WO2010031688A1

WO2010031688A1 - Optoelectronic organic component with improved light output and/or injection

Info

Publication number: WO2010031688A1
Application number: PCT/EP2009/061284
Authority: WO
Inventors: Anett Berndt; Florian Eder; Wiebke Sarfert; Heinrich Zeininger
Original assignee: Siemens Aktiengesellschaft
Priority date: 2008-09-19
Filing date: 2009-09-01
Publication date: 2010-03-25
Also published as: EP2329545A1; DE102008048161A1

Abstract

The invention relates to an organic optoelectronic component in which at least one lower electrode layer (12), then an optically active organic layer and, at the top, a counterelectrode, which need not necessarily be transparent, are arranged on a transparent substrate (16). The optoelectronic organic component has improved light output and/or injection and, in particular, has reduced total internal reflection at the interface between the transparent electrode and the substrate because scattering centres (15) are located in the transparent zone.

Description

description

Optoelectronic organic component with improved Lichtaus- and / or coupling

The invention relates to an organic optoelectronic component in which at least one lower electrode layer, then an optically active organic layer and at the top a counter electrode, which does not necessarily have to be transparent, are arranged on a transparent substrate. The optoelectronic organic component has improved Lichtaus- and / or -einkopplung, in particular it has a reduced total reflection at the interface between the transparent electrode and substrate.

Dispersing layers in optoelectronic organic components are known, wherein, for example, sandblasted substrates are used.

Using the example of the organic light-emitting diode (OLED), it is explained that, in the worst case scenario, up to 80% of the photons are lost - according to estimates from the classical radiation optics. The OLED usually comprises the following layers with different refractive indices: air (n = 1); Glass (substrate) (n = 1.5); lower electrode, z. B. ITO (n = 1.8 to 1.9); organic photoactive layer (n approx. 1.7). In the worst case, the total refraction occurs in the refraction of the light, but at least a multiple reflection and thus the radiation losses (trapped modes).

Lens systems and reflector-like mesa structures are used to reduce the losses, but so far it has not been possible, for example, to significantly increase the light extraction efficiency of organic LEDs (light emitting diodes) by more than 20%. For energy converters or signal generators such as solar cells or photodetectors based on organic semiconductors, the efficiency of the coupling is crucial for the quality of the entire component.

It is therefore the object of the present invention to provide a layer system for an optoelectronic component based on organic semiconductors, which exhibits an increased or decreased coupling efficiency of radiation compared to the prior art.

Solution to the problem is given in the claims, description and examples.

A solution of the object and subject of the invention is therefore an organic optoelectronic component following layer structure comprising, on a transparent substrate is a lower transparent electrode thereon at least one optoelectronically active organic layer, thereon an upper electrode, wherein in the transparent zone scattering centers are arranged through the total reflection is reduced.

In addition, the subject matter of the invention is a method for producing an organic optoelectronic device comprising the following method steps: a) application of a lower, at least semitransparent, electrode layer on an at least semitransparent one

Substrate, wherein at least in the transparent zone scattering centers are present, b) applying a functional optoelectronic-active organic layer c) applying a second electrode layer. The statistical scattering of the radiation at the scattering centers can improve the extraction or coupling efficiency by up to 40%.

In order to achieve a lower-loss outcoupling or coupling-in efficiency of the lower electrode, it is advantageous if the matrix material of the subsequent layer has a refractive index greater than or equal to that of the material of the lower electrode layer. Otherwise, additional radiation losses could occur by reducing the total reflection angle.

The "transparent zone" is preferably the area between the substrate, the lower transparent electrode and the optoelectronically active layer, wherein the transparent zone may be located within said layers, but also outside thereof, as well as one or more separate layers (s) In any event, the transparent zone refers to the area of the opto-electronic device in which the increase in efficiency for the device exhibits the best effect A device may also include multiple transparent zones.

