 and, downstream, a first electrode 2, a conductive current-expansion structure 3, and an inorganic passivation layer 4. The substrate 1 can, for example, be made of glass. The first electrode 2 is preferably configured as an anode and is transparent or semi-transparent. A conductive current-expansion structure 3, which comprises or consists of a metal, is arranged in direct mechanical contact with the first electrode 2. The conductive current-expansion structure 3 is covered on all sides, that is, on all sides, particularly on three sides, by an inorganic passivation layer 4. The inorganic passivation layer 4 consists of, or preferably comprises, the sulfide of the metal of the conductive current-expansion structure 3. If, for example, the conductive current-expansion structure 3 is formed of silver, the inorganic passivation layer 4 comprises silver sulfide as its material.

[0090] Fig. 3B differs from the Fig. 3A by virtue of the conductive current expansion structure 3 having a layer structure 301, 302, 303. The layers of the conductive current expansion structure contain different metals. Adjacent layers contain different metals. The lower layer 301 consists of silver, layer 302 of another arbitrary metal, and layer 303 of silver. The inorganic passivation layer 4 thus also has a different composition, in particular a layer structure 401, 402, 403. The inorganic passivation layer 4 contains silver sulfide where layer 303 is located, a sulfide of the metal where layer 302 is located, and silver sulfide where layer 301 is located. This allows an inorganic passivation layer 4 to be created, which has a mixture of different sulfides 401, 402, 403 of the metals of the conductive current expansion structure 3.

[0091] The Fig. 4A and Fig. Figures 4B each show a schematic side view of a section of an organic light-emitting component 100 according to a comparative example. Fig. Figure 4A shows a first electrode 2 over which a conductive current expansion structure 3 is arranged. The conductive current expansion structure 3 has a layer sequence 301, 302, 303. Fig. Figure 4B shows the sulfidation of the conductive current-expansion structure and thus the formation of the inorganic passivation layer 4, at least on the surface 3-1 and on the side faces 3-2 of the conductive current-expansion structure 3. The formation of an inorganic passivation layer 4 prevents a direct current flow from the conductive current-expansion structure 3 into the organic functional layer stack 5, so that the current J flows through the first electrode 2 into the organic functional layer stack 5. This is particularly the case when the first electrode 2 is configured as an anode and the inorganic passivation layer 4 is an n-type semiconductor, or when the first electrode is configured as a cathode and the inorganic passivation layer 4 is a p-type semiconductor.The inorganic passivation layer 4 thus insulates the conductive current-expansion structure 3 and at least one organic functional layer stack 5, thereby preventing hole transport of holes injected from the anode or electron transport of electrons injected from the cathode. The device 100 can have a further layer 10, which is, for example, a hole injection layer and / or hole transport layer. Instead of a layered structure of the conductive current-expansion structure 3, it can also be a single layer of a metal, preferably silver.

[0092] The Fig. Figure 5 shows a method for producing an organic light-emitting component 100 according to a comparative example. Fig. Figure 5A shows the provision of substrate 1. On substrate 1, in the Fig. 5B a first electrode 2 is applied. In particular, the first electrode 2 is applied directly to the substrate 1. Fig. Figure 5C shows the application of at least one conductive current expansion structure 3 to the first electrode 2. The conductive current expansion structure 3 has a surface 3-1 facing away from the substrate and side surfaces 3-2. The conductive current expansion structure 3 can be generated by applying the material of the conductive current expansion structure 3 to the entire surface of the substrate 1 or the first electrode 2. Alternatively or additionally, the conductive current expansion structure 3 can also be applied selectively to the first electrode 2. Subsequently, the device can be assembled in the Fig. 5C treatment (represented by arrow 9). Treatment 9 can be carried out with a hydrogen sulfide atmosphere, a sulfur-containing or sulfur-ion-containing solution, or a sulfur-containing or sulfur-ion-containing plasma. This results, as in Fig. As shown in 5D, an inorganic passivation layer 4 is formed. The inorganic passivation layer 4 contains, in particular, sulfides of the metal or alloy of the conductive current-expansion structure 3. Thus, no additional material is applied to the conductive current-expansion structure 3; rather, the inorganic passivation layer 4 is generated in situ from the conductive current-expansion structure 3. Fig. 5E then deposits an organic functional layer stack 5 at least onto the inorganic passivation layer 4 and at least partially onto the first electrode 2. Subsequently, in the Fig. 5F the application of a second electrode 6.

