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

Abstract

Organic light-emitting component (100) with an organic functional layer stack (9) between two electrodes (2, 8), - wherein the organic functional layer stack (9) comprises at least two organic light-emitting layers (4, 6) and at least one charge carrier generation layer (5) arranged between the two organic light-emitting layers (4, 6), - wherein the charge carrier generation layer (5) comprises an electron-conducting and hole-conducting organic layer (51, 53), between which an intermediate layer (52) is arranged, - wherein the intermediate layer (52) comprises a connecting material (11) aligned in the intermediate layer (52), - wherein molecules of the connecting material (11) each have at least one transition dipole moment (13) for the light emitted by the component, wherein: <cos 2θ> greater than 1 / 3, so that absorption of the light emitted by the component in the intermediate layer (52) is reduced, where θ is the angle between the respective transition dipole moment (13) of the molecules of the connecting material (11) and a layer normal (N).

Description

[0001] An organic light-emitting component is specified. Furthermore, a method for producing an organic light-emitting component is specified.

[0002] The following publications concern organic light-emitting devices: DE 10 2012 203 583 A1, DE 11 2012 001 504 T5, DE 10 2013 013 129 A1.

[0003] One problem to be solved is to provide an organic light-emitting component that reduces absorption losses and thus increases the efficiency of the component.

[0004] The organic light-emitting component comprises an organic functional layer stack. The organic functional layer stack is arranged between two electrodes. The organic functional layer stack comprises at least two organic light-emitting layers and at least one charge carrier generation layer. The charge carrier generation layer is arranged between the two organic light-emitting layers. The charge carrier generation layer comprises a hole-conducting and electron-conducting organic layer, in particular a p- and an n-doped organic layer. An intermediate layer is arranged between the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer. The intermediate layer comprises a connecting material or consists of this connecting material. The connecting material is oriented or aligned in the intermediate layer.The connecting material comprises molecules. The molecules each exhibit at least one transition dipole moment for the light emitted by the component. In particular, the following applies: <cos. 2 θ> greater than 1 / 3, so that absorption of the light emitted by the device in the intermediate layer is reduced, where θ is the angle between the respective transition dipole moment of the molecules of the connecting material and a layer normal N. In particular, the transition dipole moments are arranged parallel to the layer normal N with a maximum deviation of + / - 89° or + / - 45° from this parallel orientation.

[0005] The orientation factor K can be used as a measure for the orientation of molecules θ = <cos 2θ> can be used. For the term orientation factor, particular reference is made to: IUPAC. Compendium of Chemical Terminology, PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, third edition (IUPAC Recommendations 2006), page 371, DOI: 10.1351 / goldbook.MT07422. The disclosure content of this document is incorporated by reference.

[0006] The transition dipole moments of the molecules of the compound material preferably have an anisotropic orientation in total, meaning in particular that the orientation factor K θ is not equal to 1 / 3. In particular, <cos 2 θ>greater than 1 / 3, the transition dipole moment is preferably aligned along the layer normal N. The angle θ is the angle between the respective transition dipole moment of the molecules of the bonding material and the layer normal N, where the layer normal N is perpendicular to the intermediate layer. The orientation factor K θis averaged over all molecules. In particular, <cos 2 θ> greater than 0.4; 0.5; 0.6; 0.7; 0.8; 0.9 or 0.95 or equal to 1. The larger K θ The higher the density, the lower the absorption probability. This provides an organic light-emitting component with an intermediate layer that reduces the absorption of the light emitted by the component by aligning the molecules of the compound material. The efficiency of the component is increased while maintaining the high stability of the intermediate layer. The morphology of the organic layers, especially the intermediate layer, further contributes to increasing the efficiency and stability of the component.

[0007] According to at least one embodiment, the organic light-emitting component is an organic light-emitting diode (OLED). The organic light-emitting component has at least two organic light-emitting layers. These organic light-emitting layers can be stacked vertically. Thus, higher efficiency can be achieved by using multiple vertically stacked organic light-emitting layers. The stacked organic light-emitting layers are spatially separated by a charge generation layer (CGL). This can make it possible to generate multiple photons per charge carrier pair injected into such a stack, since the charge generation layers act like internal anodes and cathodes.

[0008] According to at least one embodiment, the organic light-emitting component comprises an organic functional layer stack.

