Compounds containing a furopyrrole or a thienopyrrole group, optoelectronic devices containing such a compound, and the use of such a compound in optoelectronic devices

Abstract

Connection of the general formula I characterized by the fact that QO or S is preferred, QS is preferred; R1 is selected from the group consisting of alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; X1 and X2 are independently N or C-R4; wherein R4 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; A1 is a group with formula Ia, where * denotes the connection to the compound of the general formula I; Z1 is selected from the group consisting of O, S, Se, and N-R5. where R5 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y1 N or C-R6, where R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted in each case; Y2N or C-R7, where R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; and wherein R6 and R7 may be homocyclic or heterocyclic linked to each other in the form of a ring structure; R2 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group with at least one C=C double bond, where H may be substituted by CN or F; A2 is a group with the formula Ib, where * denotes the connection to the compound of the general formula I; Z2 is selected from the group consisting of O, S, Se, and N-R8, where R8 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y3N or C-R9, where R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted in each case; Y4N or C-R10, where R10 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; and wherein R9 and R10 may be homocyclic or heterocyclic linked to each other in the form of a ring structure; and R3 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group with at least one C=C double bond, where H may be substituted by CN or F.

Description

[0001] The present invention relates to compounds of the general formula I, optoelectronic components comprising such a compound, and the use of such a compound in optoelectronic components.

[0002] For optoelectronic components, interconnections made of electrically conductive polymers or small organic molecules are often used. Optoelectronic components can be, for example, displays, data storage devices, or transistors, but also organic optoelectronic components, especially organic photoactive components, such as solar cells and photodetectors, which have a photoactive layer in which charge carriers, particularly bound electron-hole pairs (excitons), are generated upon exposure to electromagnetic radiation.

[0003] Organic optoelectronic components enable the conversion of electromagnetic radiation into electrical current by utilizing the photoelectric effect. Such conversion of electromagnetic radiation requires absorber materials with good absorption properties. Other optoelectronic components are light-emitting electroluminescent components, which emit light when electrical current flows through them. Optoelectronic components comprise at least two electrodes, with one electrode applied to a substrate and the other acting as a counter electrode. Between the electrodes is at least one layer system, wherein the layer system comprises at least one organic photoactive layer. In addition, further layers, for example charge carrier transport layers, can be arranged between the electrodes.

[0004] A prior art organic solar cell structure consists of a pin or nip structure (Martin Pfeiffer, "Controlled doping of organic vacuum deposited dye layers: basics and applications," PhD thesis, TU Dresden, 1999, and WO2011 / 161108A1). A pin solar cell consists of a substrate with an adjoining, usually transparent, electrode, p-layer(s), i-layer(s), n-layer(s), and a counter electrode. A nip solar cell consists of a substrate with an adjoining, usually transparent, electrode, n-layer(s), i-layer(s), p-layer(s), and a counter electrode.

[0005] Numerous absorber materials for organic solar cells are known from the state of the art.

[0006] WO 2017 / 114 937 A1 discloses an organic compound characterized by high absorption in the short-wavelength spectral range of visible light. Furthermore, the use of this compound for an organic electronic component and a method for producing the compound are disclosed.

[0007] WO 2017 / 114 938 A1 discloses an organic semiconducting material and its use in organic components, wherein the organic material can serve as a functional component in organic electronic components and leads to improved absorption in organic solar cells or has increased charge carrier mobility.

[0008] WO 2015 / 024 848 A1 discloses ADA absorber materials with terminal heteroarylcyanovinyl groups and their use in organic solar cells.

[0009] Li et al. (J. Mater. Chem. A, 2018, 6, 18583-18591) disclose BODIPY compounds with CF3 groups in the meso position and with furopyrrole groups at the central C atom of the BODIPY compounds as donors in organic solar cells.

[0010] Li et al. (J. Am. Chem. Soc., 2017, 139, 13636-13639) disclose BODIPY compounds with CF3 groups in the meso position as donors in organic tandem solar cells.

[0011] WO 2014 / 128277 A1 discloses compounds of the general formula ADA' with an asymmetric donor block D, and their use in optoelectronic components.

[0012] Although the absorber materials disclosed in the prior art are suitable for photoactive layers in organic photovoltaic elements, i.e., organic solar cells, the absorption properties of the absorber materials need to be improved, particularly to make organic photovoltaic elements (OPVs) competitive with conventional silicon-based solar cells. The efficiency of an organic photovoltaic element depends, among other things, on the absorption behavior of the organic compounds, i.e., the absorber materials, in the at least one photoactive layer.Particularly in tandem, triple, or multiple cells, high overall absorption and absorption across a broad range of the available electromagnetic radiation spectrum are advantageous due to multiple absorber materials that absorb in different wavelength ranges, as this allows photons of different wavelengths to be used to generate electrical current. The individual cells of the tandem, triple, or multiple cells should have an open-circuit voltage of the same order of magnitude, particularly in the range of 0.9 to 1.1 V.

[0013] A particular disadvantage of the prior art is the absorption properties of absorber materials in the blue / green range of visible light, whereby high absorption coefficients are required for the construction of solar cells with open-circuit voltages Uoc in the range of 0.9 V to 1.1 V. At wavelengths in the range of 500 nm - 600 nm, the absorption of known organic compounds suitable for organic photovoltaic elements is insufficient. This is particularly disadvantageous when constructing tandem, triple, and multiple cells, since the individual sub-cells do not exhibit the same order of magnitude in terms of efficiency and open-circuit voltage. Thus, one sub-cell delivers a lower open-circuit voltage than another, resulting in a sub-cell making only a smaller contribution to the efficiency of the component.

[0014] The invention is therefore based on the object of providing organic compounds for use in organic optoelectronic components, an optoelectronic component comprising at least one such compound, and the use of such compounds in an optoelectronic component, wherein the aforementioned disadvantages do not occur and wherein the organic compounds in particular exhibit improved absorption properties.

[0015] The problem is solved by the subject matter of the independent claims. Advantageous embodiments emerge from the subclaims.