An organic-based optoelectronic component is understood in particular to be an organic self-emitting diode (OLED), a photovoltaic cell or solar cell, a photodetector and / or an electrochromic component. The optoelectronically active layers of these components do not all interact with radiation of the same wavelength ranges, so that the refractive indices and / or ratios of the refractive indices of the layers specified here always refer to the component under consideration and the relevant radiation. For the sake of simplicity, all of the examples mentioned all refer to the wavelength of visible light, ie from approximately 400 to 750 nm.

Light extraction or coupling efficiency is simply referred to as the ratio of generated to outcoupled or incident to injected photons. According to an advantageous embodiment, the scattering centers are arranged in at least one separate layer of the transparent zone. In this case, the scattering centers can be arranged within a separate layer and within that of another layer or the substrate, or only in the separate layer.

According to a further advantageous embodiment of the invention düng the scattering centers are incorporated in the transparent zone mainly in the lower electrode layer.

It is particularly advantageous if the matrix material of the layer with the scattering centers is selected with respect to the refractive index such that the refractive index n of the scattering layer is greater than or equal to that of the lower electrode (n scattering layer ≥ n lower electrode). This prevents total reflection.

Hereinafter, the refractive index n of the lower electrode is referred to as n _e , where the subscript "e" stands for electrode, and an index for the refractive index of the matrix material is introduced "m" and the index "s" for the refractive index the scattering centers themselves. In the following, the symbols "n _e ";"N _m " and "n _s " are used for the respective refractive indices according to the above definitions.

In the litter layer a sufficient scattering effect is ensured by built-in the matrix material particles and / or pores. This preferably takes place when at least one of the following conditions is met: Firstly, it is advantageous if the scattering centers have a certain minimum size, for example in the range from 30 nm to 10 μm, in particular 100-700 nm and particularly preferably 200-300 nm, so that interaction with the radiation takes place to a high degree.

According to one embodiment of the invention, it may be advantageous that a more widely selected diameter distribution of Scattering centers is present, especially if it is not monochromatic radiation.

On the other hand, it is advantageous if the size distribution of the scattering centers is selected as closely as possible, for example with 7% deviation (see below), so that a uniform installation of the scattering centers in the layer and a uniform distribution within the layer is ensured. In addition, this is also advantageous in the formation of a homogeneous thick layer. According to a particular embodiment, therefore, less than 10%, in particular less than 7%, of the scattering centers of the scattering layers have scatter center diameters which deviate by more than 25% from the average scatter center diameter. More than 90% or 93% of the scattering centers of the scattering layer have a scatter center diameter that deviates less than 25% from the average scatter center diameter.

In order for the scattering centers within the layer to work optimally, it has been found that it is advantageous if a difference in the refractive indices between the scattering centers of the

Layer and the matrix material in which the scattering centers are embedded, which is about 0.05 or more, preferably about 0.2 or more, and more preferably about 0.5 or more, that is at least about +/- 0.05 or greater.

The matrix material, ie the material in which the scattering centers are embedded, here the scattering layer is for example a metal oxide such as titanium and / or zirconium oxide, but any other metal oxides or mixtures thereof and / or metal sulfides can also be used by mixtures targeted refractive indices of the matrix material can be adjusted.

On the one hand, the scattering centers may be discrete particles which are coated or uncoated, and on the other hand they may be pores in the matrix material which are empty, gas- and / or air-filled. As a so-called template material, for example, is a polymer, in particular such, or a mixture of different polymers (which are soluble in the coating solutions, sol-gel process can be applied and (those) when heated or when forming negative pressure, so for example when evaporating the solvent form by self-organization Einformungen. These polymers are also called porosity-causing polymers.

An embodiment of the invention is characterized in that the porosity-causing polymer is washed out after completion of the sol-gel process.

A preferred embodiment of the invention is characterized in that the porosity-causing polymer according to

Termination of the sol-gel process by means of heat treatment, in particular at a temperature of ≥ 80 ⁰ C to ≤ 100 ⁰ C, preferably washed with water.