[0009] The organic functional layer stack can comprise layers with organic polymers, organic oligomers, organic monomers, organic small, non-polymeric molecules (“small molecules”), or combinations thereof. In addition to the at least two organic light-emitting layers, the organic functional layer stack can comprise at least one functional layer designed as a hole-transport layer to enable effective hole injection into at least one of the light-emitting layers. Materials that can prove advantageous for a hole-transport layer include, for example, tertiary amines, carbazole derivatives, polyaniline doped with camphorsulfonic acid, or polyethylenedioxythiophene doped with polystyrenesulfonic acid. The organic functional layer stack can further comprise at least one functional layer designed as an electron-transport layer.In general, the organic functional layer stack may comprise, in addition to the at least two organic light-emitting layers, a plurality of organic functional layers selected from hole injection layers, hole transport layers, electron injection layers, electron transport layers, hole blocking layers and electron blocking layers.

[0010] According to at least one embodiment, an organic light-emitting component has at least two electrodes between which an organic functional layer stack is arranged.

[0011] According to at least one embodiment, at least one of the electrodes is transparent. Here and below, "transparent" refers to a layer that is transparent 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. Particularly preferably, a layer referred to as transparent here is as light-transmissive as possible, so that, in particular, the absorption of light generated in the organic functional layer stack during operation of the component is as low as possible.

[0012] According to at least one embodiment, both electrodes are transparent. This allows the light generated in the at least two light-emitting layers to be emitted in both directions, i.e., through both electrodes. If the organic light-emitting 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 organic light-emitting component can be transparent, so that the organic light-emitting component forms a transparent OLED.Furthermore, it may also be possible for one of the two electrodes between which the organic functional layer stack is arranged to be non-transparent and preferably reflective, so that the light generated in the at least two light-emitting layers between the two electrodes 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. If the electrode arranged away from the substrate is transparent, this is referred to as a top emitter.

[0013] A transparent conductive oxide, for example, can be used as a material for a transparent electrode. Transparent conductive oxides (TCO) are transparent, conductive materials, usually 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 In4Sn3O are also included. 12 or mixtures of different transparent conducting oxides belong to the group of TCOs. Furthermore, TCOs do not necessarily have a stoichiometric composition and can also be p- or n-doped.

[0014] According to at least one embodiment, the organic light-emitting component comprises a substrate. In particular, one of the two electrodes 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, or silicon wafer. In particular, the substrate comprises or consists of glass.

[0015] According to at least one embodiment, the organic light-emitting component has a charge carrier generation layer. The charge carrier generation layer is arranged between the two organic light-emitting layers. A charge carrier generation layer is used here and below to describe a layer sequence that is generally formed by a pn junction. The charge carrier generation layer, which can also be referred to as a so-called "charge generation layer" (CGL), is designed in particular as a pn junction forming a tunnel junction, which is operated in the reverse direction and can be used for effective charge separation and thus for the generation of charge carriers. The charge carrier generation layer connects at least the two organic light-emitting layers to one another. This can increase the stability of the component.

[0016] The charge generation layer can be formed from insulating materials, such as aluminum oxide. In this case, the charge generation layer acts as a tunnel barrier for the charge carriers. At the same time, the charge generation layer separates the hole-conducting and electron-conducting organic layers, especially the p- and n-doped organic layers, which would otherwise potentially react with each other at the interface and thus lose their function in the device. This increases the stability of the device.

[0017] Additionally, other materials, such as phthalocyanines, can be included in the charge-carrier-generation layer. Phthalocyanines exhibit intermediate states that increase the tunneling probability. The charge carriers can move from intermediate state to intermediate state between the hole-conducting and electron-conducting organic layers, particularly the p- and n-doped organic layers, through the so-called hopping mechanism of the phthalocyanines. This enables charge transport not only by tunneling but also by hopping. This can increase the efficiency of the device.

[0018] According to at least one embodiment, the charge carrier generation layer comprises a hole-conducting and electron-conducting organic layer, in particular a p- and n-doped organic layer. Here and below, p- and / or n-doped organic layer means that the organic layer is doped with a further charge carrier type that is different from the organic layer. P-doped here means that the organic layer is electron-conducting. N-doped here means that the organic layer is hole-conducting. Suitable materials for a hole-conducting and electron-conducting organic layer, in particular a p- and / or n-doped organic layer, include any materials that are electron-conducting and / or hole-conducting.

[0019] According to at least one embodiment, the charge carrier generation layer comprises an intermediate layer between the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer. In particular, the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer, are connected to one another via this intermediate layer. This means that the intermediate layer is arranged in direct contact with the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer.

