Optoelectronic component

Abstract

Optoelectronic device (1) in the form of an organic solar cell comprising at least one photoactive layer (5) of small molecules, non-polymeric organic molecules with monodisperse molar masses between 100 and 2000, which is arranged between an electrode (3) and a counter electrode (7), wherein the photoactive layer (5) is a multi-layer composite comprising at least a first material, a second material and a third material, wherein the first material is a donor made of small molecules, the second material is an acceptor from the group of fullerenes or fullerene derivatives, wherein the donor and the acceptor form a donor-acceptor system, and at least one third material, which is configured to influence the crystallization tendency of the donor and / or acceptor, wherein the third material is a crown ether selected from a group of the general formula (Ia) or (Ib) where Ar = phenyl,Biphenyl, triphenyl, naphthyl, binaphthyl, 3-6 fused phenyl rings, anthracenyl, phenanthrenyl, pyrenyl, heterocyclic thiophene, pyrrole, furan, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyrimidine, pyrazine, benzothiophene, benzopyrrole, benzofuran, benzothiophene, benzopyrrole, benzofuran, benzooxazole, benzothiazole, thienothiophene, thienopyrrole, thienofuran, 3-6 fused heterocycles, dithienothiophene, dithienopyrrole, dithienobenzene, dithienocyclopentadiene, dipyrrolobenzene, ether bridges in 1,2-, 1,3- and 1,4-linkages at the respective phenyl ring (ortho, meta- and para-positions), naphthyl ring, fused Phenyl ring as well as heteroaryl ring and annelated heteroaryl ring, m and n independently 3,4,5,6 for formula (Ia) and m and n independently 1,2,3,4,5,6 for formula (Ib), undo and p independently 0,1,2,3,4,5,6.

Description

The invention relates to an optoelectronic component having a photoactive layer which is arranged between an electrode and a counter electrode.Optoelectronic components, such as solar cells or LEDs, TFTs, etc., are nowadays widely used in the common and industrial fields. For example, thin-film solar cells are known which have a flexible configuration and thus allow arrangement on curved surfaces. Such solar cells preferably have active layers of amorphous silicon (a-Si) or CIGS (Cu(In,Ga)(S,Se) 2) in this case. Disadvantages of these thin-film solar cells are the high production costs, which are primarily caused by the materials.Furthermore, solar cells with organic active layers which are of flexible configuration (Konarka-Power Plastic Series) are also known. The organic active layers can be constructed from polymers (e.g. U.S. Pat. No. 7,825,326 B2) or small molecules (e.g. EP 2 385 556 A1). While polymers are characterized in that they cannot be vaporized and can therefore only be applied from solutions, small molecules are capable of being vaporized.The advantage of such devices on an organic basis compared to conventional devices on an inorganic basis (semiconductors such as silicon, gallium arsenide) is the in some cases extremely high optical absorption coefficients (up to 2×10 5 cm -1), so that it is possible to produce very thin solar cells with low material and energy requirements. Other technological aspects are the low cost, the possibility of manufacturing flexible large area components on plastic foils, and the almost unlimited variation possibilities and the unlimited availability of organic chemistry. A further advantage lies in the possibility of being able to produce transparent components which can be used, for example, in glass applications.A solar cell converts light energy into electrical energy. The term photoactive in solar cells denotes the conversion of light energy into electrical energy. In contrast to inorganic solar cells, in organic solar cells, free charge carriers are not generated directly by the light, but excitons, i.e. electrically neutral excitation states (bound electron-hole pairs), are initially formed. Only in a second step are these excitons separated into free charge carriers which then contribute to the electrical current flow.One possible implementation of an organic solar cell that has already been proposed in the literature consists of a pin diode having the following layer structure:0. Carrier, substrate,1. Base contact, usually transparent,2. p-layer(s),3. i-layer(s),4. n-layer(s),5. Cover contact.Here, n or p means an n- or p-doping which leads to an increase in the density of free electrons or holes in the thermal equilibrium state. However, it is also possible for the n-layer(s) or p-layer(s) to be at least partially nominally undoped and to have preferably n-conducting or preferably p-conducting properties only on account of the material properties (e.g. different mobilities), on account of unknown impurities (e.g. remaining residues from the synthesis, decomposition products or reaction products during the layer production) or on account of influences of the environment (e.g. adjacent layers, in-diffusion of metals or other organic materials, gas doping from the environment). In this sense, such layers are primarily to be understood as transport layers. The designation i-layer, in contrast, designates a nominally undoped layer (intrinsic layer). One or more i-layers can consist here of layers both of one material and of a mixture of two or more materials (so-called interpenetrating networks or bulk heterojunction). The light incident through the transparent base contact generates excitons (bound electron-hole pairs) in the i-layer and in the n / p-layer, respectively. These excitons can only be separated by very high electric