The term "sol-gel process or sol-gel process" in

Meaning of the present invention means or includes in particular all processes and / or processes in which Metallpre- cursormaterialien, in particular metal halides and / or metal alkoxides, and mixtures thereof, are subjected in solution to a hydrolysis and subsequent condensation.

A preferred embodiment of the invention is characterized in that the porosity-causing polymer is burned out after completion of the sol-gel process, in particular at a temperature of ≥ 250 ⁰ C burned out.

A preferred embodiment of the invention is characterized in that the at least one porosity-causing component is a polymer, wherein the average molecular weight of the polymer is preferably> 5,000 Da to <500,000 Da, more preferably> 10,000 Da to <350,000 Da. A preferred embodiment of the invention is characterized in that the polymer is an organic polymer, preferably selected from the group comprising polyethylene glycol, polypropylene glycol, copolymers of polyethylene glycol and polypropylene glycol, polyvinylpyrrolidone, polyether, alkyl, cycloalkyl and / or aryl-substituted polyethers, polyesters alkyl-, cycloalkyl- and / or aryl-substituted polyesters, in particular polyhydroxybutyric acid or mixtures thereof.

General Groups / Molecule Definition: Within the specification and claims, general groups or molecules, such as e.g. As alkyl, alkoxy, aryl, etc. claimed and described. Unless otherwise described, the following groups within the generally described groups / molecules are preferably used in the context of the present invention:

Alkyl: linear and branched C 1 -C 8 -alkyls,

long-chain alkyls: linear and branched C5-C20 alkyls,

Alkenyl: C2-C6-alkenyl,

Cycloalkyl: C3-C8-cycloalkyl,

Alkoxide / alkoxy: Cl-C6-alkoxy, linear and branched,

long-chain alkoxide / alkoxy: linear and branched C5-C20 alkoxy,

Aryl: selected from aromatics having a molecular weight below 300 Da,

Polyether: selected from the group consisting of H- (O-CH ₂ -CH (R)) _n -OH and H- (O-CH ₂ -CH (R)) _n -H where R is independently selected from: hydrogen, alkyl , Aryl, halogen and n from 1 to 250, Substituted polyethers: selected from the group consisting of R ₂ - (O-CH ₂ -CH (R ₁ )) n -OR ₃ and R ₂ - (O-CH ₂ -CH (R ₂ )) _n -R ₃ where R i, R ₂ , R _{3 is} independently selected from: hydrogen, alkyl, long-chain alkyls, aryl, halogen and n is from 1 to 250,

Ether: The compound Ri-OR ₂ , wherein each Ri and R _{2 are} independently selected from the group consisting of hydrogen, halogen, alkyl, cycloalkyl, aryl, long chain alkyl.

Unless otherwise stated, the following groups / molecules are more preferred groups / molecules within the general group / molecule definition:

Alkyl: linear and branched C 1 -C 6 -alkyl,

Alkenyl: C3-C6 alkenyl,

Cycloalkyl: C6-C8-cycloalkyl,

Alkoxy, alkoxide: C 1 -C 4 -alkoxy, in particular isopropyl oxide,

long-chain alkoxy: linear and branched C5-C10 alkoxy, preferably linear C6-C8 alkoxy.

Polyether: selected from the group containing

H- (O-CH ₂ -CH (R)) _n -OH and H- (O-CH ₂ -CH (R)) _n -H wherein R is independently selected from: hydrogen, alkyl, aryl, halo and n of 10 to 250.

Substituted polyether: selected from the group consisting of R ₂ - (0-CH ₂ -CH (Ri)) _n -OR ₃ and R ₂ - (0-CH ₂ -CH (R ₂₎₎ _n -R ₃ wherein Ri, R ₂ , R _{3 is} independently selected from hydrogen, alkyl, long chain alkyl, aryl, halogen and n is from 10 to 250.