[0020] According to at least one embodiment, the intermediate layer comprises a connecting material. In particular, the intermediate layer is formed from the connecting material, i.e., consists of the connecting material. The connecting material is oriented or aligned in the intermediate layer. By oriented or aligned here and below, we mean that the connecting material and / or the molecules of the connecting material and / or the transition dipole moment of the molecules adopt a preferred direction in the intermediate layer. The connecting material comprises molecules. The molecules have a transition dipole moment, in particular a plurality of transition dipole moments. The molecules have at least one transition dipole moment for the light emitted and / or generated by the component. In particular, the transition dipole moments are arranged parallel to the layer normal.The transition dipole moments of the molecules can alternatively or additionally be arranged with a deviation of up to + / - 89°, for example + / - 85°, 80°, 70°, 60°, 50°, 40°, 35°, 30°, 25°, 20°, 15°, 10° or 5° from this parallel orientation. In particular, on average, all transition dipole moments of the molecules exhibit a parallel arrangement + / - 45° to the layer normal. Layer normal here and in the following refers to a preferred direction that is arranged perpendicular to the intermediate layer. In particular, <cos. 2 θ> greater than 0.4; 0.5; 0.6; 0.7; 0.8; 0.9 or 0.95 or equal to 1.

[0021] The transition dipole moment has a fixed direction in the coordinate system of the bonding material (molecular coordinate system). This means, in particular, that by aligning the bonding material in the interlayer, i.e., in space, its transition dipole moment is also aligned.

[0022] For the term transition dipole moment, reference is made in particular to: "IUPAC. Compendium of Chemical Terminology, Second Edition (The "Gold Book"), 1997 or IUPAC. Compendium of Chemical Terminology, PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, third edition (IUPAC Recommendations 2006)) on page 434, DOI: 10.1351 / goldbook.T06460. The disclosure content of the documents is incorporated by reference.

[0023] According to at least one embodiment, all molecules of the connecting material have a transition dipole moment which is arranged in a parallel orientation to the layer normal with a maximum deviation of + / - 45° from this parallel orientation, for example 30°.

[0024] According to at least one embodiment, at least 50% or 60% or 70% or 80% or 90% or 95% of all molecules of the connecting material have a transition dipole moment that is arranged parallel to the layer normal N with a maximum deviation of + / - 45° from this parallel orientation. In particular, <cos 2 θ> greater than 0.4; 0.5; 0.6; 0.7; 0.8; 0.9 or 0.95 or equal to 1.

[0025] The transition dipole moments exhibit a specific orientation in the interlayer. This is relevant because the absorption and / or emission process is a dipole transition. By arranging the transition dipole moments of the molecules in a parallel arrangement with a maximum deviation of + / - 85° or 45° from the layer normal, the absorption of the light emitted by the device in the interlayer can be reduced compared to a device with transition dipole moments perpendicular to the layer normal.

[0026] The intermediate layer of the component according to the invention absorbs less light generated by the component. This allows more light to be emitted from the component, thus increasing the efficiency of light extraction from the organic light-emitting component.

[0027] Isotropically oriented interconnect material can absorb the light generated by the device due to intermediate states. The orientation of the interconnect material in the intermediate layer can reduce absorption.

[0028] According to at least one embodiment, the charge carrier generation layer additionally comprises a metal layer. The metal layer has a surface. In particular, the metal layer is arranged with a side facing away from the surface directly on the hole-conducting and / or electron-conducting organic layer, in particular the p- and / or n-doped organic layer of the charge carrier generation layer. The surface of the metal layer can be adjacent to the intermediate layer. In particular, the metal layer is arranged directly on the intermediate layer. The intermediate layer, which comprises the bonding material, is in particular covalently bonded to the surface of the metal layer. The bonding material forms a self-assembling monolayer (SAM).The transition dipole moments of the molecules of the bonding material are arranged parallel to the layer normal N with a maximum deviation of + / - 50°, 45°, 30°, 20°, 15°, or 10° from this parallel orientation. Aligning the molecules of the bonding material can reduce absorption losses.

[0029] According to at least one embodiment, the metal layer comprises or consists of a metal selected from a group comprising copper, silver, gold, and aluminum. In particular, the metal layer is a thin layer, for example, with a thickness of greater than or equal to 0.1 nm and less than or equal to 5 nm. In particular, the metal layer has a layer thickness of less than 1 nm, for example, 0.4 or 0.8 nm.

[0030] According to at least one embodiment, the metal layer is selected from a metal comprising copper, silver, or gold, wherein the metal layer has a layer thickness of less than 1 nm, and wherein the bonding material comprises sulfur, and wherein the sulfur is covalently bonded to the surface of the metal layer via a metal-sulfur bond. In particular, the metal layer is arranged directly on the hole-conducting and / or electron-conducting organic layer, in particular a p- and / or n-doped organic layer. The bonding material in particular has a sulfur-containing functional group, for example a thiol group.

