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

Abstract

Organic light-emitting device (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 generating layer (5) arranged between the two organic light-emitting layers (4, 6), - wherein the charge carrier generation layer (5) comprises an electron-conducting and a hole-conducting organic layer (51, 53) between which an intermediate layer (52) is arranged, - wherein the intermediate layer (52) comprises a connecting material (11) which is aligned in the intermediate layer (52), - wherein molecules of the compound material (11) each exhibit at least one transition dipole moment (13) for the light emitted by the component, and - wherein the compound material (11) is a sulfur-substituted phthalocyanine, a sulfur-substituted aromatic compound and / or a sulfur-substituted heteroaromatic compound.

Description

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

[0002] Document US 2007 / 0 181 887 A1 concerns a display device.

[0003] Claessens et al. discuss phthalocyanines and their properties in The Chemical Record, Vol. 8, 2008, No. 2, pp. 75-97.

[0004] Yokoyama discusses the molecular orientation in small-molecule organic light-emitting diodes in the Journal of Materials Chemistry, Vol. 21, 2011, No. 48, pp. 19187-19202.

[0005] Ruocco et al. discuss copper phthalocyanine ultrathin films grown on an Al(100) surface in the Journal of Electron Spectroscopy and Related Phenomena, Vol. 137-140, 2004, pp. 165-169.

[0006] One challenge to be solved is to specify an organic light-emitting component that reduces absorption losses and thus increases the efficiency of the component.

[0007] This problem is solved by the component according to claim 1.

[0008] The organic light-emitting device comprises an organic functional layer stack. The organic functional layer stack is arranged between two electrodes. The organic functional layer stack includes at least two organic light-emitting layers and at least one charge carrier generating layer. The charge carrier generating layer is arranged between the two organic light-emitting layers. The charge carrier generating layer comprises a hole-conducting and an electron-conducting organic layer, in particular a p- and an n-doped organic layer. An intermediate layer is arranged between the hole-conducting and the electron-conducting organic layer, in particular the p- and n-doped organic layer. The intermediate layer comprises or consists of a bonding material. The bonding material is oriented or aligned within the intermediate layer.The connecting material contains molecules. Each molecule exhibits at least one transition dipole moment for the light emitted by the component. In particular: <cos. 2 ϴ > greater than 1 / 3, so that absorption of the light emitted by the component in the interlayer is reduced, where ϴ is the angle between the respective transition dipole moments of the molecules of the interconnect 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 alignment.

[0009] The orientation factor K can be used as a measure of the orientation of molecules. ϴ = <cos 2ϴ> are used. For the term orientation factor, see in particular: IUPAC. Compendium of Chemical Terminology, PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, third edition (IUPAC Recommendations 2006), on page 371, DOI: 10.1351 / goldbook.MT07422.

[0010] The transition dipole moments of the molecules of the compound material preferably exhibit an anisotropic orientation in sum, meaning in particular that the orientation factor K ϴ is not equal to 1 / 3. In particular, is it <cos 2 If ϴ > greater than 1 / 3, the transition dipole moment is preferentially aligned along the layer normal N. The angle ϴ is the angle between the respective transition dipole moments of the molecules of the compound material and the layer normal N, where the layer normal N is perpendicular to the intermediate layer. The orientation factor K ϴ is averaged over all molecules. In particular, <cos 2ϴ > 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 concentration of the interlayer, the lower the absorption probability. This provides an organic light-emitting device with an interlayer that reduces the absorption of the light emitted by the device by aligning the molecules of the connecting material. The efficiency of the device is increased while maintaining the high stability of the interlayer. The morphology of the organic layers, especially the interlayer, further contributes to increasing the efficiency and stability of the device.

[0011] According to at least one embodiment, the organic light-emitting device is an organic light-emitting diode (OLED). The organic light-emitting device comprises at least two organic light-emitting layers. These organic light-emitting layers can be vertically stacked. 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 makes 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.

[0012] According to at least one embodiment, the organic light-emitting component has an organic functional layer stack.