Furthermore, for example, polymers with incorporated polymer spheres, which are not soluble or poorly soluble in the solvents, so that they can act as a placeholder in applying and producing the layer are suitable, wherein they are subsequently removable, for example, again by mild heating and / or generation of negative pressure, removable. Needless to say, under the conditions in which these polymer beads are removable, the layer is stable. For example, polystyrene spheres or latex spheres can be used as polymer spheres. These are, for example, at temperatures below 250 ⁰ C, in which the layer materials are stable, washable.

For example, the scattering particles are of a different metal oxide than the matrix and have a visible light refractive index of about 1.5.

In a particular embodiment, the scattering particles of silicon dioxide. The scattering center refractive index n _s of silicon dioxide is about 1.5 for visible light. The use of silicon dioxide particles which have been prepared according to a method described by Stöber et al. developed methods (Journal of Colloid & Interface Science 1968 (26) pp. 62-69). Such silica-dioxide particles are synthesized from tetra-ethoxy-silane under ammoniacal conditions. The silicon dioxide particles thus obtained are not only present in a very narrow size distribution, but can be produced by appropriate process control in any sizes with particle diameters of about 30 nm to about 1 micron. They are present by electrostatic stabilization in a non-agglomerated state.

According to a particular embodiment, the scattering particles have a surface coating. The surfaces of the scattering particles are modified. For example, a sol-gel method is used to apply the electrode layer. By eliminating the electrostatic stabilization during introduction of the scattering particles into a coating sol used for the coating, an agglomeration and sedimentation of the scattering particles can be suppressed with the aid of a corresponding surface modification. Particularly good results are obtained with organic surface coatings with alkyl scored. According to a particular embodiment, therefore, the surface coating on at least one kind of hydrocarbon having aliphatic groups. The hydrocarbons with the aliphatic groups used can have heteroatoms. A surface coating with which very good results are achieved is based, for example, on methyl trichlorosilane.

In a special embodiment, besides the scattering particles as scattering centers, the scattering centers of the scattering layer have pores. The scattering centers are formed as pores. Only Steupartikel, only pores or scattering particles and pores can be present as scattering centers. The pores can form automatically during the manufacturing process of the litter layer. Preferably, the pores are generated via a template process. In this case, self-organizing polymers or polymer spheres are introduced into an initial layer of the litter layer and, after hardening of the litter layer, are removed or thermally removed. The pores, which can be evacuated, ie empty, or filled with a gas or a gas mixture (eg air), remain as scattering centers.

According to a particular embodiment, a smoothing layer is arranged within the component, in particular between the scattering layer and the transparent electrode layer. The smoothing layer compensates for surface roughness of the litter layer. In addition, it is suitable for reducing the cracking tendency of the ceramic coating during thermal curing. The smoothing layer provides an average roughness of preferably less than 50 nm. This makes it possible to realize a stack of layers with layer thicknesses in the nm range without causing short circuits or the like, for example due to so-called "spikes" between the layers, for example the use of polymeric film formers such as for example, polyethylene glycols, polyacrylics, etc. Alternatively or in addition to the application of a separate layer with scattering centers, it is also possible to introduce scattering centers directly into the electrode material, either in particle and / or in pore form. For this purpose, according to advantageous embodiments of the method according to the invention, sol-gel-based ITO materials and / or ITO dispersions which are made into a scattering electrode with corresponding particles or polymers are suitable. In this case, the matrix material is preferably processable from solution and can be prepared via a sol-gel process and deposited as a liquid. Application as a liquid opens up the application of many cost-effective and mass-producible manufacturing processes such as spraying, spin coating, spin coating, dipping, knife coating, flooding and many more.

According to an advantageous embodiment of the invention, the transparent lower electrode is made, for example, of indium tin oxide, in short, ITO. This material has a refractive index for visible light of about 1.9, for example, so that a material with a refractive index ≥ 1.9 is used as the matrix material of a scattering layer, for example a visible light-emitting or absorbing organic optoelectronic component. Further suitable electrode materials are tin oxide which is doped with fluorine (fluorine tin oxide, FTO), tin oxide which is doped with aluminum (aluminum tin oxide, AZO) or tin oxide, which is doped with antimony (Antomony-Tin-Oxide, ATO). The above-mentioned transparent electrode materials are for visible light, and among them, the luminescent light of the light-emitting diode each has an electrode material refractive index n _e of 1.8 to 2.0.