[0031] In particular, the metal layer is formed of gold, with a covalent gold-sulfur bond connecting the metal layer and the intermediate layer. This can improve the adhesion of the two layers to each other.

[0032] According to at least one embodiment, the connecting material of the intermediate layer is formed as a self-assembled monolayer, so-called self-assembly monolayers (SAMs). In addition to the covalent bonding of the connecting material to the metal layer, the SAMs also provide lateral stabilization of the layer through noncovalent interactions, such as the van der Wal interaction between neighboring molecules.

[0033] Common organic materials, such as phthalocyanines, can be used as the bonding material. These materials can be conjugated, i.e., aromatic, or unconjugated, i.e., non-aromatic. The molecular chain lengths of the materials can vary. By using a bonding material with different molecular chain lengths, an intermediate layer with an inhomogeneous layer thickness can be created.

[0034] The phthalocyanines can be substituted with thiol groups. Due to the molecular structure of the phthalocyanines and the hybridization of the phthalocyanines, the thiol groups are always oriented in the molecular plane of the compound material. The transition dipole moment for the light emitted by the component is also oriented in this molecular plane. In particular, the compound material can contain multiple thiol groups. The thiol groups act as anchor groups that covalently bond to the metal layer. A particularly strong covalent bond is formed when the metal layer is gold.

[0035] The bonding material can have a symmetric or asymmetric molecular structure. Asymmetric here and in the following means that the bonding material has a permanent electric dipole moment due to its molecular structure. Symmetric means that the molecule does not have a permanent electric dipole moment. An asymmetric bonding material can be created, for example, by attaching sulfur-containing groups to phthalocyanines on one side.

[0036] According to at least one embodiment, the connecting material is a substituted phthalocyanine, a substituted aromatic, octylphosphonic acid and / or a substituted heteroaromatic.

[0037] According to at least one embodiment, the compound material is a sulfur-substituted phthalocyanine, a sulfur-substituted aromatic and / or a sulfur-substituted heteroaromatic.

[0038] According to at least one embodiment, the bonding material is a sulfur-substituted copper phthalocyanine, a sulfur-substituted vanadyl phthalocyanine, or a sulfur-substituted titanyl phthalocyanine. In particular, these substituted phthalocyanines have a thiol group (SH group), which, after application to the organic light-emitting component, transforms into the metal-sulfur bond.

[0039] According to at least one embodiment, octylphosphonic acid is used as a bonding material. Octylphosphonic acid forms, in particular, self-assembling monolayers. Octylphosphonic acid can be deposited from the gas phase.

[0040] By using a metal layer and a monolayer-generating interconnect material in a charge-generating layer, absorption losses in the device can be reduced and efficiency increased. At the same time, these intermediate layers exhibit high stability due to their highly ordered structures as SAMs.

[0041] The metal layers can be used as seed layers. The metal layers can also be used as a source of charge carriers in the charge carrier generation layer, potentially eliminating the need for doping in the charge carrier generation layer.

[0042] According to at least one embodiment, the charge carrier generation layer has a layer thickness between 1 nm and 8 nm, in particular between 4 nm and 5 nm, for example 5 nm. The intermediate layer can have a layer thickness between 1 nm and 3 nm, for example 2 nm. In particular, the charge carrier generation layer has a layer thickness of less than 5 nm.

[0043] According to at least one embodiment, the bonding material is amphiphilic. The molecules of the bonding material each have a permanent dipole moment. The permanent dipole moments are predominantly arranged parallel to the layer normal N with a maximum deviation of + / - 45°, 30°, 20°, or 15° from this parallel orientation. In particular, the transition dipole moments are predominantly arranged parallel, in particular parallel, to the permanent dipole moment. Amphiphilic here and below refers to the bonding material having both a hydrophilic, i.e., water-loving, and a hydrophobic, i.e., water-repellent or lipophilic, region. This means that this substance is highly soluble in both polar and nonpolar solvents.Predominantly parallel means that more than 50%, 60%, 70%, 80%, 90% or 95% of the molecules have a parallel orientation with their permanent dipole moments to the layer normal and / or to the transition dipole moments. In particular, <cos. 2 θ> greater than 1 / 3; 0.4; 0.5; 0.6; 0.7; 0.8; 0.9 or 0.95 or equal to 1.

[0044] According to at least one embodiment, the connecting material is amphiphilic and the molecules of the connecting material each have a permanent dipole moment, wherein the permanent dipole moment is predominantly arranged parallel to the layer normal with a maximum deviation of + / - 30° or 45° from this parallel orientation.