[0013] The organic functional layer stack can comprise layers of organic polymers, organic oligomers, organic monomers, small organic non-polymeric molecules, or combinations thereof. In addition to the at least two organic light-emitting layers, the organic functional layer stack can include at least one functional layer configured as a hole transport layer to enable effective hole injection into at least one of the light-emitting layers. Suitable materials for a hole transport layer include, for example, tertiary amines, carbazole derivatives, camphorsulfonic acid-doped polyaniline, or polystyrenesulfonic acid-doped polyethylenedioxythiophene. The organic functional layer stack can further comprise at least one functional layer configured as an electron transport layer.In general, the organic functional layer stack can, in addition to the at least two organic light-emitting layers, include 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.

[0014] According to at least one embodiment, an organic light-emitting device has at least two electrodes between which an organically functional layer stack is arranged.

[0015] According to at least one embodiment, at least one of the electrodes is 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 device is as low as possible.

[0016] 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 device 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 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 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, it is referred to as a bottom emitter, while if the electrode facing away from the substrate is transparent, it is referred to as a top emitter.

[0017] A transparent conductive oxide can be used as a material for a transparent electrode. Transparent conductive oxides (TCOs) are transparent, 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.

[0018] According to at least one embodiment, the organic light-emitting device 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 wafers. In particular, the substrate comprises or consists of glass.

[0019] According to at least one embodiment, the organic light-emitting device has a charge carrier generation layer. The charge carrier generation layer is arranged between the two organic light-emitting layers. Here and in the following, a charge carrier generation layer is defined as a sequence of layers that is generally formed by a pn junction. The charge carrier generation layer, which can also be referred to as a "charge generation layer" (CGL), is specifically configured as a tunneling pn junction that operates in reverse 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. This increases the stability of the device.

[0020] The charge carrier generation layer can be made of insulating materials, such as aluminum oxide. In this case, the charge carrier generation layer acts as a tunnel barrier for the charge carriers. Simultaneously, the charge carrier generation layer separates the hole-conducting and electron-conducting organic layers, particularly the p- and n-doped organic layers, which might otherwise react with each other at the interface and thereby lose their function in the device. This increases the stability of the device.

[0021] Additionally, other materials, such as phthalocyanines, can be part of the charge carrier generation layer. Phthalocyanines exhibit intermediate states that increase the tunneling probability. The charge carriers can move between the hole-conducting and electron-conducting organic layers, particularly the p- and n-doped organic layers, via the so-called hopping mechanism from one intermediate state to another of the phthalocyanines. This allows charge transport not only through tunneling but also through hopping, thereby increasing the efficiency of the device.

[0022] 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 in the following, p- and / or n-doped organic layer means that the organic layer is doped with another type of charge carrier that differs from the organic layer itself. p-doped here means that the organic layer is electron-conducting. n-doped here means that the organic layer is hole-conducting. Any materials that are electron-conducting and / or hole-conducting are suitable as materials for a hole-conducting and electron-conducting organic layer, in particular a p- and / or n-doped organic layer.

[0023] According to at least one embodiment, the charge carrier generation layer has an intermediate layer between the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer. Specifically, the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer, are connected to each other via this intermediate layer. This means that the intermediate layer is in direct contact with the hole-conducting and electron-conducting organic layer, in particular the p- and n-doped organic layer.

[0024] According to at least one embodiment, the intermediate layer comprises a bonding material. In particular, the intermediate layer is formed from the bonding material, i.e., it consists entirely of the bonding material. The bonding material is oriented or aligned within the intermediate layer. "Oriented or aligned" here and in the following means that the bonding material and / or the molecules of the bonding material and / or the transition dipole moment of the molecules assume a preferred direction within the intermediate layer. The bonding material comprises molecules. The molecules possess a transition dipole moment, in particular several transition dipole moments. The molecules possess 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. Here and in the following, the layer normal denotes 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.

[0025] 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.

[0026] 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.

[0027] According to at least one embodiment, all molecules of the compound material have a transition dipole moment that is arranged in a parallel orientation to the layer normal with a maximum deviation of + / - 45° from this parallel orientation, for example 30°.

[0028] According to at least one embodiment, at least 50%, 60%, 70%, 80%, 90%, or 95% of all molecules of the compound 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.

[0029] The transition dipole moments in the interlayer exhibit a specific orientation. 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 configuration 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.

[0030] 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.

[0031] Isotropically oriented bonding material can absorb the light generated by the component due to intermediate states. Orienting the bonding material within the intermediate layer can reduce this absorption.