[0016] The object is achieved in particular by providing a compound of the general formula I, characterized in that QO or S, preferably QS; R1 is selected from the group consisting of alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; X1 and X2 are independently N or C-R4; where R4 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; A1 is a group with the formula Ia, where * denotes the linkage to the compound of general formula I; Z1 is selected from the group consisting of O, S, Se, and N-R5, where R5 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y1 is N or C-R6, wherein R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; Y2 is N or C-R7, where R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R6 and R7 may be homocyclic or heterocyclic to each other in the form of a ring structure; R2 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; A2 a group with the formula Ibis, where * denotes the linkage to the compound of general formula I; Z2 is selected from the group consisting of O, S, Se, and N-R8, where R8 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y3 is N or C-R9, where R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; Y4 is N or C-R10, where R10 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R9 and R10 may be homocyclic or heterocyclic to each other in the form of a ring structure; and R3 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F.

[0017] The present invention relates in particular to ADA dyes of the compound of general formula I having a central furopyrrole unit or a central thienopyrrole unit.

[0018] In a preferred embodiment of the invention, X1 and X2 are H.

[0019] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is a furan or a furan derivative.

[0020] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is a thiophene or a thiophene derivative.

[0021] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is a pyrrole or a pyrrole derivative.

[0022] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is a thiazole or a thiazole derivative.

[0023] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is a thiadiazole or a thiadiazole derivative.

[0024] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is an oxazole or an oxazole derivative.

[0025] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is an imidazole or an imidazole derivative.

[0026] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is a triazole or a triazole derivative.

[0027] In a preferred embodiment of the invention, the group of formula Ia and / or the group of formula Ib is an oxadiazole or an oxadiazole derivative.

[0028] In a preferred embodiment of the invention, at least two of the groups A1, A2, A3 or A4 are a furan, a thiophene, a pyrrole, a thiazole, a thiadiazole, an oxazole, an imidazole, a triazole, or an oxadiazole, or a derivative thereof.

[0029] In the context of the present invention, a derivative is understood to mean in particular a compound or residue derived from a basic structure, wherein individual atoms or groups are modified or substituted starting from the original compound.

[0030] In a preferred embodiment of the invention, a furan and / or a thiophene group, in particular a furan group, is arranged on the furopyrrole unit or on the thienopyrrole unit, in particular on the thienopyrrole unit, and a sterically demanding group, in particular isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, or phenyl, is arranged on the N of the pyrrole of the furopyrrole unit or the thienopyrrole unit. This improves the properties of the absorber materials in a particularly significant way.

[0031] In a preferred embodiment of the invention, the central furopyrrole unit or the central thienopyrrole unit, in particular the pyrrole ring of the thienopyrrole unit, does not have any further condensed aromatic system.

[0032] In a preferred embodiment of the invention, R5 and R6 are H.

[0033] In an alternatively preferred embodiment of the invention, the compound of general formula I has a homocyclic five-membered ring or six-membered ring formed together by R5 and R6 and / or R9 and R10, or a heterocyclic five-membered ring or six-membered ring with at least one heteroatom selected from the group consisting of S, O and N, where the five-membered ring or the six-membered ring may be substituted at further positions.

[0034] An absorber material, i.e., an absorber, is understood in particular to be a compound that absorbs light in the wavelength range >400 nm. Accordingly, an absorber layer is understood in particular to be a layer in an optoelectronic component that comprises at least one absorber material.

[0035] A steep absorption spectrum, especially a steep absorption spectrum in the bathochromic region, is understood to mean a steepness at an inflection point of the absorption spectrum. The steepness of the absorption spectrum is determined by the slope of the tangent at the inflection point, which lies between the beginning of absorption and the first absorption edge (Wang et al., "Optical Gaps of Organic Solar Cells as a Reference for Comparing Voltage Losses," Adv. Energy Mater., 2018, 1801352). Fig. 7.

[0036] In a preferred embodiment of the invention, compounds according to the invention have an absorption spectrum slope of at least 5.6, preferably of at least 5.8, preferably of at least 6, preferably of at least 6.5, preferably of at least 7, preferably of at least 7.5, or preferably of at least 8.

[0037] Substitution is understood, in particular, to mean the replacement of H by a substituent. A substituent is understood, in particular, to mean all atoms and atom groups other than H, preferably a halogen, an alkyl group (the alkyl group may be linear or branched), an amino group, a CN group, an alkenyl group, an alkynyl group, an alkoxy group, a thioalkoxy group, an aryl group, or a heteroaryl group. A halogen is understood, in particular, to mean F, Cl, or Br, preferably F.

[0038] A heteroatom, in particular a heteroatom, is understood to mean in particular an atom selected from the group consisting of O, S, Se, Si, B, N or P, preferably selected from the group consisting of O, S, Se or N, particularly preferably O or S.

[0039] In a preferred embodiment of the invention, no C of an alkyl group is replaced by a heteroatom.

[0040] The compounds according to the invention relate in particular to so-called small molecules. Small molecules are understood to be, in particular, non-polymeric organic molecules with monodisperse molar masses between 100 and 2000 g / mol, which exist in the solid phase under normal pressure (the atmospheric pressure of the surrounding atmosphere) and at room temperature. In particular, the small molecules are photoactive, whereby photoactive means that the molecules change their charge state and / or polarization state upon exposure to light. The photoactive molecules exhibit, in particular, an absorption of electromagnetic radiation in a specific wavelength range, whereby absorbed electromagnetic radiation, i.e., photons, are converted into excitons.

[0041] The compounds of the invention exhibit, in particular, a high absorption coefficient at least in a specific wavelength range. The compounds of the invention are used, in particular, in a donor-acceptor system with heterojunction.

[0042] In a preferred embodiment of the invention, Y1, Y2, Y3, and Y4 are each independently selected from the group consisting of N, CH, CF, C-CH3, C-CF3, C-C2H5, C-C3H8, C-OCH3, C-OC2H5, C-SCH3, C-SC2H5.

[0043] In a preferred embodiment of the invention, the cyclic or linear alkyl groups of the compounds according to the invention are linear or branched, preferably the alkyl groups are linear C1-C5 alkyl groups.