[0093] The Fig. Figure 6 shows a schematic procedure for the production of an organic light-emitting component 100 according to a comparative example. Fig. Figure 6A shows the preparation of a substrate 1 and a first electrode 2. A material for a conductive current expansion structure 3 is applied to this first electrode 2 over its entire surface in an unstructured manner. Subsequently, the conductive current expansion structure 3 is generated, for example, by etching processes. This results in at least one conductive current expansion structure 3 ( Fig. 6B). In the Fig. 6C The conductive current expansion structure 3 is then treated with a hydrogen sulfide atmosphere, a sulfur-ion-containing solution, and / or a sulfur-ion-containing plasma, resulting in the formation of an inorganic passivation layer 4. The inorganic passivation layer 4 forms selectively on the conductive current expansion structures 3 and acts as an insulator, at least for holes or electrons. The inorganic passivation layer 4 is formed, in particular, from the sulfide of the metal of the conductive current expansion structure 3. Fig. Figure 6D shows the application of the organic functional layer stack 5. Instead of a layered structure of the conductive current expansion structure 3, it can also be a single layer of a metal, preferably silver.

[0094] Fig. Figure 7 shows a schematic procedure for the fabrication of an organic light-emitting component 100 according to a comparative example. Fig. Figure 7A shows a substrate 1, a second electrode 2, and a material applied over the entire surface of the second electrode 2 for the conductive current expansion structure 3. The material is then structured to form a conductive current expansion structure 3 (not shown here). A protective layer 11, which is in particular an oxide, selenide, telluride, or sulfide protective layer, is then selectively applied, i.e., to the free areas of the first electrode 2 that are not covered by the conductive current expansion structure 3. This protects the first electrode 2 from sulfidation. Subsequently, in the Fig. 7C the treatment 9, for example, using hydrogen sulfide, whereby the conductive current expansion structure 3 then forms an inorganic passivation layer 4. Due to the protective layer 11, the first electrode 2, for example made of TCO, is protected from this sulfidation. Subsequently, the protective layer 11 can be removed (not shown here) and the inorganic functional layer stack 5 can be applied ( Fig. 7D). Instead of a layered structure of the conductive current expansion structure 3, it can also be a single layer made of a metal, preferably silver.

[0095] The Fig. Figure 8 schematically shows a process for the production of an organic light-emitting component 100 according to a comparative example. Fig. 8A and Fig. 8B correspond to the Fig. 6A and Fig. 6B. In the Fig. In step 8C, a metal layer 12 is now applied at least to the surface 3-1 and to the side surfaces 3-2 of the conductive current expansion structure 3. Fig. In step 8D, this metal layer 12 is, for example, sulfidized or telluridized, so that an inorganic passivation layer 4 is formed from the metal layer 12 by treatment, for example with hydrogen sulfide or hydrogen telluride. Alternatively, the metal layer can also be only partially sulfidized or telluridized, so that the metal layer 12 is still present and directly adjacent to the inorganic passivation layer 4. Fig. 8E corresponds to the Fig. 6D. Instead of a layered structure of the conductive current expansion structure 3, it can also be a single layer made of a metal, preferably silver.

[0096] The in the Fig. 3 to 8 of the depicted components 100 may additionally have an encapsulation 7.

[0097] The invention simultaneously insulates the electrically conductive current expansion structure 3 from holes or electrons, thus preventing direct current flow through the passivation layer 4 and improving the low-resistance properties of the first electrode 2, which is made of ITO, for example. Furthermore, it creates a thinner structure to be covered for the encapsulation 7.

[0098] The advantage is that the inorganic passivation layer 4 is compatible with processes that influence electro-optical parameters, storage time and / or long-term stability.

[0099] In the proposed process, the etched and exposed metal structures (contacts, busbars) are treated to form an inorganic passivation layer 4 that is thick enough to prevent tunneling current. This eliminates the need for an additional resist. The contacts in the outer area can also be sulfidized or telluridized, but can then be exposed again by, for example, etching or ablation processes. In principle, all contacts can be treated in this way.

[0100] The embodiments and their features described in connection with the figures can also be combined with one another according to further embodiments, even if such combinations are not explicitly shown in the figures. Furthermore, the embodiments described in connection with the figures can have additional or alternative features as described in the general section.