[0045] Alternatively or additionally, the hole-conducting and / or electron-conducting organic layer, in particular p- and / or n-doped organic layer, can have a hydrophilic surface. Hydrophilic here means that the surface is polar. The connecting material has hydrophilic and hydrophobic regions. The hydrophilic region of the connecting material is oriented toward the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer, in particular p- and / or n-doped organic layer. The hydrophobic region of the connecting material faces away from the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer, in particular p- and / or n-doped organic layer. In other words, the use of amphiphilic connecting materials in intermediate layers creates an orientation of the intermediate layer.By aligning the permanent dipole moments predominantly parallel to the layer normal, absorption can be minimized and thus efficiency increased. In particular, the transition dipole moment and the permanent dipole moment of a molecule are arranged parallel to each other. Hydrophilic surfaces of the hole-conducting and / or electron-conducting organic layer, especially p- and / or n-doped organic layers, are hole or electron conductors.

[0046] Typical hydrophilic regions on molecules of the connecting material can be selected from a group including carboxylate groups, hydroxyls, amines, primary amino groups, amide groups, aldehyde groups, and sulfo groups. Hydrophilic surfaces of the hole-conducting and / or electron-conducting organic layer, in particular p- and / or n-doped organic layers, can also contain such groups.

[0047] According to at least one embodiment, the hole-conducting and / or electron-conducting organic layer, in particular a p- and / or n-doped organic layer, has a hydrophobic surface. The hydrophobic surface can, in particular, comprise aliphatically saturated radicals, methyl groups, or aromatic nuclei. The bonding material has a hydrophilic and hydrophobic region. The hydrophobic region of the bonding material is oriented toward the hydrophobic surface of the hole-conducting and / or electron-conducting organic layer, in particular a p- and / or n-doped layer. The hydrophilic region of the bonding material is oriented away from the hydrophobic surface of the hole-conducting and / or electron-conducting organic layer, in particular a p- or n-doped layer. In other words, the hydrophilic region of the bonding material faces away from the hydrophobic surface due to the different polarity.

[0048] By using amphiphilic bonding materials as interlayers, an orientation of the bonding material can be created within the interlayer. The amphiphilic molecules self-organize within the layer due to entropic effects and their molecular structure. This self-organization of the bonding material results in the transition dipole moment and / or the permanent dipole moments being arranged approximately parallel, with a maximum deviation of + / - 45° from this parallel alignment to the layer normal. This can reduce absorption losses, as this bonding material, due to its spatial orientation, absorbs little of the light emitted by the component.

[0049] Furthermore, a method for producing an organic light-emitting component is specified. In particular, the method produces the organic light-emitting component. The definitions and explanations described so far for the organic light-emitting component also apply to the method for producing an organic light-emitting component.

[0050] According to at least one embodiment, the method for producing an organic light-emitting component comprises the following method steps: A) Providing an electrode, B) Applying an organic light-emitting layer to the electrode, C) applying an organic layer to the organic light-emitting layer produced in step B), D) Applying an intermediate layer comprising a connecting material which self-organizes upon application, wherein molecules of the connecting material each have at least one transition dipole moment for the light emitted by the component, wherein: <cos 2 Θ> greater than 1 / 3, so that absorption of the light emitted by the component in the intermediate layer is reduced, where θ is the angle between the respective transition dipole moment of the molecules of the compound material and a layer normal N, E) Applying another organic layer to the intermediate layer, F) applying a further organic light-emitting layer to the further organic layer, and G) Applying a further electrode to the further organic light-emitting layer produced in step F).

[0051] In particular, the organic layer applied in step C) is a hole-conducting organic layer and the organic layer applied in step E) is an electron-conducting organic layer, or the organic layer applied in step C) is an electron-conducting organic layer and the organic layer applied in step E) is a hole-conducting organic layer.

[0052] The fact that a layer is arranged or applied on or above another layer can mean, here and below, that one layer is arranged in direct mechanical and / or electrical contact with the other layer. Furthermore, it can also mean that one layer is arranged indirectly above another layer. In this case, additional layers can be arranged between one and the other layer.

[0053] The fact that a layer is arranged between two other layers can mean, here and below, that one layer is arranged in direct mechanical and / or electrical contact or in indirect contact with one or two other layers. In the case of indirect contact, further layers can be arranged between the one layer and at least one of the other two layers.

[0054] According to at least one embodiment, an additional process step D1) is carried out before process step D): D1) Applying a metal layer of copper, silver or gold to the organic layer produced in step C) by means of vacuum evaporation, whereby a metal layer with a layer thickness of less than 5 nm, in particular less than 1 nm, is produced.