fields or at suitable interfaces. In organic solar cells, sufficiently high fields are not available, so that all promising concepts for organic solar cells are based on exciton separation at photoactive interfaces. The excitons are diffused to such an active interface where electrons and holes are separated from each other. The material which takes up the electrons is referred to as acceptor and the material which takes up the hole is referred to as donor (or donor). The separating interface may be between the p-(n-) layer and the i-layer or between two i-layers. In the built-in electric field of the solar cell, the electrons are now transported away to the n-region and the holes are transported away to the p-region. The transport layers are preferably transparent or largely transparent materials with a large band gap (wide gap), as described, for example, in WO 2004 / 083 958 A2. Here, wide-gap materials are materials whose absorption maximum lies in the wavelength range <450 nm, preferably <400 nm.Possibilities for adapting the LUMO levels or the HOMO levels are known to the person skilled in the art, very many organic materials having different levels of the energy levels of the HOMOs and LUMOs being known. The adaptation is therefore carried out in such a way that a material is selected and used which has the desired position of the energy levels of the HOMO or LUMO. Furthermore, for example, by the incorporation of electron-withdrawing or electron-pushing groups, the HOMO and LUMO levels of organic materials can be lowered or increased and thus the adaptation of a material can take place according to the requirements.Since excitons are always first generated by the light and no free charge carriers yet, the low-recombination diffusion of excitons to the active interface plays a critical role in organic solar cells.If the i-layer is a mixed layer, the task of light absorption takes over either only one of the components or also both. The advantage of mixed layers is that the excitons generated need only travel a very short distance until they reach a domain boundary where they are separated. The removal of the electrons or holes is effected separately in the respective materials. Since the materials are in contact with one another everywhere in the mixed layer, it is decisive in this concept that the separated charges have a long lifetime on the respective material and that continuous percolation paths for both types of charge carrier are present from each location towards the respective contact.DE 10 2010 033 026 A1 discloses a method for controlling the morphology during production of a plastic solar cell or polymer cell, with which D-A molecules deposited from solution are built up as self-aggregating monolayers (SAM). The D-A molecules are donor-acceptor systems which consist of a polymer as donor and fullerene derivatives as acceptor.US 2013 / 0 140 527 A1 discloses a material mixture of a hole-blocking material and an electron injection / electron transport polymer in which crown ethers are chemically bonded with interchelated metal ions, and the use thereof in optoelectronic components.DE 10 2004 021 989 A1 discloses organic electronic devices for both light emission and charge generation. The advantageous effect of inclusion compounds for charge transport is described, with crown ethers being mentioned in a long list of possible substances for use as inclusion compound.US 2013 / 0 087 778 A1 discloses organic luminescence devices, so-called OLEDs. Crown ethers are used to improve electron transport properties.Up to now, in the region of the small molecules, the absorber layer thicknesses are limited to approximately 30-40 nm (in the best case 60 nm), whereas in the polymer range up to 200 nm with still good fill factor (FF) (>60%) are possible. The background is the poorer charge carrier transport in SM-OPV (organic solar cells with small molecules), since there is no on-chain transport in contrast to polymers. In the field of organic solar cells with small molecules, the problem has been solved up to now by ever higher extinction coefficients (in solution up to 100,000 and above), which have led to good efficiencies with good FF. However, due to the cyanine limit, this is not infinitely increaseable. Therefore, solutions are sought for making donor-acceptor mixed layers (so-called bulk heterojunctions, BHJ) thicker in order to increase the quantum yield.The object of the present invention is therefore to specify an optoelectronic component and a method for producing an optoelectronic component which has an improved quantum yield.The object is achieved by an optoelectronic component according to claim 1. Advantageous embodiments are specified in the dependent claims.An increased quantum yield could be achieved by increasing the layer thickness of the photoactive layer. However, the problem here is the torsion which occurs in the oligomer building blocks and too strong crystallization, which often causes short circuits.An optoelectronic component comprising at least one photoactive layer is disclosed, wherein the photoactive layer comprises a multiple mixed layer containing at least three materials, wherein at least one organic material is made of small molecules, wherein at least one material is a donor and at least one material is an acceptor, wherein the donor and the acceptor form a donor-acceptor system with at least one third material which is designed such that it influences the tendency of the donor and / or acceptor to crystallize.For the purposes of the present invention, small molecules are understood to mean