[0044] In a preferred embodiment of the invention, at least one of the positions Y1, Y2, Y3 and Y4 is an N, preferably at least one of the positions Y1 and Y2 is an N, and at least one of the positions Y3 and Y4 is an N. In a particularly preferred embodiment of the invention, the positions Y1, Y2, Y3 and Y4 are each an N.

[0045] In a preferred embodiment of the invention, positions Y1, Y2, Y3, and Y4 are each CH.

[0046] In a preferred embodiment of the invention, the compound of general formula I has an O at position Z1 of formula Ia and an O at position Z2 of formula Ib. As a result, the absorption properties are particularly favorable than those of comparable compounds with a different atom at these positions.

[0047] The compounds according to the invention have advantages over the prior art. Advantageously, the compounds according to the invention exhibit surprisingly good absorption behavior in a comparatively broad spectral range of visible light; in particular, a surprisingly high absorption was observed in the spectral range from approximately 500 nm to 600 nm. Advantageously, absorber materials with improved absorption in a wavelength range of the blue / green region of visible light are provided. Advantageously, compounds according to the invention exhibit a particularly steep absorption curve in the bathochromic range.Advantageously, the compounds of the invention possess sufficient thermal, chemical, and electrochemical stability to meet the requirements typically imposed on them during the manufacture and operation of photoactive organic electronic components; in particular, these compounds are readily evaporable in a vacuum. Advantageously, the compounds of the invention enable the construction of solar cells with an open-circuit voltage Uoc in the range of 0.9 to 1.1 V, in particular in the range of 0.95 V to 1.05 V.

[0048] According to a further development of the invention, R1 is selected from the group consisting of ethyl, propyl, butyl, branched alkyl, and aryl, preferably from isopropyl, isobutyl, sec-butyl, isopentyl, tert-butyl, and phenyl; and wherein Z1 and Z2 are each independently O or S.

[0049] In a particularly preferred embodiment, Z2 is O. This realizes the advantageous effects of the present invention in a special way.

[0050] According to a further development of the invention, the compound is a compound of the general formula II, where n is 0, 1 or 2 and m is 0, 1 or 2; Q is O or S, preferably Q is S; Z3 and Z4 are each independently selected from the group consisting of O, S, Se, and N-R11, where R11 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; Y5 is N or C-R14, wherein R14 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, each of which H may be substituted, with Y5 preferably being N, CH or CF; Y6 is N or C-R15, wherein R15 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, each of which H may be substituted, with Y6 preferably being N, CH or CF; Y7 is N or C-R16, wherein R16 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, each of which H may be substituted, with Y7 preferably being N, CH or CF; Y8 is N or C-R17, where R17 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted, where Y8 is preferably N, CH or CF; and wherein R14 and R15, and / or R16 and R17 together may form a homocyclic five-membered ring or six-membered ring, or a heterocyclic five-membered ring or six-membered ring having at least one heteroatom selected from the group consisting of S, O and N.

[0051] In a preferred embodiment of the invention, Z3 and Z4 are independently O or S.

[0052] In a preferred embodiment of the invention, the compound of general formula II has an O at position Z1 and an O at position Z2, and an O at position Z3 and / or an O at position Z4.

[0053] According to a further development of the invention, A1 is a group with the formula IIa, wherein R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R6 and R7 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; and A2 is a group of the formula IIb, where R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; R10 is selected from the group consisting of H, halogen, Alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may each be substituted; and where R9 and R10 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N.

[0054] In a particularly preferred embodiment of the invention, the compound is a compound of the general formula XIX characterized in that A1 is a group with the formula Ia, where * denotes the linkage to the compound of general formula I; Z1 is selected from the group consisting of O, S, Se, and N-R5, where R5 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y1 is N or C-R6, wherein R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; Y2 is N or C-R7, where R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R6 and R7 may be homocyclic or heterocyclic to each other in the form of a ring structure; R2 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F.

[0055] In a preferred embodiment of the invention, positions Y1 and Y2 of the compound of general formula XIX are each CH.

[0056] In a preferred embodiment of the invention, the compound of general formula XIX has an O at position Z1 of formula Ia.

[0057] In a preferred embodiment of the invention, at least one of the positions Y1 or Y2 of the compound of general formula XIX is an N, preferably the positions Y1 and Y2 are an N.

[0058] According to a further development of the invention, the compound is a compound of the general formula III, IV and / or V, where Q is O or S, preferably QS; Z1 and Z2 are each independently O or S, preferably Z2 is O; R6 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R7 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R6 and R7 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; R9 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R10 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R9 and R10 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; and R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F.

[0059] In a preferred embodiment of the invention, the compound is a compound selected from the general formulas and where Q is O or S, preferably QS; Z1 and Z2 are each independently O or S, preferably Z2 is O; R6 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R7 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R6 and R7 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; R9 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R10 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R9 and R10 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; and R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F.

[0060] In a preferred embodiment of the invention, the compound is a compound of general formula VII and VIII, where Z1 and Z2 are each independently O or S, R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; and R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F.

[0061] According to a further development of the invention, it is provided that R2 and R3, or R12 and R13 are each independent of each other, where n is 1, 2 or 3, where * denotes the attachment of the group R2, R3, R12 and / or R13; R16, R17, and R18 are each independently selected from the group consisting of H, halogen, CN, COO-alkyl, alkyl, and alkenyl, with the proviso that R16 and R17 are not both H, with R16 and R17 preferably being CN. This realizes the advantageous effects of the present invention in a special way.

[0062] In a preferred embodiment of the invention, R2 and / or R3, or R12 and / or R13 are each independently where m is 0, 1 or 2, and l is 0, 1 or 2; where * denotes the attachment of the group R2, R3, R12 and / or R13; R21, R22, R23, R24, R25, and R26 are each independently selected from the group consisting of H, halogen, CN, COO-alkyl, and alkenyl, with the proviso that R21 and R22 are not both H, with R21 and R22 preferably being CN. A particularly good acceptor effect of the groups R2 and / or R3, or R12 and / or R13, can preferably be achieved by a large number of CN groups.

[0063] According to a further development of the invention, it is provided that R2 and R3, or R12 and R13 are each independently selected from the group consisting of: where * denotes the attachment of the group R2, R3, R12 and / or R13, where CN may be replaced by F, and where preferably R2 and R3, or R12 and R13 are the same.