Thereafter, according to the preferred embodiments of the invention, the refractive index of the matrix material of the scattering layer (preferred condition n _m ≥ n _e ) and in turn the refractive index of the scattering centers (difference n _m to n _s at least 0, 05). A nontransparent counterelectrode is fundamentally uncritical in the sense of the invention, since it has little involvement in radiation losses (trapped modes) within the transparent zone of the component.

The substrate is preferably transparent and at least semitransparent, wherein glass, metal oxide (corundum), plastic (acrylate) and flexible plastics such as polyethylene films can be used.

Depending on the component, different materials and / or composite materials may be used as the optoelectronically active organic layer. The functional layer may also comprise multiple layers, just as it may consist of a blend of several materials. Furthermore, additives, solvents, particles and / or fillers may be mixed in, in particular also nanoparticles. For example, it is a polymer, but it can also organic tion tion materials, which are constructed with small molecules, are used.

The density or concentration of the scattering centers within the transparent zone can vary within wide limits. This depends on the one hand on whether the scattering centers are arranged in a separate layer or distributed arbitrarily in the transparent zone and on the other, this depends on the scattering particles and their matrix. It was found that, for example, a share area of 2% per irradiated electrode surface is a useful lower range limit, with no limits are set to the top, since maintaining the functionality of the component of any increase in concentration anyway in the way.

For the application of the layers, basically any method can be used, but preferred are solution-processable layers. Thus, metallic or inorganic layers can be separated from the gas phase, for example via Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD). According to a particular embodiment, a respective solution and / or a respective paste are used for applying the litter layer, the electrode layer, the functional layer and / or the further electrode layer. Such a method is suitable for both inorganic and organic layers.

With regard to the use of a corresponding solution, the use of a sol-gel method is particularly favorable. In each case a coating sol is applied. In particular, by stirring the scattering particles into the coating sol for the transparent electrode layer, there is an easy way of introducing scattering centers into the matrix material and statistically controlling the resulting

Integrate electrode layer. Titanium- and / or zirconium-based coating sols are used for this purpose, for example. For example, as placeholders for pores templates are used, as described in the 2007P14435 *.

After application of the coating brine or the coating brine, a heat treatment (tempering) takes place. As a result of the heat treatment, the corresponding layer is formed. In this case, a single temperature control step for all layers can be provided together. In particular, however, tempered in each case after the application of the respective coating sol. With regard to a litter layer configured with pores as scattering centers, the following procedure is particularly advantageous: The corresponding coating sol with polymer balls introduced is applied to a glass substrate and then tempered at temperatures so high that the introduced polymer spheres are thermally decomposed , The pores that form the scattering centers are formed. Subsequently, the coating sol for the electrode layer is applied and tempered again. Subsequently, the coating sol for the functional layer is applied. The subsequent tempering step can be carried out at lower temperatures be as the tempering step for the production of the litter layer.

In order to improve the processability of the solutions used for the preparation of the layers (for example, a viscosity of the coating sol), additives may be provided. However, it is also advantageous to use additives which positively influence the stability of the layers to be produced. Thus, according to a particular embodiment, at least one polymeric film former is used to apply the litter layer, the electrode layer, the functional layer and / or the further electrode layer. Such a film former prevents cracking in the respective layers. In addition, it is advantageous to add metal alkoxides with alkyl groups to the solutions used. Such metal alkoxides may further reduce cracking tendency in the formation of the layers.

With reference to several embodiments and the associated figures, the invention will be described in more detail below. The figures are schematic and do not represent true to scale figures.

FIG. 1 shows a section of a first exemplary embodiment of a light-emitting diode in a lateral cross-section.

FIG. 2 shows a detail of a second exemplary embodiment of a light-emitting diode in a lateral cross-section.