non-polymeric organic molecules having monodisperse molar masses between 100 and 2000, which are present in the solid phase under normal pressure (atmospheric pressure of the atmosphere surrounding them) and at room temperature. In particular, these small molecules can also be photoactive, wherein photoactive is understood to mean that the molecules change their state of charge when supplied with energy. In this case, energy supply is understood to mean both light energy supply, for example visible light, UV light or else electrical energy supply.According to the invention, the optoelectronic component in the form of an organic solar cell comprises at least one photoactive layer made of small molecules, non-polymeric organic molecules with monodisperse molar masses between 100 and 2000, which is arranged between an electrode and a counter electrode, wherein the photoactive layer comprises a multiple mixed layer containing at least a first material, a second material and a third material, wherein the first material is a donor made of organic material made of small molecules, wherein the second material is an acceptor from the group of fullerenes or fullerene derivatives, wherein the donor and the acceptor form a donor-acceptor system, and at least the one third material which is designed such that it influences the tendency of the donor and / or acceptor to crystallize, wherein the third material is a crown ether selected from a group of the general formula (Ia) or (Ib) with Ar=phenyl, biphenyl, triphenyl, naphthyl, binaphthyl, 3-6 annellated phenyl rings, anthracenyl, phenanthrenyl, pyrenyl, hetar=thiophene, pyrrole, furan, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyrimidine, pyrazine, benzothiophenes, benzopyrrole, benzofuran, benzothiophene, benzopyrrole, benzofuran, benzoxazole, Benzothiazol,Thienothiophene thienopyrrole, thienofuran, 3-6 annellated heterocycles, Dithienothiophene, dithienopyrrole, dithienobenzene, Dithienocyclopentadiene dipyrrolobenzene, ether bridges in 1,2-, 1,3- and 1,4-linkage on the respective phenyl ring (ortho, meta and para position), naphthyl ring, fused phenyl ring and heteroaryl ring and fused heteroaryl ring, m and n independently of one another are 3,4,5,6 for formula (Ia) and m and n independently of one another are 1,2,3,4,5,6 for formula (Ib), and o and p independently of one another are 0,1,2,3,4,5,6.In one embodiment of the invention, the third material has an energy level at which the amount of LUMO<= the LUMO of the acceptor and the HOMO is >= the amount of HOMO of the donor. The difference of HOMO and LUMO of the third material is therefore greater than or at least equal to the difference between the HOMO of the donor and the LUMO of the acceptor, as shown in Fig. 20.The terms "HOMO" and "LUMO" are understood as meaning, as is customary in chemistry, as highest occluded molecular orbital and lowest unoccupated molecular orbital. The term refers to individual molecules as well as to solid bodies or material films. The energy positions of HOMO and LUMO can be determined here as known to the person skilled in the art, for example by cyclic voltammetry (CV) or ultraviolet photoelectron spectroscopy (UPS).In a further embodiment of the invention, the third material has an energy level, wherein preferably the amount of LUMO of the third material is 0.3 eV lower than the LUMO of the acceptor material of the photoactive layer and / or the amount of HOMO of the third material is 0.3 eV above the amount of the energy level of HOMO of the donor material of the photoactive layer.In a further embodiment of the invention, the proportion of the third material in the photoactive layer is 0.1% by weight<x<30% by weight, preferably 0.1% by weight<x<20% by weight, particularly preferably 0.1% by weight<x<10% by weight.In a further embodiment of the invention, the third material simultaneously improves the charge transport within the photoactive layer.In a further embodiment of the invention, at least one donor material of the photoactive layer is an oligomer.Oligomers in the context of the invention are understood to mean non-polymeric organic molecules having monodisperse molar masses between 100 and 2000, which are present in the solid phase under normal pressure (atmospheric pressure of the atmosphere surrounding them) and at room temperature.In a further embodiment of the invention, at least one donor material D1 of the photoactive layer is an oligomer, wherein the amount of HOMO of the donor material D1 is equal to the amount of HOMO of the third material and the amount of LUMO of the donor material D1 is equal to the amount of LUMO of the third material.In another embodiment of the invention, the third material is an oligomer.In a further embodiment of the invention, the third material is formed such that crystallization of donor and / or acceptor is avoided. The third material can be a hole conductor, an electron conductor or an ambipolar transporting material, wherein the latter can also be a mixture of electron and hole conductors, for example.In a further embodiment of the invention, the third material minimizes a crystallization of the donor and / or acceptor phase on account of its molecular structure. Due to the better mixing of donor and acceptor, more excitons can reach a separating interface and be separated into charge carriers and thus contribute to the current.In a further embodiment of the invention, the molecular structure of the third material is largely similar to the molecular structure of the donor material D 1, as a result of which the third material acts as a lattice