[0055] In the subsequent step D), the bonding material can be applied to the metal layer. The bonding material can comprise sulfur and then bonds covalently via a metal-sulfur bond to the metal layer, in particular to the surface of the metal layer, for example gold. The transition dipole moments of the bonding material molecules in this intermediate layer can, in particular, exhibit a parallel arrangement to the layer normal with a maximum deviation of + / - 30° from this parallel arrangement. In particular, <cos 2 θ> greater than 1 / 3 or greater than 0.8.

[0056] According to at least one embodiment, the intermediate layer is produced from the liquid phase in step D). Spin coating, screen printing, inkjet printing, gravure printing, or flexographic printing can be used. An oriented intermediate layer can be created during production without the need for additional process steps. This saves time and costs.

[0057] According to at least one embodiment, the intermediate layer is generated from the gas phase in step D). This can be done by vacuum evaporation. An oriented intermediate layer can be generated during production without the need for additional process steps. This saves time and costs.

[0058] The processes can be selected depending on the viscosity, solvent, surface energy and / or wetting properties of the bonding material.

[0059] Additional materials can also be mixed into the interlayer to adjust viscosity or surface energy. This can be achieved by adding additional solvents or fillers with polar and / or nonpolar groups and / or anionic surfactants. For example, fillers can be added that contain functional groups selected from: -COO (carboxylate), -SO3 (sulfonate), or -SO4 (sulfate).

[0060] According to at least one embodiment, the alignment of the connecting material in step D) takes place at low temperatures, for example, temperatures below 50°C. At such low temperatures, alignment cannot be achieved with external fields; therefore, according to the invention, the self-organization of the molecules of the connecting material is used.

[0061] The inventors have recognized that by using an oriented intermediate layer in the charge generation layer, an organic light-emitting component can be created that exhibits low absorption, thus increasing the component's efficiency. This can be achieved by orienting the intermediate layer with amphiphilic molecules and / or by self-assembling monolayers. The interconnect material then exhibits a self-assembling structure and thus a highly organized structure.

[0062] Furthermore, higher efficiency is ensured with consistently high device stability compared to state-of-the-art charge generation layers. Furthermore, the morphology can be influenced to improve device performance. The morphology can be influenced by the orientation of the interconnect material.

[0063] Furthermore, a component can be provided that potentially achieves increased stability through the uniform alignment of the molecules in the intermediate layer. The intermediate layer can be homogeneous.

[0064] Further advantages, advantageous embodiments and further developments emerge from the exemplary embodiments described below in conjunction with the figures.

[0065] They show: the Fig. 1 a schematic representation of an organic light-emitting component according to an embodiment, the Fig. 2A to 2C show a schematic representation of a section of an organic light-emitting component according to a further embodiment, the Fig. 3A and Fig. 3B shows a schematic representation of a section of an organic light-emitting component according to a further embodiment, and the Fig. 4A and Fig. 4B is a schematic representation of a section of an organic light-emitting component according to a further embodiment.

[0066] 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.

[0067] Fig. 1 shows a schematic representation of an organic light-emitting component 100 according to an embodiment, which comprises a substrate 1, for example made of glass. An organic functional layer stack 9 is arranged above the substrate 1 between two electrodes 2 and 8, for example made of gold and indium tin oxide. The organic functional layer stack 9 comprises at least two organic light-emitting layers 4 and 6. The organic light-emitting layers 4 and 6 can comprise Ir(ppy)3 as a material in a matrix material. At least one charge carrier generation layer 5 is arranged between the two organic light-emitting layers 4 and 6. The charge carrier generation layer 5 comprises a hole-conducting and electron-conducting organic layer, in particular a p- and an n-doped organic layer 51, 53. An intermediate layer 52 is arranged between these two layers.

[0068] For example, the lower electrode 2 can be configured as the anode and the upper electrode 8 as the cathode. Alternatively, the lower electrode 2 can be configured as the cathode and the upper electrode 8 as the anode. Depending on the polarity of the electrodes, the organic layer 51 can be p- or n-doped. For example, if the organic layer is n-doped, the organic layer 52 is p-doped, and vice versa.

[0069] Furthermore, it may also be possible for the organic functional layer stack 9 to have more than two organic light-emitting layers, in which case a charge carrier generation layer can be arranged between each two immediately adjacent organic light-emitting layers. The organic functional layer stack 9 can have further organic functional layers in addition to the described organic functional layers 4 and 6. In the exemplary embodiment shown, charge carrier injection and transport layers 3 and 7 are shown purely by way of example, which are hole- or electron-conducting depending on the polarity of the electrodes 2, 7.