[0064] According to a further development of the invention, R6 and R7 are H, R9 and R10 are H, and Z2 is O; preferably, Z1 and Z2 are O. This realizes the advantageous effects of the present invention in a special way.

[0065] In a preferred embodiment of the invention, R4 is H, R6 and R7 are H and / or R9 and R10 are H, and Z1 and Z2 are O.

[0066] According to a further development of the invention, the compound is selected from the group consisting of:

[0067] In a preferred embodiment of the invention, R2 and / or R3, or R12 and / or R13 have at least two C=C double bonds.

[0068] According to a further development of the invention, it is provided that group A1 is equal to group A2.

[0069] In a particularly preferred embodiment of the invention, the compound is compound F3. Here, the advantageous absorption properties are realized to a particularly high degree.

[0070] In a particularly preferred embodiment of the invention, the compound is compound F6. In this case, the advantageous absorption properties are realized to a particularly high degree.

[0071] In a particularly preferred embodiment of the invention, the compound is compound F12. Here, the advantageous absorption properties are realized to a particularly high degree.

[0072] Organic single-cell or tandem cells are known from the prior art. DE 10 2004 014 046 A1 discloses a photoactive component, in particular a solar cell, consisting of organic layers of one or more stacked pi, ni, and / or pin diodes. WO 2011 / 161 108 A1 discloses a photoactive component with an electrode and a counterelectrode, with at least one organic layer system arranged between the electrodes, with at least two photoactive layer systems and at least two different transport layer systems of the same charge carrier type between the photoactive layer systems. One transport layer system is energetically matched to one of the two photoactive layer systems, and the other transport layer system is transparent.

[0073] The object of the present invention is also achieved by providing an optoelectronic component with at least one compound according to the invention, in particular according to one of the previously described embodiments. This results in particular in the advantages for the optoelectronic component that have already been explained in connection with the compound according to the invention. The optoelectronic component comprises a first electrode, a second electrode, and a layer system, wherein the layer system is arranged between the first electrode and the second electrode, characterized in that at least one layer of the layer system comprises at least one compound according to the invention.

[0074] An organic optoelectronic component is understood to mean, in particular, a component comprising organic conductive or semiconducting materials, in particular a transistor, a light-emitting organic component, an organic photovoltaic element (OPV), in particular an organic solar cell, or a photodetector. Organic photovoltaic cells comprising at least one compound according to the invention enable particularly efficient use of the visible light spectrum.

[0075] An organic photovoltaic element (OPV) is understood to mean, in particular, a photovoltaic element, in particular a solar cell, with at least one organic photoactive layer, wherein the organic photoactive layer comprises at least one compound according to the invention. An organic photovoltaic element enables electromagnetic radiation, in particular in the wavelength range of visible light, to be converted into electrical current by utilizing the photoelectric effect.

[0076] According to a further development of the invention, it is provided that the optoelectronic component is an organic optoelectronic component, preferably an organic solar cell, an OFET, an OLED or an organic photodetector.

[0077] According to a further development of the invention, it is provided that the layer system has at least one photoactive layer, preferably an absorber layer, wherein the at least one photoactive layer has the at least one compound according to the invention.

[0078] The organic electronic component comprises, in particular, an electrode and a counterelectrode, with an organic photoactive layer arranged between the electrodes. The organic photoactive layer is, in particular, a photoactive layer in which excitons (electron-hole pairs) are formed by exposure to visible light, UV radiation, and / or IR radiation. The organic materials are printed, glued, coated, vapor-deposited, or otherwise applied to the films in the form of thin films or small volumes. All processes used for electronics on glass, ceramic, or semiconducting substrates can also be used to produce the thin layers.The organic photoactive layer has an important function for the optoelectronic component, in particular a charge carrier transporting function, such as the transport of holes (p-conducting) or the transport of electrons (n-conducting).

[0079] According to a further development of the invention, the layer system comprises at least two photoactive layers, preferably at least three photoactive layers, or preferably at least four photoactive layers, wherein the photoactive layers are preferably absorber layers. In a preferred embodiment of the invention, the at least one photoactive layer is arranged between the first electrode and the second electrode.

[0080] In a preferred embodiment of the invention, the organic solar cell has a photoactive layer comprising at least one organic donor material in contact with at least one organic acceptor material, wherein the donor material and the acceptor material form a donor-acceptor heterojunction, in particular a so-called bulk heterojunction (BHJ), and wherein the photoactive layer comprises at least one compound according to the invention.

[0081] In a preferred embodiment of the invention, the optoelectronic component has at least one further layer, preferably at least one charge transport layer, in particular an electron transport layer and / or a hole transport layer.

[0082] In a preferred embodiment of the invention, the at least one charge transport layer, in particular at least one electron transport layer and / or at least one hole transport layer, comprises the at least one compound according to the invention.

[0083] In a preferred embodiment of the invention, the optoelectronic component comprises a substrate, wherein the first electrode or the second electrode is arranged on the substrate, in particular one of the electrodes of the optoelectronic component can be applied directly to the substrate, and wherein the layer system is arranged between the first electrode and the second electrode.

[0084] In a preferred embodiment of the invention, the organic solar cell is a single cell, a tandem cell, a triple cell, a quadruple cell or another multiple cell.

[0085] A tandem cell is understood in particular to mean that two functional cells are spatially stacked one above the other and connected in series, preferably between a first electrode and a second electrode, wherein one or more intermediate layers can be arranged between the cells. A triple, quadruple, or other multiple cell is understood accordingly to mean that more than two functional cells are spatially stacked one above the other and connected in series, wherein an intermediate layer can be arranged between the cells.

[0086] According to a further development of the invention, it is provided that the photoactive layer is formed as a mixed layer of the at least one compound according to the invention and at least one further compound, or as a mixed layer of the at least one compound according to the invention and at least two further compounds, wherein the compounds are absorber materials.

[0087] In a preferred embodiment of the invention, the optoelectronic component is designed as a nip, ni, ip, pnip, pni, pip, nipn, nin, ipn, pnipn, or pipn cell, or as a combination of nip, ni, ip, pnip, pni, pip, nipn, nin, ipn, pnipn, or pipn cells.