defect in the donor material D 1, such that the donor material D 1 does not crystallize too strongly as a pure phase.A lattice defect (also lattice defects or crystal defects) is understood to mean any irregularity in an otherwise periodic crystal lattice. The existence of lattice defects distinguishes the real crystal from the theoretical model of the ideal crystal. Lattice defects are of fundamental importance for many properties of a crystal, in particular for chemical reactivity, mass transfer and diffusion in the crystal and for its mechanical properties. The lattice defects are classified on the basis of the spatial extent of the defect region. The number of spatial dimensions in which the lattice defect has more than atomic extent is identified. In this way, zero to three-dimensional lattice defects are distinguished.In one embodiment of the invention, the molecular structure of the third material is formed such that the third material causes a lattice defect in the donor and / or acceptor material.In one embodiment of the invention, the molecular structure of the third material is largely similar to the structure of the acceptor material A 1, whereby the third material acts as a lattice defect in the acceptor material A 1, so that the acceptor material A 1 does not crystallize too strongly as a pure phase.In a further embodiment of the invention, the third material is formed such that the crystallization of donor material and / or acceptor material is improved. In this case, the third material provides phase separation and thus improves charge transport in the individual phases by creating more closed conduction paths. The improved phase separation can be demonstrated, for example, on the basis of a reduced photoluminescence signal of the 3-fold mixed layer compared to that without a third material.In another embodiment of the invention, the third material is selected such that the third material sets a minimum distance between the acceptor and donor, wherein the third material simultaneously contributes a phase separation of the acceptor and donor. Thus, the problem of "geminal recombination" can be reduced. Geminal recombination is understood in the sense of the invention to mean the recombination of already separated charge carriers with themselves.In a further embodiment of the invention, the third material has in its molecular structure a first region which is formed to be fullereneophilic and a second region which is formed to be fullereneophobic, wherein the first and second regions are formed to be spatially separated. For the purposes of the invention, "fullereneophilic" is a molecular structure or at least a part of a molecular structure which preferably attaches to fullerenes (C 60, C 70, etc.). For the purposes of the invention, "fullerene phob" is understood to mean a molecular structure or at least a part of a molecular structure which preferably does not accumulate on fullerenes (C 60, C 70, etc.).In a further embodiment of the invention, the optoelectronic component has more than one photoactive layer between the electrode and the counter electrode. The component can be designed, for example, as a tandem or triple cell. This is particularly advantageous since the incident light passes through a plurality of photoactive layers within the component. The different absorber layers are particularly advantageously matched to one another, wherein the absorber layers have different absorption maxima. This enables efficient use of the incident light.In a further embodiment of the invention, at least one of the photoactive layers comprises, as acceptor, a material from the group of fullerenes or fullerene derivatives.In a further embodiment of the invention, at least one doped, partially doped or undoped transport layer is arranged between the electrode and the counter electrode.In a further embodiment of the invention, the component is a pin single, pin tandem cell, pin multiple cell, nip single cell, nip tandem cell or nip multiple cell.In a further embodiment of the invention, the component consists of a combination of nip, ni, ip, pnip, pni, pip, nipn, nin, ipn, pnipn, pnin or pipn structures, in which a plurality of independent combinations containing at least one i-layer are stacked one above the other.In particular, dibenzo-crown ethers and dinaphtho-crown ethers and mixed benzo / naphtho-crown ethers are used. Preference is given to compounds having the following structures: or or or or or where in each case: n and m are selected independently of one another from 3, 4 or 5, and R 1, R 2, R 3, R 4, R5, R6, R7, R8, R9, R10, R 11 and R 12 independently of one another selected from H, CH 3, C 2 H 5, C 3 H 7, C 4 H 9, C 5 H11, C6H13, isobutyl, CF3, C2F5, C3F7, C4F9, C 5 F 11, C 6 F 13, OH, O-CH 3, CH 2- O-CH 3, CH 2- O-CH 2- CH 3, CN, phenyl, thiophene.In one embodiment of the invention, the crown ethers have the following general formula (II): where Ar=phenyl, naphthyl, biphenyl, triphenyl, naphthyl, binaphthyl, 3-6 fused phenyl rings, anthracenyl, phenanthrenyl, pyrenyl, hetar=thiophene, pyrrole, furan, thienothiphene, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyrimidine, pyrazine, benzothiophenes, benzopyrrole, benzofuran, benzothiophene, benzopyrrole, benzofuran, benzoxazole, benzothiazole, thienothiophenes, thienopyrrole, thienofuran, thienofuran, 3-6 fused heterocycles, dithienothiophene, dithienopyrrole, dithienobenzene, Dithienocyclopentadiene dipyrrolobenzene, ether bridges in 1,2-, 1,3- and 1,4-linkage on the respective phenyl ring (ortho, meta and para position), naphthyl ring, fused phenyl