[0070] Furthermore, an encapsulation arrangement, preferably in the form of a thin-film encapsulation (not shown), can be applied over the electrodes 2, 8 and the organic functional layer stack 9 in order to protect the organic light-emitting component 100 and in particular the layers of the organic functional layer stack 9 and the electrodes 2, 8 from damaging materials from the environment such as moisture and / or oxygen and / or other corrosive substances such as hydrogen sulfide.

[0071] The Fig. 2A to 2C each show a section of an organic light-emitting component 100 according to an embodiment. Fig. 2A to 2C each show an intermediate layer 52 comprising the bonding material 11. The bonding material 11 comprises molecules that each have at least one transition dipole moment 13 for the light emitted by the component. Fig. 2A and Fig. 2B show that the transition dipole moments are arranged parallel to the layer normal N. Fig. Figure 2C shows that the transition dipole moments 13 of the connecting material 11 exhibit a deviation of approximately 10° from the parallel arrangement to the layer normal. By aligning such connecting materials in an intermediate layer 52, absorption losses can be reduced.

[0072] The intermediate layer 52 of the Fig. 2A to 2C can be used in an organic light-emitting device 100, such as in Fig. 1 shown.

[0073] Fig. 3A and Fig. 3B show a section of an organic light-emitting component 100 according to an embodiment. Fig. 3A shows a hole-conducting and electron-conducting organic layer, in particular p- and n-doped organic layers 51, 53. A metal layer 13 is arranged directly on at least one organic layer 51, 53. The metal layer 13 is made of gold, in particular. Directly downstream of the metal layer 13 is an intermediate layer 52, which is arranged between this metal layer 13 and the organic layer 51. In Fig. 3A, for example, the organic layer 51 may be n-doped and the organic layer 53 may be p-doped. Alternatively, the metal layer 13 may also be arranged on the organic layer 51, as shown in Fig. 3B. Here, for example, the organic layer 51 can be n-doped and the organic layer 53 can be p-doped, or vice versa.

[0074] The Fig. 4A and Fig. 4B show a section of an organic light-emitting component 100 according to one embodiment. An intermediate layer 52 can be arranged between the hole-conducting and electron-conducting organic layers, in particular n- and p-doped layers 51, 53. The intermediate layer 52 comprises a connecting material 11 that is amphiphilic. Amphiphilic here means that the connecting material has a hydrophilic region 11a and a hydrophobic region 11b. The organic layer 53, which can be p- or n-doped, has a hydrophilic surface. The surface of the other organic layer 51 can be hydrophobic. Because the surfaces of the hole-conducting and / or electron-conducting organic layers, in particular p- and / or n-doped organic layers 51, 53, are different, the amphiphilic connecting material 11 is oriented differently in space depending on the polarity.This means that the hydrophilic region 11a is oriented toward the hydrophilic surface of the hole-conducting or electron-conducting organic layer, in particular p- or n-doped organic layer 53, and that the hydrophobic region 11b of the connecting material 11 is oriented toward the hydrophobic surface of the other hole-conducting or electron-conducting organic layer, in particular p- or n-doped organic layer 51. This can create an orientation of the connecting material 11 in the intermediate layer 52. In this case, the organic layer 51 can be p-doped and the organic layer 53 can be n-doped, or vice versa.

[0075] The Fig. 4B shows the reverse case to Fig. 4A. The Fig. Figure 4B shows that the organic layer 51 has a hydrophilic surface and the organic layer 53 has a hydrophobic surface. This allows an orientation opposite to that of Fig. 4A can be generated.