[0088] In a particularly preferred embodiment of the invention, the optoelectronic component is designed as a mip cell, or as a combination of a mip cell with a nip, ni, ip, pnip, pni, pip, nipn, nin, ipn, pnipn, or pipn cell.

[0089] An i-layer is specifically understood to be an intrinsic undoped layer. One or more i-layers can consist of a single material (planar heterojunctions, PHJ) or a mixture of two or more materials (bulk heterojunctions, BHJ) that exhibit an interpenetrating network.

[0090] In a preferred embodiment, the compound according to the invention and / or a layer comprising the at least one compound according to the invention can be deposited by means of vacuum processing, gas phase deposition or solvent processing, particularly preferably by means of vacuum processing.

[0091] The object of the present invention is also achieved by providing the use of a compound according to the invention in an optoelectronic component, preferably an organic optoelectronic component, in particular according to one of the previously described embodiments. The use of the compound according to the invention in an optoelectronic component results in particular in the advantages already explained in connection with the compound according to the invention and the optoelectronic component comprising the at least one compound according to the invention.

[0092] In a preferred embodiment of the invention, the optoelectronic component is an organic optoelectronic component, preferably an organic solar cell.

[0093] In the following, some examples of compounds according to the invention and non-inventive compounds (F1 and F2) are shown with their optical properties. Table 1 shows an overview of the melting points and absorption maxima (in nm and eV in the solvent (solvent)) of these compounds. The spectral data refer to 30 nm thick vacuum deposition layers on quartz glass. The corresponding absorption spectra of the compounds F3 and F12 listed in Table 1 are shown in the Fig. 3 and Fig. 4 and a comparison with the reference compound F1 in Fig. 5 shown. Table 1 Nr. Struktur Smp. / ° C a λmax (LM) / nm b λmax (LM) / eV b F1 ca. 370°C 562 c 2,21 c F2 349 555 b 2,23 b F3 356 569 b 2,18 b F4 330 543 b 2, 28 b F5 343 540 c 2.30 c F6 nd 558 c 2,22 c F7 nd F8 nd F9 nd F10 325 597 b 2,08 b F11 314 534 b 2,32 b F12 291 555 b 2,23 b a onset DSC (differential scanning calorimetry) b in Dichlormethan

[0094] The optical properties were determined experimentally. The absorption maxima λmax were determined using a diluted solution in a cuvette in dichloromethane using a photometer. The measured absorption maxima of all described compounds lie in the range of 534 to 597 nm.

[0095] Table 2 shows various parameters of the inventive compounds F3, F6, and F12 and the comparison compound F1. The parameters open-circuit voltage Uoc, short-circuit current Jsc, and fill factor FF each refer to the same solar cell structure.

[0096] To investigate the compounds, i.e. their use as absorber materials in organic optoelectronic components, the current-voltage curve was measured in a BHJ cell with the structure: glass with ITO / C60 (15 nm) / absorber material: C60 (30 nm, 3:2, 50°C) / BPAPF (10 nm) / BPAPF: NDP9 (30 nm, 10%wt NDP9) / NDP9 (1 nm) / Al (100 nm) under AM1.5 illumination (AM = Air Mass; AM = 1.5 in this spectrum the global radiant power is 1000 W / m 2(AM = 1.5 as the standard value for measuring solar modules), with the photoactive layer being a bulk heterojunction (BHJ). A transparent cover contact made of ITO (indium tin oxide) is applied to a glass substrate. ITO serves as the electrode, and the adjacent fullerene C60 as the electron transport layer (ETL). This is followed by the photoactive layer C60 as the electron acceptor material and the respective compound, followed by BPAPF (9,9-bis[4-(N,N-bis-biphenyl-4-yl-amino)phenyl]-9H-fluorene) as the hole transport layer (HTL) and BPAPF doped with NDP9 (Novaled AG), followed by an aluminum electrode.

[0097] The advantageous technical effect of compounds according to the invention which have a central thienopyrrole unit or a central furopyrrole unit, in particular a central thienopyrrole unit, in interaction with a furan group or a thiophene group, in particular a furan group, on the pyrrole of the central thienopyrrole unit or the central furopyrrole unit, and which have a sterically demanding group on the N of the pyrrole of the central thienopyrrole unit or the central furopyrrole unit, is shown below in Table 2 by way of example using compounds F3, F6 and F12 compared to a comparison compound F1. The experimental data of compounds F3 and F12 are shown in Fig. 3 and Fig. 4 shown. Table 2 Substanz Steilheit Uoc [V] Jsc / EQE [mA / cm 2 ] FF [%] 2,75 0,81 7,5 47, 0 9,72 0,91 15,1 68, 9 5,76 5, 9 0,97 10,3 46,6

[0098] The particularly advantageous properties of the compounds according to the invention are also evident in the open-circuit voltage Uoc, short-circuit current Jsc, and fill factor FF for identical solar cell structures. The compounds according to the invention exhibit not only improved absorption properties but also suitable charge transport properties. Depending on the charge transport properties and the absorption properties, high photocurrents with good fill factors can be achieved. This allows for the production of particularly good combinations of photoactive layers, particularly for tandem, triple, quadruple, or multi-junction solar cells.

[0099] In a particularly preferred embodiment, the compounds according to the invention have a central thienopyrrole unit with a furan ring on the pyrrole of the central thienopyrrole unit together with a sterically demanding group on the N of the pyrrole ring of the central thienopyrrole unit; compounds F3 and F6 are shown as examples in Table 2.

[0100] The invention is explained in more detail below with reference to the drawings. In the drawings: Fig. 1 shows an embodiment of a synthesis scheme for the synthesis of compounds according to the invention; Fig. 2 a schematic representation of an embodiment of an optoelectronic component in cross section; Fig. 3 a graphical representation of the absorption spectrum of compound F3, and the current-voltage curve, the spectral external quantum efficiency and the fill factor of a BHJ cell with compound F3, measured on an organic optoelectronic device in the form of an organic solar cell; Fig. 4 a graphical representation of the absorption spectrum of compound F12, and the current-voltage curve, the spectral external quantum efficiency and the fill factor of a BHJ cell with compound F12, measured on an organic optoelectronic device in the form of an organic solar cell; Fig. 5 a graphical representation of the absorption spectrum of comparison compound F1, and the current-voltage curve, the spectral external quantum efficiency and the fill factor of a BHJ cell with comparison compound F1, measured on an organic optoelectronic device in the form of an organic solar cell; and Fig. 6 a graphical representation of a comparison of the absorption spectrum of compound F3 with a reference compound F1. Examples of implementation

[0101] Fig. 1 shows an embodiment of a synthesis scheme for the synthesis of compounds according to the invention.