ring and heteroaryl ring and fused heteroaryl ring, m and n independently of one another are 1,2,3,4,5,6, p and q independently of one another are 1,2,3,4,5,6.Particular preference is given to compounds having the following structures: In one embodiment of the invention, the crown ethers are selected from a group consisting of aryl and heteroaryl crown ethers and fused aryl and fused heteroaryl crown ethers, preferably diaryl and diheteroaryl crown ethers and mixed aryl and heteroaryl crown ethers, particularly preferably dibenzo crown ethers, dinaphtho crown ethers and mixed benzonaphtho crown ethers. An aryl crown ether consists of at least one aryl group, but may also have a bi-, tri- and polycyclic aromatic hydrocarbon group. At this base, two carbon atoms of the aryl backbone are linked annularly to monoethoxy, diethoxy, triethoxy, tetraethoxysilane, pentaethoxy and hexaethoxy groups. An fused aryl crown ether consists of at least one bicyclic aromatic hydrocarbon group, but may also have a tri- and polycyclic aromatic hydrocarbon group. At this base, two carbon atoms of the fused backbone are linked annularly to monoethoxy, diethoxy, triethoxy, tetraethoxysilane, pentaethoxy and hexaethoxy groups. An fused heteroaryl crown ether consists of at least one heteroaryl ring to which at least one benzene ring or a further heteroaryl ring are fused, but can also have a tri- and polycyclic heteroaromatic hydrocarbon group. At this base, two carbon atoms of the fused backbone are linked annularly to monoethoxy, diethoxy, triethoxy, tetraethoxysilane, pentaethoxy and hexaethoxy groups. A diaryl crown ether consists of two unnenellated (separate) aryl groups linked together in the form of a crown via two alkoxy bridges. These alkoxy moieties consist of one to six ethoxy groups. An fused diaryl crown ether consists of two fused aryl groups which are linked to one another in the form of a crown via two alkoxy bridges. These alkoxy moieties consist of one to six ethoxy groups. An fused diheteroaryl crown ether consists of two fused heteroaryl groups which are linked to one another in the form of a crown via two alkoxy bridges. These alkoxy moieties consist of one to six ethoxy groups. An aryl-heteroaryl-crown ether consists of both an aryl group and a heteroaryl group, which are linked to one another in the form of a crown via two alkoxy bridges. These alkoxy moieties consist of one to six ethoxy groups.A sorbitol is also disclosed as the third material. Preference is given to compounds having the following structures: where R1and R2are independently selected from H, CH 3, C 2 H 5 and A quinacridone is also disclosed as the third material. Preference is given to compounds having the following structures: or As a third material, bis(4-(tert-butyl)benzoateo-O)hydroxyaluminum having the following structure is also disclosed: Also disclosed as a third material is a triphenyl having the following structure: wherein R1to R6are independently selected from H, OH, OCH 3, OOCH 3, wherein at least three oxygens are contained in the molecule. Preference is given to compounds having the following structures: Preferred developments of the invention result from the combinations of the claims or individual features thereof.The invention will be explained in detail below with reference to some exemplary embodiments and figures. The exemplary embodiments are intended to describe the invention without limiting it. They show in FIG. 1 shows a schematic illustration of a component according to the invention, in FIG. 2 shows a current-voltage characteristic curve of a component having two materials in the photoactive layer, in FIG. 3 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 2, but having three materials in the photoactive layer, compound (I) being used as the third material, FIG. 4 shows a current-voltage characteristic curve of a component having two materials in the photoactive layer, in FIG. 5 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 4, but having three materials in the photoactive layer, compound (I) being used as the third material, FIG. 6 shows a current-voltage characteristic curve of a component having two materials in the photoactive layer, in FIG. 7 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 6, but having three materials in the photoactive layer, compound (I) being used as the third material, in FIG. 8 shows a current-voltage characteristic curve of a component with two materials in the photoactive layer, in FIG. 9 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 8, but having three materials in the photoactive layer, compound (II) being used as the third material, FIG. 10 shows a current-voltage characteristic curve of a component with two materials in the photoactive layer, in FIG. 11 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 10, but having three materials in the photoactive layer, compound (V) being used as the third material, FIG. 12 shows a current-voltage characteristic curve of a component with two materials in the photoactive layer, in FIG. 13 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 12, but having three materials in the photoactive layer, compound (VI) being used as the third material, in FIG. 14 shows a current-voltage characteristic curve of a component having two materials in the photoactive layer, deposited at a substrate temperature of 70° C. FIG. 15 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 14, but having three materials in the photoactive layer, compound (III) being used as the third material and the deposition taking place at room temperature, in FIG. 16 