Claims

[1] comprising an organic light-emitting component (100) - a substrate (1), - a first electrode (2) which is arranged above the substrate (1), - at least one organic functional layer stack (5) designed to emit radiation and arranged at least above the first electrode (2), - at least one conductive current expansion structure (3) arranged on the first electrode (2) and facing the organic functional layer stack (5), wherein the conductive current expansion structure (3) comprises at least one metal, wherein the conductive current expansion structure (3) has a layered structure (301, 302, 303) comprising two silver layers (301, 303), wherein the two silver layers (301, 303) are separated from each other by another metal layer (302) formed from a metal, wherein the conductive current expansion structure (3) is coated with an inorganic passivation layer (4), wherein the inorganic passivation layer (4) comprises a sulfide of at least one metal of the conductive current-expansion structure (3), wherein the inorganic passivation layer (4) has a layer structure (401, 402, 403) which, where the silver layers (301, 303) are arranged, has silver sulfide, and where the metal layer (302) is arranged, has a sulfide of the metal, wherein the inorganic passivation layer (4) is either an n- or a p-type semiconductor, such that no current flow occurs between the conductive current expansion structure (3) and the organic functional layer stack (5) via the inorganic passivation layer (4), and - a second electrode (6) arranged above the organic functional layer stack (5). [2] Organic light-emitting device (100) according to claim 1, wherein the inorganic passivation layer (4) is produced by sulfidation of the at least one metal of the conductive current expansion structure (3). [3] Organic light-emitting device (100) according to one of the preceding claims, wherein the first electrode (2) is configured as an anode and the inorganic passivation layer (4) is an n-type semiconductor, such that hole transport from the first electrode (2) via the inorganic passivation layer (4) towards the organic functional layer stack (5) is prevented. [4] Organic light-emitting device (100) according to one of the preceding claims, wherein the conductive current expansion structure (3) comprises silver as a metal and the inorganic passivation layer (4) comprises silver sulfide. [5] Organic light-emitting device (100) according to any of the preceding claims, which emits the radiation generated by the organic functional layer stack (5) via the first electrode (2) and the substrate (1). [6] Organic light-emitting device (100) according to one of claims 1, 2, 4 or 5 wherein the first electrode (2) or the second electrode (6) is configured as a cathode and the inorganic passivation layer (4) is a p-type semiconductor, such that electron transport from the first electrode (2) or the second electrode (6) via the inorganic passivation layer (4) towards the organic functional layer stack (5) is prevented. [7] Organic light-emitting device (100) according to the preceding claim, wherein the second electrode (6) is configured as a cathode and emits the radiation generated by the organic functional layer stack (5) via both the first electrode (2) and the second electrode (6). [8] Organic light-emitting device (100) according to one of the preceding claims, wherein the inorganic passivation layer (4) is a mixture of at least two different metal sulfides. [9] Organic light-emitting device (100) according to one of the preceding claims, wherein the inorganic passivation layer (4) has a layer thickness between 10 nm and 100 nm inclusive. [10] Organic light-emitting device (100) according to one of the preceding claims, wherein the conductive current expansion structure (3) has a surface (3-1) facing away from the substrate (1) and side surfaces (3-2), wherein the inorganic passivation layer (4) directly covers both the surface (3-1) and the side surfaces (3-2). [11] Method for producing an organic light-emitting device according to any one of claims 1 to 10, comprising the steps: A) Providing a substrate (1), B) Applying a first electrode (2) to the substrate (1), C) Deposition of at least one conductive current expansion structure (3) onto the first electrode (2), wherein the conductive current expansion structure (3) comprises at least one metal and a surface (3-1) and side faces (3-2) facing away from the substrate (1), wherein the conductive current expansion structure (3) has a layered structure (301, 302, 303) comprising two silver layers (301, 303), the two silver layers (301, 303) being separated from each other by a further metal layer (302) formed from a metal, D) Selective formation of an inorganic passivation layer (4) at least on the surface (3-1) and the side faces (3-2) of the conductive current expansion structure (3), wherein the inorganic passivation layer (4) comprises a sulfide of the at least one metal of the conductive current expansion structure (3), wherein the inorganic passivation layer (4) is either an n- or a p-type semiconductor is,so that no current flow occurs between the conductive current expansion structure (3) and the organic functional layer stack (5) via the inorganic passivation layer (4), wherein the inorganic passivation layer (4) has a layer structure (401, 402, 403) which, where the silver layers (301, 303) are arranged, has silver sulfide, and where the metal layer (302) is arranged, has a sulfide of the metal, E) Application of an organic functional layer stack (5) at least onto the inorganic passivation layer (4) and at least partially onto the first electrode (2), and F) Applying a second electrode (6). [12] Method according to claim 11, wherein an additional step C1) is performed before step D): C1) Selective application of a protective layer (11) to areas of the first electrode (2) that are free from the conductive current expansion structure (3), wherein after step D) an additional step D1) is performed: D1) Removal of the protective layer (11). [13] Method according to one of claims 11 to 12, wherein step D) is carried out using an atmosphere containing hydrogen sulfide, a sulfur-containing solution or a sulfur-containing plasma.

Images