[0102] The preparation of the compound according to the invention is known to the person skilled in the art from the prior art. In this context, particular reference is made to international patent applications WO 2017 / 114 937 A1 and WO 2017 / 114 938 A1. The compounds according to the invention are thus readily accessible and obtainable in good yields. A general synthesis for preparing a compound according to the invention is presented below as an example.

[0103] The compound of the general formula I according to the invention is characterized by the fact that QO or S, preferably QS; R1 is selected from the group consisting of alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; X1 and X2 are independently N or C-R4; where R4 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; A1 is a group with the formula Ia, where * denotes the linkage to the compound of general formula I; Z1 is selected from the group consisting of O, S, Se, and N-R5, where R5 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y1 is N or C-R6, where R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may in each case be substituted; Y2 is N or C-R7, where R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may in each case be substituted; and where R6 and R7 may be linked to one another homocyclically or heterocyclically in the form of a ring structure;R2 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; A2 is a group of formula Ib; where * denotes the linkage to the compound of general formula I; Z2 is selected from the group consisting of O, S, Se, and N-R8, where R8 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y3 is N or C-R9, where R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may in each case be substituted; Y4 is N or C-R10, where R10 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may in each case be substituted; and where R9 and R10 may be linked to one another homocyclically or heterocyclically in the form of a ring structure;and R3 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F;

[0104] Improved absorption properties, particularly steep absorption in the bathochromic range, combined with excellent charge transport properties, enable high photocurrents to be generated. This allows for the production of tandem, triple, quadruple, or multiple cells.

[0105] In one embodiment of the invention, R1 is selected from the group consisting of ethyl, propyl, butyl, branched alkyl, and aryl, preferably from isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, and phenyl; and wherein Z1 and Z2 are each independently O or S, preferably Z2 is O. The advantageous effects of the present invention are thereby realized in a special way.

[0106] In a further embodiment of the invention, the compound is a compound of the general formula II, where n is 0, 1 or 2 and m is 0, 1 or 2; Q is O or S, preferably Q is S; Z3 and Z4 are each independently selected from the group consisting of O, S, Se, and N-R11, where R11 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; Y5 is N or C-R14, wherein R14 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, each of which H may be substituted, with Y5 preferably being N, CH or CF;Y6 is N or C-R15, where R15 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may in each case be substituted, where Y6 is preferably N, CH or CF; Y7 is N or C-R16, where R16 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may in each case be substituted, where Y7 is preferably N, CH or CF; Y8 is N or C-R17, where R17 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may in each case be substituted, where Y8 is preferably N, CH or CF; and wherein each of R14 and R15, and / or R16 and R17 together may form a homocyclic five-membered ring or six-membered ring, or a heterocyclic five-membered ring or six-membered ring having at least one heteroatom selected from the group consisting of S, O and N;

[0107] In a further embodiment of the invention, R14 and R15 together and / or R16 and R17 together form a homocyclic five-membered ring or six-membered ring or a heterocyclic five-membered ring or six-membered ring with at least one heteroatom selected from the group consisting of S, O and N.

[0108] In a further embodiment of the invention, Z3 and Z4 are independently O or S.

[0109] In a further embodiment of the invention, A1 is a group with the formula IIa wherein R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R6 and R7 together form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; and A2 is a group with formula IIb, wherein R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; R10 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R9 and R10 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N.

[0110] In a further embodiment of the invention, the compound is a compound of the general formula III, IV and / or V, where Q is O or S, preferably Q is S; Z1 and Z2 are each independently O or S, preferably Z2 is O; R6 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted;

[0111] R7 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R6 and R7 together can form a homocyclic five-membered ring or six-membered ring, or a heterocyclic five-membered ring or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; R9 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R10 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R9 and R10 together can form a homocyclic five-membered ring or six-membered ring, or a heterocyclic five-membered ring or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N;R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; and R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F.;

[0112] In a further embodiment of the invention, R2 and R3, or R12 and R13 are each independently where n is 1, 2 or 3, where * denotes the attachment of the group R2, R3, R12 and / or R13; R16, R17 and R18 are each independently selected from the group consisting of H, halogen, CN, COO-alkyl, alkyl and alkenyl, with the proviso that R16 and R17 are not both H, preferably R16 and R17 are CN.

[0113] In a further embodiment of the invention, R2 and R3, or R12 and R13 are each independently selected from the group consisting of: where * denotes the attachment of the group R2, R3, R12 and / or R13, where CN may be replaced by F, and where preferably R2 and R3, or R12 and R13 are the same.

[0114] In a further embodiment of the invention, R6 and R7 are H, R9 and R10 are H, and Z2 is O, with Z1 and Z2 preferably being O.

[0115] In a further embodiment of the invention, the compound is selected from the group consisting of:

[0116] In a further embodiment of the invention, group A1 is equal to group A2.

[0117] Fig. 2 shows a schematic representation of an embodiment of an optoelectronic component in cross section.

[0118] The optoelectronic component comprises a first electrode 2, a second electrode 6, and a layer system 7, wherein the layer system 7 is arranged between the first electrode 2 and the second electrode 6. At least one layer of the layer system 7 comprises at least one compound according to the invention.

[0119] In one embodiment of the invention, the optoelectronic component is an organic optoelectronic component, preferably an organic solar cell, an OFET, an OLED or an organic photodetector.

[0120] In this embodiment, the optoelectronic component is an organic solar cell. The organic solar cell comprises a substrate 1, e.g., made of glass, on which an electrode 2, comprising, e.g., ITO, is located. Arranged thereon is a layer system 7 with an electron-transporting layer 3 (ETL) and a photoactive layer 4 with at least one compound according to the invention, a p-conducting donor material, and an n-conducting acceptor material, e.g., C60 fullerene, either as a shallow heterojunction or as a bulk heterojunction. Arranged above this is a p-doped hole-transporting layer 5 (HTL) and an electrode 6 made of aluminum.