shows a current-voltage characteristic curve of a component with two materials in the photoactive layer, deposited at a substrate temperature of 70° C. and in FIG. 17 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 16, but having three materials in the photoactive layer, compound (I) being used as the third material and the deposition taking place at room temperature, FIG. 18 shows a current-voltage characteristic curve of a component having two materials in the photoactive layer, deposited at a substrate temperature of 70° C. FIG. 19 shows a current-voltage characteristic curve of a component having the same layer structure as shown in FIG. 18, but having three materials in the photoactive layer, compound (VI) being used as the third material and the deposition having taken place at room temperature and in FIG. 20 is a schematic illustration of an energy scheme with three materials.In an exemplary embodiment of the invention, FIG. 1 schematically illustrates a component 1, which is embodied, for example, as an organic solar cell. The component 1 is arranged on a transparent substrate 2, which is preferably flexible, for example in the form of a film. Arranged on the substrate 2 is an electrode 3 which is made of metal, a conductive oxide, in particular ITO, ZnO:Al or other TCOs or a conductive polymer, such as PEDOT:PSS or PANI. A charge carrier transport layer 4 is arranged on the electrode 3, which is formed, for example, as an electron or hole transport layer. Arranged on this charge carrier transport layer 4 is a photoactive layer 5 which comprises at least one donor material and one acceptor material which together form a donor-acceptor system. In addition, the photoactive layer comprises a third material with a proportion of 0.1 wt %<x<10 wt %. This third material is selected from a group of materials according to the invention and not according to the invention consisting of crown ethers, triphenyls, sorbitols, quinacridones, bis(4-(tert-butyl)benzoateo-O)hydroxyaluminum. A further charge carrier transport layer 6 is arranged on the photoactive layer 5. This charge carrier transport layer 6 is likewise designed as an electron or hole transport layer, wherein the charge carrier transport layer 6 is designed to be complementary to the charge carrier transport layer 4. On this charge carrier transport layer 6, a counter electrode 7 is arranged, which is formed, for example, from a metal, such as Al.In a further exemplary embodiment, the photoactive component 1 has, for example, the following structure:ITO / C60 / Mixed photoactive layer / BPAPF (9,9-bis[4-(N,N-bis-biphenyl-4-yl-amino)phenyl]-9H-fluorene) / BPAPF:NDP9 / NDP9 / Auwherein the photoactive mixed layer comprises as third material one of the following compounds in an admixture of <7%): Compound (I) (Invention)Compound (II) (Invention)Compound (III) (Invention)Compound (IV) (noninventive)Compound (V) (noninventive)Compound (VI) (noninventive)In a further exemplary embodiment according to the invention, FIGS. 2 and 3 graphically show the measurement results for a component 1 having a photoactive layer 5 having a donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 2 shows the current-voltage characteristic curve of a component 1 with a donor acceptor system and FIG. 3 shows a current-voltage characteristic curve for a component with a photoactive layer comprising the donor acceptor system and compound (I). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (I).This shows an increase in the filling factor (FF) from 46% to 58.6%, caused by the admixture of the compound (I).From the comparison of the fill factors (FF), it can be seen that the addition of the third material has a substantial influence on the generated current.In a further exemplary embodiment according to the invention, FIGS. 4 and 5 graphically show the measurement results for a component 1 having a photoactive layer 5 with another donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 4 shows the current-voltage characteristic curve of a component 1 having a donor acceptor system and FIG. 5 shows a current-voltage characteristic curve for a component having a photoactive layer comprising the donor acceptor system and compound (I). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (I). This shows an increase in the filling factor (FF) from 48.8% to 65.7%, caused by the admixture of the compound (I).In a further exemplary embodiment according to the invention, FIGS. 6 and 7 graphically show the measurement results for a component 1 having a photoactive layer 5 with a third donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 6 shows the current-voltage characteristic curve of a component 1 with a donor acceptor system and FIG. 7 shows a current-voltage characteristic curve for a component with a photoactive layer comprising the donor acceptor system and compound (I). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (I). This shows an increase in the filling factor (FF) from 50.7% to 62.7%, caused by the admixture of the compound (I).In a further exemplary embodiment according to the invention, FIGS. 8 and 9 graphically show the measurement results for a component 1 having a photoactive layer 5 having a donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 8 shows the current-voltage characteristic curve of a component 1 with a donor acceptor system and FIG. 9 shows a current-voltage characteristic curve for a component with a photoactive layer comprising the donor acceptor system and compound (II). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (II). This shows an increase in the filling factor (FF) from 46% to 50.6%, caused by the admixture of the compound (II).In a further exemplary embodiment not according to the invention, FIGS. 10 and 11 graphically show the measurement results for a component 1 having a photoactive layer 5 having a further donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 10 shows the current-voltage characteristic curve of a component 1 with a donor acceptor system and FIG. 11 shows a current-voltage characteristic curve for a component with a photoactive layer comprising the donor acceptor system and compound (V). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (V). This shows an increase in the filling factor (FF) from 48.8% to 60.2% caused by the admixture of the compound (V).In a further exemplary embodiment not according to the invention, FIGS. 12 and 13 graphically show the measurement results for a further component 1 having a photoactive layer 5 having a donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 12 shows the current-voltage characteristic curve of a component 1 with a donor acceptor system and FIG. 13 shows a current-voltage characteristic curve for a component with a photoactive layer comprising the donor acceptor system and compound (VI). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (VI). This shows an increase in the filling factor (FF) from 48.8% to 60.3% caused by the admixture of the compound (VI).In a further exemplary embodiment according to the invention, FIGS. 14 and 15 graphically show the measurement results for a further component 1 having a photoactive layer 5 having a donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. FIG. 14 shows the current-voltage characteristic curve of a component 1 with a donor acceptor system and FIG. 15 shows a current-voltage characteristic curve for a component with a photoactive layer comprising the donor acceptor system and compound (III). The photoactive layer 5 of the components differs here only with regard to the admixture of the compound (III). This shows an increase in the filling factor (FF) from 60.0% to 65.2% caused by the admixture of the compound (III).In a further exemplary embodiment according to the invention, FIGS. 16 and 17 graphically show the measurement results for a component 1 having a photoactive layer 5 having a donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at a substrate temperature of 70° C. in FIG. 16 and at room temperature in FIG. 17. FIG. 16 shows the current-voltage characteristics of a component 1 having a donor acceptor system and FIG. 17 shows a current-voltage characteristics for a component having a photoactive layer comprising the donor acceptor system and compound (I). The photoactive layer 5 of the components differs here with regard to the admixture of the compound (I) and the substrate temperature during the deposition of the photoactive layer 5. By admixing the compound (I), the same fill factor can thus be achieved at lower substrate temperatures as in the case of heated substrates without admixture. By the admixture, thus simplified conditions can be achieved during the deposition.In a further exemplary embodiment not according to the invention, FIGS. 18 and 19 graphically show the measurement results for a component 1 having a photoactive layer 5 having a donor-acceptor system, wherein the photoactive layer 5 has a layer thickness of 30 nm. The deposition of the photoactive layer 5 took place at room temperature in FIG. 18 and at FIG. 19. FIG. 18 shows the current-voltage characteristics of a component 1 having a donor acceptor system and FIG. 19 shows a current-voltage characteristics for a component having a photoactive layer comprising the donor acceptor system and compound (VI). The photoactive layer 5 of the components differs here with regard to the admixture of the compound (VI) and the substrate temperature during the deposition of the photoactive layer 5.In a further exemplary embodiment, FIG. 20 shows an energy diagram of a component having a photoactive layer comprising a donor material, an acceptor material and a third material. In this case, FIG. 20 shows the HOMO layer of the donor material 10 and the LUMO layer of the donor material 11. Furthermore, FIG. 20 shows the HOMO layer of the acceptor 20 and the LUMO layer of the acceptor 21, Furthermore, FIG. 20 shows the HOMO layer of the third material 30 and the LUMO layer of the third material 31. As can be seen from FIG. 20, it has a HOMO layer 30 in terms of amount equal to or above that of the HOMO layer of the donor material and a LUMO layer 31 in terms of amount equal to or below the LUMO layer of the acceptor, that is to say between the LUMO layer of the acceptor and the vacuum level. The vacuum level of the energy is represented by reference numeral 40.List of reference characters1 Optoelectronic component 2 Substrate 3 Electrode 4 Charge carrier transport layer (ETL or HTL) 5 Photoactive layer 6 Charge carrier transport layer (ETL or HTL) 7 Counterelectrode 10 HOMO layer of the donor material 11 LUMO layer of the donor material 20 HOMO layer of the acceptor material 21 LUMO layer of the acceptor material 30 HOMO layer of the third material 31 LUMO layer of the third material 40 Vacuum level of the energy

Claims