[0032] 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 one side facing away from the surface directly adjacent to the hole-conducting and / or electron-conducting organic layer, especially the p- and / or n-doped organic layer of the charge carrier generation layer. The surface of the metal layer can abut the intermediate layer. In particular, the metal layer is arranged directly adjacent to 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 aligned parallel to the layer normal N with a maximum deviation of + / - 50°, 45°, 30°, 20°, 15°, or 10° from this parallel alignment. This alignment of the bonding material molecules reduces absorption losses.

[0033] According to at least one embodiment, the metal layer comprises or consists of a metal selected from a group including copper, silver, gold, and aluminum. In particular, the metal layer is a thin layer, for example, with a thickness greater than or equal to 0.1 nm and less than or equal to 5 nm. In particular, the metal layer has a thickness of less than 1 nm, for example, 0.4 or 0.8 nm.

[0034] 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 thickness of less than 1 nm, and wherein the compound 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 directly attached to the hole-conducting and / or electron-conducting organic layer, especially a p- and / or n-doped organic layer. The compound material particularly comprises a sulfur-containing functional group, for example, a thiol group.

[0035] In particular, the metal layer is made of gold, with a covalent gold-sulfur bond connecting the metal layer and the intermediate layer. This improves the adhesion between the two layers.

[0036] According to at least one embodiment, the interlayer's bonding material is formed as a self-assembled monolayer, so-called self-assembly monolayers or SAMs. In addition to the covalent bonding of the bonding material to the metal layer, the SAMs also exhibit lateral stabilization of the layer through non-covalent interactions, such as van der Wals interactions between neighboring molecules.

[0037] Common organic materials, such as phthalocyanines, can be used as the bonding agent. These materials can be conjugated (aromatic) or unconjugated (non-aromatic). The molecular chain length of the material can vary. By using a bonding agent with different molecular chain lengths, an intermediate layer with a non-homogeneous thickness can be created.

[0038] Phthalocyanines can be substituted with thiol groups. Due to the molecular structure of phthalocyanines and their hybridization, the thiol groups are always oriented in the molecular plane of the compound material. The transition dipole moment for the light emitted by the device is also oriented in this molecular plane. In particular, the compound material can contain multiple thiol groups. Here, 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.

[0039] The compound can have a symmetrical or asymmetrical molecular structure. Asymmetrical, in this and the following, means that the compound has a permanent electric dipole moment due to its molecular structure. Symmetrical means that the molecule does not have a permanent electric dipole moment. An asymmetrical compound can be produced, for example, by attaching sulfur-containing groups to phthalocyanines on one side.

[0040] According to at least one embodiment, the compound material is a substituted phthalocyanine, a substituted aromatic compound, octylphosphonic acid and / or a substituted heteroaromatic compound.

[0041] The compound material is a sulfur-substituted phthalocyanine, a sulfur-substituted aromatic compound and / or a sulfur-substituted heteroaromatic compound.

[0042] According to at least one embodiment, the compound 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, upon application to the organic light-emitting device, transforms into the metal-sulfur bond.

[0043] According to at least one embodiment, octylphosphonic acid is used as a compound. Octylphosphonic acid particularly forms self-assembling monolayers. Octylphosphonic acid can be deposited from the gas phase.

[0044] By using a metal layer and a monolayer-forming interconnect material in a charge carrier generation 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.

[0045] The metal layers can be used as seed layers. Simultaneously, the metal layers can serve as a source of charge carriers in the charge carrier generation layer, potentially eliminating the need for doping in the charge carrier generation layer.

[0046] According to at least one embodiment, the charge carrier generation layer has a 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 thickness between 1 nm and 3 nm, for example 2 nm. In particular, the charge carrier generation layer has a thickness of less than 5 nm.

[0047] According to at least one embodiment, the compound material is amphiphilic. The molecules of the compound material each possess 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, especially parallel, to the permanent dipole moment. Here and in the following, amphiphilic means that the compound material has both a hydrophilic (water-loving) and a hydrophobic (water-repellent or lipophilic) region. This means that this substance is readily soluble in both polar and nonpolar solvents.Predominantly parallel here means that more than 50%, 60%, 70%, 80%, 90%, or 95% of the molecules, with their permanent dipole moments, exhibit an alignment parallel 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

[0048] According to at least one embodiment, the compound material is amphiphilic and the molecules of the compound 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 alignment. Alternatively or additionally, the hole-conducting and / or electron-conducting organic layer, in particular a p- and / or n-doped organic layer, can have a hydrophilic surface. Hydrophilic here means that the surface is polar. The compound material has hydrophilic and hydrophobic regions. The hydrophilic region of the compound material faces the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer, in particular a p- and / or n-doped organic layer. The hydrophobic region of the compound material faces away from the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer, in particular a p- and / or n-doped organic layer. In other words, the use of amphiphilic compound materials in interlayers creates an orientation of the interlayer.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. Specifically, hydrophilic surfaces of hole-conducting and / or electron-conducting organic layers, especially p- and / or n-doped organic layers, are hole or electron conductors.