[0121] In a further embodiment of the invention, the layer system 7 has at least one photoactive layer 4, preferably an absorber layer, wherein the at least one photoactive layer 4 has the at least one compound according to the invention.

[0122] In a further embodiment of the invention, the layer system 7 has at least two photoactive layers, preferably at least three photoactive layers, or preferably at least four photoactive layers.

[0123] In a further embodiment of the invention, the photoactive layer 4 is formed as a mixed layer of the at least one compound according to the invention and at least one further compound, or as a mixed layer of the at least one compound according to the invention and at least two further compounds, wherein the compounds are absorber materials.

[0124] In a further embodiment of the invention, the optoelectronic component is designed as a tandem cell, triple cell or multiple cell.

[0125] In the following Fig. 3 and Fig. 4 shows concrete embodiments of the compounds according to the invention and their optical properties.

[0126] Fig. Figure 3 shows a graphical representation of the absorption spectrum of compound F3 ( Fig. 3A), and the current-voltage curve, the spectral external quantum efficiency and the fill factor of a BHJ cell with compound F3 ( Fig. 3B), measured on an organic optoelectronic component in the form of an organic solar cell.

[0127] The absorption spectra (optical density versus wavelength in nm) were measured for 30 nm thick vacuum-deposited layers of compounds F3, F12, and the reference compound F1, each on quartz glass. The current-voltage curve contains parameters that characterize the organic solar cell. The most important parameters are the fill factor FF, the open-circuit voltage Uoc, and the short-circuit current Jsc.

[0128] The absorption spectrum of compound F3 is in Fig. 3A. Compound F3 exhibits a particularly steep absorption curve in the bathochromic region, i.e., at the flank in the higher wavelength range of the absorption spectrum, with a steepness of 9.72. The steepness of the absorption spectrum is determined by the slope of the tangent at the inflection point, which lies between the onset of absorption and the first edge of absorption. The bathochromic region is understood, in particular, to be a region shifted into the red wavelength range of visible light, i.e., into the longer-wavelength, lower-energy region of the electromagnetic spectrum. This steep curve in the bathochromic region of the absorption spectrum is particularly advantageous in the formation of tandem, triple, or multiple cells.

[0129] In this exemplary embodiment, the BHJ cell has a layer of C60 with a layer thickness of 15 nm on the ITO layer. Compound F3 was applied to this layer together with C60 in a thickness of 30 nm. This layer is followed by a layer of BPAPF (9,9-bis[4-(N,N-bis-biphenyl-4-yl-amino)phenyl]-9H-fluorene) with a layer thickness of 10 nm, followed by another layer comprising BPAPF and NDP9 with a layer thickness of 30 nm. The proportion of BPAPF in this layer is 10 weight percent, based on the entire layer. This layer is followed by another layer containing NDP9 with a thickness of 1 nm, followed by an aluminum layer with a thickness of 100 nm. The current-voltage curve of a BHJ cell with the structure: ITO / C60 (15 nm) / F3:C60 (30 nm, 3:2, 50°C) / BPAPF (10 nm) / BPAPF:NDP9 (30 nm, 10%wt NDP9) / NDP9 (1 nm) / Al (100 nm) was determined, where the photoactive layer is a bulk heterojunction (BHJ).In the optoelectronic component with connection F3, the fill factor FF is 68.9%, the open-circuit voltage Uoc is 0.91 V and the short-circuit current Jsc is 15.1 mA / cm2 (. Fig. 3B). The cell efficiency of such an optoelectronic component, in particular a solar cell, with compound F3 is 9.4%.

[0130] Compound F3 also shows good evaporability in vacuum.

[0131] Fig. Figure 4 shows a graphical representation of the absorption spectrum of compound F12 ( Fig. 4A), and the current-voltage curve, the spectral external quantum efficiency and the fill factor of a BHJ cell with the compound F12 ( Fig. 4B), measured on an organic optoelectronic component in the form of an organic solar cell.

[0132] The absorption spectrum of compound F12 is in Fig. 4A. Compound F12, like compound F3 before it, shows a particularly steep absorption curve with a slope of 5.9.

[0133] The current-voltage curve of a BHJ cell with the following structure: ITO / C60 (15 nm) / F12:C60 (30 nm, 3:2, 50°C) / BPAPF (10 nm) / BPAPF:NDP9 (30 nm, 10% wt NDP9) / NDP9 (1 nm) / Al (100 nm) was determined, with the photoactive layer being a bulk heterojunction (BHJ). In the optoelectronic component with F12 compound, the fill factor FF is 46.6%, the open-circuit voltage Uoc is 0.97 V, and the short-circuit current Jsc is 10.3 mA / cm2 ( Fig. 4B). The cell efficiency of such an optoelectronic component, in particular a solar cell, with the compound F12 is 4.7%.

[0134] The compound F12 also shows good evaporability in vacuum.

[0135] The experimental data of compounds F3 and F12 with the absorption properties and the current-voltage curves measured in organic solar cells demonstrate that compounds F3 and F12 are very well suited for use in organic solar cells and other organic optoelectronic devices.

[0136] Fig. Figure 5 shows a graphical representation of the absorption spectrum of reference compound F1 ( Fig. 5A), and the current-voltage curve, the spectral external quantum efficiency and the fill factor of a BHJ cell with the reference compound F1 ( Fig. 5B), measured on an organic optoelectronic component in the form of an organic solar cell.

[0137] Compound F1 shows a flat absorption curve with a slope of 2.75.

[0138] The current-voltage curve of a BHJ cell with the following structure: ITO / C60 (15 nm) / F1:C60 (30 nm, 3:2, 50°C) / BPAPF (10 nm) / BPAPF:NDP9 (30 nm, 10% wt NDP9) / NDP9 (1 nm) / Al (100 nm) was determined. The photoactive layer is a bulk heterojunction (BHJ). In the optoelectronic device with compound F1, the fill factor FF is 47.0%, the open-circuit voltage Uoc is 0.81 V, and the short-circuit current Jsc is 7.5 mA / cm2.