Optoelectronic component (1) in the form of an organic solar cell comprising at least one photoactive layer (5) made of small molecules, non-polymeric organic molecules with monodisperse molar masses between 100 and 2000, which is arranged between an electrode (3) and a counter electrode (7), wherein the photoactive layer (5) comprises a multiple mixed layer containing at least a first material, a second material and a third material, wherein the first material is a donor made of organic material made of small molecules, wherein the second material is an acceptor from the group of fullerenes or fullerene derivatives, wherein the donor and the acceptor form a donor-acceptor system, and at least the one third material which is designed such that it influences the tendency of the donor and / or acceptor to crystallize, wherein the third material is a crown ether selected from a group of the general formula (Ia) or (Ib) with Ar=phenyl, biphenyl, triphenyl, naphthyl, binaphthyl, 3-6 annellated phenyl rings, anthracenyl, phenanthrenyl, pyrenyl, hetar=thiophene, pyrrole, furan, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyrimidine, pyrazine, benzothiophenes, benzopyrrole, benzofuran, benzothiophene, benzopyrrole, benzofuran, benzoxazole, Benzothiazol,Thienothiophene thienopyrrole, thienofuran, 3-6 annellated heterocycles, Dithienothiophene, dithienopyrrole, dithienobenzene, Dithienocyclopentadiene dipyrrolobenzene, ether bridges in 1,2-, 1,3- and 1,4-linkage on the respective phenyl ring (ortho, meta and para position), naphthyl ring, fused phenyl ring and heteroaryl ring and fused heteroaryl ring, m and n independently of one another are 3,4,5,6 for formula (Ia) and m and n independently of one another are 1,2,3,4,5,6 for formula (Ib), and o and p independently of one another are 0,1,2,3,4,5,6.Optoelectronic component according to claim 1, characterised in that the third material has an energy level at which the amount of LUMO is less than or equal to the amount of LUMO of the acceptor, and the amount of HOMO is greater than or equal to the amount of HOMO of the donor.Optoelectronic component according to either of Claims 1 and 2, characterized in that the third material has an energy level, wherein the amount of LUMO of the third material is less than the amount of LUMO of the acceptor material of the photoactive layer (5) by 0.3 eV and / or the amount of HOMO of the third material is greater than the amount of the energy level of HOMO of the donor material of the photoactive layer (5) by 0.3 eV.Optoelectronic component according to one of the preceding claims, characterized in that the proportion of the third material in the photoactive layer (5) is 0.1% by weight<x<30% by weight.Optoelectronic component according to one of the preceding claims, characterized in that at least one donor material of the photoactive layer (5) is an oligomer.Optoelectronic component according to one of the preceding claims, characterized in that the third material is formed such that the third material minimizes a crystallization of the donor and / or acceptor phase on account of its molecular structure.Optoelectronic component according to one of the preceding claims, characterized in that the molecular structure of the third material is formed such that the third material causes a lattice defect in the donor and / or acceptor material.Optoelectronic component according to one of the preceding claims, characterized in that the third material is selected such that the third material sets a minimum distance between the acceptor and donor, wherein the third material simultaneously contributes to the phase separation of the acceptor and donor.Optoelectronic component according to one of the preceding claims, characterized in that the third material is formed such that the third material promotes crystallization of the donor and / or acceptor phase on account of its molecular structure.Optoelectronic component according to one of the preceding claims, characterized in that the molecular structure of the third material has a first region which is formed to be fullereneophilic and a second region which is formed to be fullereneophilic, wherein the first and second regions are formed to be spatially separated.Optoelectronic component according to claim 10da, characterised in that the crown ethers are compounds of the following structures: or or or or or wherein in each case: n and m independently of one another are selected from 3, 4 or 5, and R 1, R 2, R 3, R 4, R5, R6, R7, R8, R9, R10, R 11 and R 12 independently of one another selected from H, CH 3, C 2 H 5, C 3 H 7, C 4 H 9, C 5 H11, C6H13, isobutyl, CF3, C2F5, C3F7, C4F9, C 5 F 11, C 6 F 13, OH, O-CH 3, CH 2- O-CH 3, CH 2- O-CH 2- CH 3, CN, phenyl, thiophene.Optoelectronic component according to claim 11 characterised in that the crown ethers have the following general formula (II): with Ar = phenyl, biphenyl, triphenyl, naphthyl, binaphthyl, 3-6 annellated phenyl rings (anthracenyl, phenanthrenyl, pyrenyl,...), hetar = thiophene, pyrrole, furan, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyrimidine, pyrazine, benzothiophenes, benzopyrrole, benzofuran, benzothiophene, benzopyrrole, benzofuran, benzoxazole, Benzothiazol,Thienothiophene thienopyrrole, thienofuran, 3-6 annellated heterocycles, Dithienothiophene, dithienopyrrole, dithienobenzene, Dithienocyclopentadiene dipyrrolobenzene, ether bridges in 1,2-, 1,3- and 1,4-linkage on the respective phenyl ring (ortho, meta and para position), naphthyl ring, fused phenyl ring and heteroaryl ring and fused heteroaryl ring, m and n independently of one another are 1,2,3,4,5,6, and p and q independently of one another are 1,2,3,4,5,6.Use of crown ethers according to any of Claims 1 to 12 in photoactive layers composed of small molecules, nonpolymeric organic molecules having monodisperse molar masses between 100 and 2000 organic solar cells.

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