FIG. 3 shows a section of a light-emitting diode with a smoothing layer.

FIG. 4 shows the luminance of a scattering layer as a function of the layer thickness of the scattering layer and of the observation angle. The exemplary embodiments relate to a light-emitting diode 1 in the form of an OLED. The OLED has a layer stack 11 with a light-transparent electrode layer 12 for light, a further electrode layer 13 and an opto-electronically active layer 14 arranged between the electrode layers.

The transparent electrode layer 12 may vary in thickness by several tens to several hundreds of nm in its layer thickness, and is about 120 nm thick, for example. The electrode material of the transparent electrode layer 12 is ITO. In an alternative embodiment, the electrode material is ATO. The further electrode material of the electrode layer 13 is aluminum. The further electrode layer is, for example, also about the same thickness, ie about 120 nm thick. The further electrode layer or counterelectrode can be designed to be opaque, ie nontransparent or even transparent, so that, for example, a completely transparent OLED component results.

The at least 3 layers of substrate 16, transparent electrode 12 and optoelectronically active layer 14 with all optionally intervening optional layers together form the transparent zone, wherein a further transparent zone in the component may arise because the upper electrode layer is also transparent, so that the second transparent zone corresponds to the region between the optoelectronically active layer 14 and the upper, then also transparent electrode layer 13.

According to the first exemplary embodiment, the stack 11 is applied to a substrate surface 161 of a radiation-transparent glass substrate 16 (FIG. 1). Such a structure is referred to as a "bottom structure." The layer stack is applied indirectly to the substrate surface on a scattering layer 15. The scattering layer 15 is, for example, the same thickness as the electrode layer or thicker or of course, this also depends on the size of the scattering centers, especially if they are solid particles, and is about 120 nm thick here.

According to the second exemplary embodiment, the stack 11 is applied to the substrate via the further electrode layer 13 (FIG. 2). The scattering layer 15 is applied on the transparent electrode layer 12. The radiation is first coupled into the transparent electrode layer 12 starting from the functional layer. From there, it enters the litter layer 15. Starting from the litter layer, the radiation is decoupled into the environment.

In the matrix material 152 of the scattering layer scattering centers 153 are distributed, for example in the form of scattering particles of silicon dioxide. The scattering particles have a surface coating of methyl trichlorosilane. The average scatter center diameter is about 100 nm. More than 90% of the scattering particles have a scatter center diameter in the range of about 75 nm to about 125 nm. In an alternative embodiment, the scattering centers are in the form of air, that is, they form the pores 153 of the matrix material 152 with the specified average scatter center diameter.

According to a further embodiment, the scattering center diameters vary within wide limits, in particular when monochromatic radiation is not present, since with a desired interaction there is a direct relationship between the size of the scattering centers and the wavelength of the radiation.

The functional layer 14 consists for example of two partial layers, a hole-line layer 141 of PEDOTiPSS and an emitter layer 142. The emitter layer is the opto-electronically active layer. By electrically driving the electrode layers (the transparent electrode layer 12 functions, for example, as an anode, the electrode layer 13 then acts as a cathode), the functional layer is excited to emit radiation. Due to the scattering layer, the probability of the occurrence of multiple reflections of the luminescent light or even of total reflection is reduced, so that the radiation can be coupled out of the transparent electrode layer into the environment or into the glass substrate with high efficiency. The internal losses in terms of radiation are significantly reduced. The electrode layer 13 acts as a mirror for the radiation, so that it can be coupled out of the stack 11 of the OLED with high efficiency and very low losses.

According to a further embodiment, a smoothing layer 17 for reducing the surface roughness is arranged between the scattering layer 15 and the transparent electrode layer 12 (FIG. 3).

To prepare the layers, the sol-gel method is used. For this purpose, corresponding coating sols are applied in a first process step, which are then tempered. During tempering, the corresponding layers are formed. In order to avoid cracking, polymeric film formers and / or metal alkoxides are used in the coating sols.