[0049] Typical hydrophilic regions on molecules of the compound material can be selected from a group that includes 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, especially p- and / or n-doped organic layers, can also exhibit such groups.

[0050] 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 may, in particular, contain aliphatic saturated radicals, methyl groups, or aromatic rings. The compound material has a hydrophilic and a hydrophobic region. The hydrophobic region of the compound material is oriented towards 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 compound 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 compound material faces away from the hydrophobic surface due to the different polarity.

[0051] By using amphiphilic bonding materials as interlayers, an orientation of the bonding material within the interlayer can be created. 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 to each other, with a maximum deviation of ±45° from this parallel alignment to the layer normal. This reduces absorption losses, as the bonding material, due to its spatial orientation, absorbs very little of the light emitted by the component.

[0052] Furthermore, a method for manufacturing an organic light-emitting component is described. Specifically, the method manufactures the organic light-emitting component. The definitions and explanations previously described for the organic light-emitting component also apply to the method for manufacturing an organic light-emitting component.

[0053] According to at least one embodiment, the method for manufacturing an organic light-emitting component comprises the following process 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) Application of an intermediate layer comprising a bonding material which self-organizes upon application, wherein molecules of the bonding 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 bonding material and a layer normal N, E) Applying another organic layer to the intermediate layer, F) Applying another organic light-emitting layer onto the other organic layer, and G) Applying another electrode to the additional organic light-emitting layer produced in step F).

[0054] 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.

[0055] The fact that a layer is arranged or applied on or above another layer can mean, here and in the following, that one layer is in direct mechanical and / or electrical contact with the other layer. It can also mean that one layer is arranged indirectly above another layer. In this case, further layers may be arranged between the two layers.

[0056] The fact that a layer is arranged between two other layers can mean, here and in the following, that the one layer is 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 may be arranged between the one layer and at least one of the other two layers.

[0057] According to at least one embodiment, prior to process step D) an additional process step D1) D1) is applied to the organic layer produced under 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.

[0058] In the subsequent step D), the compound material can be applied to the metal layer. The compound material can include sulfur and then bonds covalently to the metal layer, particularly to the surface of the metal layer, for example, gold, via a metal-sulfur bond. The transition dipole moments of the molecules of the compound material can, in this intermediate layer, exhibit an arrangement parallel 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.

[0059] According to at least one embodiment, the intermediate layer is produced from the liquid phase in step D). Spin coating, screen printing, inkjet printing, engraved printing, or flexographic printing can be used as methods. An oriented intermediate layer can be created during production without the need for additional process steps. This saves time and costs.

[0060] According to at least one embodiment, the intermediate layer is produced from the gas phase in step D). This can be achieved by vacuum evaporation. An oriented intermediate layer can thus be produced during manufacturing without the need for additional process steps. This saves time and costs.

[0061] The processes can be selected depending on the viscosity, solvent, surface energy and / or wetting properties of the bonding material.

[0062] Additional materials can also be mixed into the interlayer to adjust the viscosity or surface energy. This is primarily achieved with additional solvents or further fillers with polar and / or nonpolar groups and / or anionic surfactants. For example, fillers can be added that have functional groups selected from: -COO (carboxylate), -SO3 (sulfonate), or -SO4 (sulfate).

[0063] According to at least one embodiment, the alignment of the bonding material in step D) takes place at low temperatures, for example, temperatures below 50 °C. At such low temperatures, alignment using external fields cannot be achieved; therefore, according to the invention, recourse is made to the self-organization of the molecules of the bonding material.

[0064] The inventors have recognized that by using an oriented interlayer in the charge generation layer, an organic light-emitting device can be provided that absorbs little light, thus increasing the device's efficiency. This can be achieved by orienting the interlayer with amphiphilic molecules and / or by using self-assembling monolayers. The resulting interconnect material then exhibits a self-assembling and therefore highly organized structure.