[0076] 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 shown in 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] Organic light-emitting component (100) with an organic functional layer stack (9) between two electrodes (2, 8), - wherein the organic functional layer stack (9) comprises at least two organic light-emitting layers (4, 6) and at least one charge carrier generation layer (5) arranged between the two organic light-emitting layers (4, 6), - wherein the charge carrier generation layer (5) comprises an electron-conducting and hole-conducting organic layer (51, 53), between which an intermediate layer (52) is arranged, - wherein the intermediate layer (52) comprises a connecting material (11) aligned in the intermediate layer (52), - wherein molecules of the connecting material (11) each have at least one transition dipole moment (13) for the light emitted by the component, wherein: <cos 2θ> greater than 1 / 3, so that absorption of the light emitted by the component in the intermediate layer (52) is reduced, where θ is the angle between the respective transition dipole moment (13) of the molecules of the connecting material (11) and a layer normal (N). [2] Organic light-emitting component (100) according to claim 1, - wherein the charge carrier generation layer (5) additionally comprises a metal layer (130) with a surface (14), - wherein the metal layer (130) is arranged with a side facing away from the surfaces (14) directly on the hole-conducting or electron-conducting organic layer (51, 53), wherein the connecting material (11) is covalently bonded to the surface (14) of the metal layer (130) and oriented as a self-organizing monolayer, wherein the transition dipole moments (13) are arranged parallel to the layer normal (N) with a maximum deviation of ± 45° from this parallel orientation. [3] Organic light-emitting component (100) according to the preceding claim, wherein the metal layer (130) comprises a metal selected from copper, silver or gold, wherein the metal layer (130) has a layer thickness of less than 1 nm, wherein the connecting material (11) comprises sulfur, wherein the sulfur is covalently bonded to the surface (14) of the metal layer (130) via a metal-sulfur bond. [4] Organic light-emitting component (100) according to one of the preceding claims, wherein the connecting material (11) comprises a substituted phthalocyanine, a substituted aromatic, octylphosphonic acid or a substituted heteroaromatic. [5] Organic light-emitting component (100) according to one of the preceding claims, wherein the connecting material (11) is a sulfur-substituted copper phthalocyanine, vanadyl phthalocyanine or titanyl phthalocyanine. [6] Organic light-emitting component (100) according to one of the preceding claims, wherein the charge carrier generation layer (5) has a layer thickness of less than 5 nm. [7] Organic light-emitting component (100) according to one of the preceding claims, wherein the connecting material (11) is amphiphilic and the molecules of the connecting material (11) each have a permanent dipole moment, wherein the permanent dipole moment is predominantly arranged parallel to the layer normal (N) with a maximum deviation of ± 45° from this parallel orientation, wherein the transition dipole moment (13) is oriented parallel to the permanent dipole moment. [8] Organic light-emitting component (100) according to one of the preceding claims, wherein the hole-conducting and / or electron-conducting organic layer (51, 53) has a hydrophilic surface, wherein the connecting material (11) has hydrophilic (11a) and hydrophobic (11b) regions, wherein the hydrophilic region (11a) of the connecting material (11) is oriented towards the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer (51, 53) and the hydrophobic region (11b) of the connecting material (11) is facing away from the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer (51, 53). [9] Organic light-emitting component (100) according to one of the preceding claims, wherein the hole-conducting and / or electron-conducting organic layer (51, 53) has a hydrophobic surface, wherein the connecting material (11) has a hydrophilic (11a) and hydrophobic region (11b), wherein the hydrophobic region (11b) of the connecting material (11) is oriented towards the hydrophobic surface of the hole-conducting and / or electron-conducting organic layer (51, 53) and the hydrophilic region (11a) faces away from the hydrophobic surface of the hole-conducting and / or electron-conducting organic layer (51, 53). [10] A method for producing an organic light-emitting component (100) according to claims 1 to 9, comprising the steps of: A) Providing an electrode (2), B) applying an organic light-emitting layer (4) to the electrode (2), C) applying an organic layer (51) to the organic light-emitting layer (4) produced in step B), D) applying an intermediate layer (52), wherein the intermediate layer (52) comprises a connecting material (11) which arranges itself in a self-organizing manner upon application, wherein molecules of the connecting material (11) each have at least one transition dipole moment (13) for the light emitted by the component, wherein: <cos 2 θ> greater than 1 / 3 , so that absorption of the light emitted by the component in the intermediate layer is reduced, where θ is the angle between the respective transition dipole moment of the molecules of the compound material and a layer normal (N), E) applying a further organic layer (53) to the intermediate layer (52), F) applying a further organic light-emitting layer (6) to the further organic layer (53), G) Applying a further electrode (7) to the further organic light-emitting layer (6) produced in step F). [11] Method according to claim 10, wherein an additional step D1) is carried out before step D): D1) Applying a metal layer (130) made of copper, silver or gold to the organic layer (51) produced in step C) by means of vacuum evaporation, whereby a metal layer (130) with a layer thickness of less than 1 nm is produced, whereby in the subsequent step D) the connecting material (11) is applied to the metal layer (130), which comprises sulfur and is covalently bonded to the metal layer (130) via a metal-sulfur bond, whereby the transition dipole moments (13) of the molecules of the connecting material (11) are arranged parallel to the layer normal (N) with a maximum deviation of ± 45° from this parallel orientation. [12] Method according to claim 10, wherein the intermediate layer (52) in step D) is applied from the liquid phase by means of spin coating, screen printing, inkjet, gravure printing or flexographic printing. [13] Method according to claim 10, wherein the intermediate layer (52) in step D) is applied from the gas phase by means of vacuum evaporation.

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