To demonstrate the suitability of a litter layer with a metal oxide as a matrix material, a thin layer with Tiθ2 was prepared as a matrix material. TiO 2 was either obtained commercially or prepared as follows:

1/50 mole of titanium isopropoxide and 1/500 mole of octyl triethoxy silane are dissolved in 16/50 mole of isopropyl alcohol (IPA) for 30 minutes with stirring (solution). Dissolve 0.5 g of Brij56® in 2/50 mol of IPA and add to the solution. After your further rest A mixture of 2 g of 5N HCl and 2/50 mol of EtOH was slowly added dropwise with stirring.

The preparation of the Tiθ ₂ ~ particles was carried out by dissolving 6 g of tetra-ethoxy-silane in 50 g of ethanol. This mixture is heated to 60 ^° C. with stirring. Subsequently, 6 g of 25% ammonia solution are added. After stirring for a further 3h, the solution is cooled to room temperature. The solution is mixed with 3 ml of trichloro-methyl-silane and shaken. The particles produced settle on the bottom of the container.

The supernatant liquid is poured off and refilled with ethanol and shaken out again. This washing process is repeated several times. The settled particles are removed from the solution using a pipette and added with stirring to the coating sol for the litter layer. The layer application takes place by means of dip coating. This was followed by a tempering at 400 ⁰ C for 15 min.

The scattering effect of the sample was resolved as a function of the angle (FIG. 4). It shows a scattering effect, which increases with increasing thickness of the coating (set by multiple coating xl, x2, x4, etc.), which is equivalent to the increase of the scattering events per irradiated area.

In summary, the following advantages of the invention should be emphasized:

- Through the litter layer, it is possible to increase the luminous efficacy of the light-emitting diode significantly.

- For the manufacturing process of the layer stack of the light-emitting diode can be used on known methods, in particular sol-gel method.

- The production of the light-emitting diode is inexpensive and can be carried out on a large scale.

Claims

claims

1. organic optoelectronic component comprising the following layer structure, on a transparent substrate is a lower transparent electrode thereon at least one optoelectronically active organic layer, thereon an upper electrode, wherein in the transparent zone scattering centers are arranged.

2. Component according to claim 1, wherein the scattering centers are arranged in the transparent electrode.

3. Component according to one of claims 1 or 2, wherein the scattering centers are arranged in a separate layer.

4. Component according to one of the preceding claims, wherein the refractive index of the optoelectrically active layer within the transparent zone of the component has the smallest refractive index for the relevant radiation.

5. The component according to claim 4, wherein the refractive index increases from the optoelectronically active layer to the substrate or the encapsulation from layer to layer, or at least remains the same.

6. Component according to one of the preceding claims, wherein the scattering centers have a minimum size in the range of 30 nm to 10 microns.

7. Component according to one of the preceding claims, wherein the size distribution of the scattering centers is not more than 7%.

8. The component according to one of the preceding claims, wherein the difference of the refractive indices between the scattering centers and the matrix material in which the scattering centers are embedded, is 0.05 or more.

9. Component according to one of the preceding claims, wherein the matrix material of the scattering layer is a metal oxide.

10. Component according to one of the preceding claims, wherein the scattering centers are discrete particles or pores.

11. Component according to one of the preceding claims, wherein the scattering centers are embedded in the form of pores in a template material.

12. Component according to one of the preceding claims, wherein the scattering centers comprise particles of silicon dioxide.

13. Component according to one of the preceding claims, wherein the scattering centers in the form of particles have a surface coating.

14. Component according to one of the preceding claims, which has a smoothing layer (17).

15. A method for producing an organic optoelectronic component comprises the following method steps comprising: a) applying a lower transparent electrode layer on a transparent substrate, wherein scattering centers are present at least in the transparent zone, b) applying a functional optoelectronically active organic layer c) applying a second electrode layer.

16. The method of claim 15, nor the process step d) applying a smoothing layer comprising.

17. The method according to any one of claims 15 or 16, wherein at least one layer of solution is processed.