[0065] Furthermore, higher efficiency is ensured with consistently high component stability compared to state-of-the-art charge carrier generation layers. Additionally, the morphology can be influenced to improve component performance. This influence on the morphology can be achieved by orienting the interconnect material.

[0066] Furthermore, a component can be provided that generates potentially increased stability through the uniform alignment of the molecules in the interlayer. The interlayer can be homogeneous.

[0067] Further advantages, advantageous embodiments and further developments result from the exemplary embodiments described below in conjunction with the figures.

[0068] They show: the Fig. 1 a schematic representation of an organic light-emitting component according to an exemplary embodiment, the Fig. 2A to 2C are the schematic representation of a section of an organic light-emitting component according to a further embodiment. the Fig. 3A and Fig. 3B a schematic representation of a section of an organic light-emitting component according to a further embodiment, and the Fig. 4A and Fig. 4B a schematic representation of a section of an organic light-emitting component according to a further embodiment.

[0069] In the exemplary embodiments and figures, identical, similar, or similarly functioning 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.

[0070] Fig. Figure 1 shows a schematic representation of an organic light-emitting device 100 according to an embodiment, comprising 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 have Ir(ppy)3 as the material in a matrix material. At least one charge carrier generating layer 5 is arranged between the two organic light-emitting layers 4 and 6. The charge carrier generating layer 5 comprises a hole-conducting and an 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.

[0071] 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. If the organic layer is n-doped, for example, then the organic layer 52 is p-doped, and vice versa.

[0072] Furthermore, it is also possible that the organic functional layer stack 9 has more than two organic light-emitting layers, in which case a charge carrier generation layer can be arranged between each pair of immediately adjacent organic light-emitting layers. In addition to the organic functional layers 4 and 6 described above, the organic functional layer stack 9 can have further organic functional layers. In the illustrated embodiment, charge carrier injection and transport layers 3 and 7 are shown by way of example only; these layers are hole-conducting or electron-conducting depending on the polarity of the electrodes 2 and 7.

[0073] Furthermore, an encapsulation arrangement, preferably in the form of a thin-film encapsulation, can be applied over the electrodes 2, 8 and the organic functional layer stack 9 (not shown) to protect the organic light-emitting device 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.

[0074] The Fig. Figures 2A to 2C each show a section of an organic light-emitting component 100 according to one embodiment. Fig. Figures 2A to 2C each show an intermediate layer 52 containing the bonding material 11. The bonding material 11 has molecules that each exhibit at least one transition dipole moment 13 for the light emitted by the component. Fig. 2A and Fig. Figure 2B shows 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 bonding material 11 exhibit a deviation of approximately 10° from the parallel arrangement to the layer normal. By aligning such bonding materials in an intermediate layer 52, absorption losses can be reduced.

[0075] The intermediate layer 52 of the Fig. 2A to 2C can be in an organic light-emitting device 100, such as in Fig. 1 shown, to be included.

[0076] Fig. 3A and Fig. Figure 3B shows a section of an organic light-emitting component 100 according to one embodiment. Fig. Figure 3A shows a hole-conducting and electron-conducting organic layer, in particular a p- and n-doped organic layer 51, 53. A metal layer 13 is directly arranged on at least one organic layer 51, 53. The metal layer 13 is in particular made of gold. 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. Fig. For example, the organic layer 51 in 3A can be n-doped and the organic layer 53 p-doped. Alternatively, the metal layer 13 can also be arranged on the organic layer 51, as shown in the Fig. Figure 3B is shown. Here, for example, the organic layer 51 can be n-doped and the organic layer 53 p-doped, or vice versa.

[0077] The Fig. 4A and Fig. Figure 4B shows a section of an organic light-emitting device 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 compound material 11 that is amphiphilic. Amphiphilic here means that the compound 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 compound material 11 orients itself differently in space depending on its polarity.This means that the hydrophilic region 11a is oriented towards the hydrophilic surface of the hole-conducting or electron-conducting organic layer, in particular the p- or n-doped organic layer 53, and that the hydrophobic region 11b of the compound material 11 is oriented towards the hydrophobic surface of the other hole-conducting or electron-conducting organic layer, in particular the p- or n-doped organic layer 51. This allows the compound material 11 to be oriented within the intermediate layer 52. In this case, the organic layer 51 can be p-doped and the organic layer 53 n-doped, or vice versa.

[0078] The Fig. 4B shows the opposite 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 for an orientation opposite to that of the Fig. 4A will be generated.

[0079] 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] Organic light-emitting device (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 generating layer (5) arranged between the two organic light-emitting layers (4, 6), - wherein the charge carrier generation layer (5) comprises an electron-conducting and a hole-conducting organic layer (51, 53) between which an intermediate layer (52) is arranged, - wherein the intermediate layer (52) comprises a connecting material (11) which is aligned in the intermediate layer (52), - wherein molecules of the compound material (11) each exhibit at least one transition dipole moment (13) for the light emitted by the component, and - wherein the compound material (11) is a sulfur-substituted phthalocyanine, a sulfur-substituted aromatic compound and / or a sulfur-substituted heteroaromatic compound. [2] Organic light-emitting device (100) according to claim 1, wherein the intermediate layer (52) is in direct contact with the electron-conducting and hole-conducting organic layer (51, 53). [3] Organic light-emitting component (100) according to any one of the preceding claims, - wherein the charge carrier generation layer (5) additionally has a metal layer (130) with a surface (14), - wherein the metal layer (130) is arranged with one side facing away from the surfaces (14) directly on the hole-conducting or the electron-conducting organic layer (51, 53), wherein the connecting material (11) is covalently bonded to the surface (14) of the metal layer (130) and is 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. [4] Organic light-emitting device (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 sulfur of the compound material (11) is covalently bonded to the surface (14) of the metal layer (130) via a metal-sulfur bond. [5] Organic light-emitting device (100) according to any one of the preceding claims, wherein the compound material (11) is a sulfur-substituted copper phthalocyanine, vanadyl phthalocyanine or titanyl phthalocyanine. [6] Organic light-emitting device (100) according to one of the preceding claims, wherein the compound material (11) has a symmetrical molecular structure, wherein the molecules of the compound material (11) do not have a permanent electric dipole moment. [7] Organic light-emitting device (100) according to one of the preceding claims, wherein the compound material (11) has an asymmetric molecular structure, wherein the compound material (11) has a permanent electric dipole moment due to the asymmetric molecular structure. [8] Organic light-emitting device (100) according to one of the preceding claims, wherein the charge carrier generating layer (5) has a layer thickness of less than 5 nm. [9] Organic light-emitting device (100) according to one of the preceding claims, wherein the hole-conducting and / or the 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 turned away from the hydrophilic surface of the hole-conducting and / or electron-conducting organic layer (51, 53). [10] Organic light-emitting device (100) according to one of the preceding claims, wherein the hole-conducting and / or the 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) is turned away from the hydrophobic surface of the hole-conducting and / or electron-conducting organic layer (51, 53). [11] Method for producing an organic light-emitting component (100) according to claims 1 to 10 comprising the steps: 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) Application of an intermediate layer (52), wherein the intermediate layer (52) comprises a connecting material (11) which self-organizes 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 interlayer is reduced, where ϴ is the angle between the respective transition dipole moment of the molecules of the bonding material and a layer normal (N), E) Applying another organic layer (53) to the intermediate layer (52), F) Applying another organic light-emitting layer (6) to the other organic layer (53), G) Applying another electrode (7) to the further organic light-emitting layer (6) produced in step F). [12] Method according to claim 11, wherein an additional step D1) is performed before step D): D1) Deposition of a metal layer (130) of copper, silver or gold onto the organic layer (51) produced in step C) by vacuum evaporation, wherein a metal layer (130) with a layer thickness of less than 1 nm is produced, wherein in the subsequent step D) the compound material (11) comprising sulfur is applied to the metal layer (130) and is covalently bonded to the metal layer (130) via a metal-sulfur bond, wherein the transition dipole moments (13) of the molecules of the compound material (11) are arranged parallel to the layer normal (N) with a maximum deviation of ± 45° from this parallel orientation. [13] Method according to claim 11, wherein the intermediate layer (52) is applied from the liquid phase in step D) by means of spin coating, screen printing, inkjet printing, engraving printing or flexographic printing. [14] Method according to claim 11, wherein the intermediate layer (52) is applied from the gas phase by means of vacuum evaporation in step D).

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