[0139] The experimental data of the reference compound F1 and the compounds F3 and F12 show that the compounds F3 and F12 have better absorption properties compared to the reference compound F1.

[0140] Fig. Figure 6 shows a graphical representation of a comparison of the absorption spectrum of compound F3 with a reference compound F1.

[0141] The absorption of compound F3 (shown with a solid line) and the reference compound F1 (shown with a dashed line) are plotted against photon energy. It is clearly visible that the absorption of compound F3, with a slope of 9.72, is significantly steeper than that of the reference compound F1, with a slope of 2.75.

Claims

[1] Compound of general formula I characterized by , that QO or S, preferably QS; R1 is selected from the group consisting of alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; X1 and X2 are independently N or C-R4; where R4 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; A1 is a group with the formula Ia, where * denotes the linkage to the compound of general formula I; Z1 is selected from the group consisting of O, S, Se, and N-R5, wherein R5 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y1 is N or C-R6, where R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; Y2 is N or C-R7, where R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R6 and R7 may be homocyclic or heterocyclic to each other in the form of a ring structure; R2 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; A2 is a group of the formula Ibis, where * denotes the linkage to the compound of the general formula I; Z2 is selected from the group consisting of O, S, Se, and N-R8, wherein R8 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; Y3 is N or C-R9, where R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; Y4 is N or C-R10, where R10 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and where R9 and R10 may be homocyclic or heterocyclic to each other in the form of a ring structure; and R3 is selected from the group consisting of H, halogen, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, branched or linear, cyclic or open-chain alkyl, amino, aryl, heteroaryl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F. [2] A compound according to claim 1, characterized by that R1 is selected from the group consisting of ethyl, propyl, butyl, branched alkyl, and aryl, preferably from isopropyl, isobutyl, sec-butyl, isopentyl, tert-butyl and phenyl; and where Z1 and Z2 are each independently O or S, preferably Z2 is O. [3] A compound according to any one of claims 1 or 2, characterized by that the compound is a compound of general formula II, where n is 0, 1 or 2 and m is 0, 1 or 2; QO or S, preferably QS; Z3 and Z4 are each independently selected from the group consisting of O, S, Se, and N-R11, where R11 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, and aryl; R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; wherein preferably Z3 and Z4 are independently O or S; Y5 is N or C-R14, wherein R14 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, wherein H may be substituted, wherein Y5 is preferably N, CH or CF; Y6 is N or C-R15, wherein R15 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, each of which H may be substituted, with Y6 preferably being N, CH or CF; Y7 is N or C-R16, wherein R16 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, each of which H may be substituted, with Y7 preferably being N, CH or CF; Y8 is N or C-R17, where R17 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted, where Y8 is preferably N, CH or CF; and wherein R14 and R15, and / or R16 and R17 together may form a homocyclic five-membered ring or six-membered ring, or a heterocyclic five-membered ring or six-membered ring having at least one heteroatom selected from the group consisting of S, O and N. [4] A compound according to any one of the preceding claims, characterized by , that A1 is a group of formula IIa, wherein R6 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; R7 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and wherein R6 and R7 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O and N; and A2 is a group of formula IIb, wherein R9 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, wherein H may be substituted; R10 is selected from the group consisting of H, halogen, alkoxy, branched or linear, cyclic or open-chain alkyl, alkenyl, and aryl, where H may be substituted; and wherein R9 and R10 together may form a homocyclic five-membered ring or six-membered ring, or a heterocyclic five-membered ring or six-membered ring having at least one heteroatom selected from the group consisting of S, O and N. [5] A compound according to any one of the preceding claims, characterized bythat the compound is a compound of general formula III, IV and / or V, where Q is O or S, preferably QS; Z1 and Z2 are each independently O or S, preferably Z2 is O; R6 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R7 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and wherein R6 and R7 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O and N; R9 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; R10 is selected from the group consisting of H, halogen, alkoxy, alkyl, and alkenyl, where H may be substituted; and where R9 and R10 together may form a homocyclic five-membered or six-membered ring, or a heterocyclic five-membered or six-membered ring having at least one heteroatom selected from the group consisting of S, O, and N; R12 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F; and R13 is selected from the group consisting of H, alkoxy, alkyl, fluorinated alkyl, partially fluorinated alkyl, alkenyl, and an electron-withdrawing alkyl group having at least one C=C double bond, where H may be substituted by CN or F. [6] A compound according to any one of the preceding claims, characterized bythat R2 and R3, or R12 and R13 are each independent of each other, where n is 1, 2 or 3, where * denotes the attachment of the group R2, R3, R12 and / or R13; R16, R17 and R18 are each independently selected from the group consisting of H, halogen, CN, COO-alkyl, alkyl and alkenyl, with the proviso that R16 and R17 are not both H, preferably R16 and R17 are CN. [7] A compound according to any one of the preceding claims, characterized by that R2 and R3, or R12 and R13 are each independently selected from the group consisting of: where * denotes the attachment of the group R2, R3, R12 and / or R13, where CN may be replaced by F, and where preferably R2 and R3, or R12 and R13 are the same. [8] A compound according to any one of the preceding claims, characterized by that R6 and R7 are H, R9 and R10 are H, and Z2 is O; preferably Z1 and Z2 are O. [9] A compound according to any one of the preceding claims, characterized by that the connection is selected from the group consisting of: [10] A compound according to any one of the preceding claims, characterized by that group A1 is equal to group A2. [11] Optoelectronic component comprising a first electrode (2), a second electrode (6) and a layer system (7), wherein the layer system is arranged between the first electrode (2) and the second electrode (6), characterized by that at least one layer of the layer system (7) has at least one compound according to one of claims 1 to 10. [12] Optoelectronic component according to claim 11, characterized by that the optoelectronic component is an organic optoelectronic component, preferably an organic solar cell, an OFET, an OLED or an organic photodetector. [13] Optoelectronic component according to claim 11 or 12, characterized bythat the layer system (7) has at least one photoactive layer (4), preferably an absorber layer, wherein the at least one photoactive layer (4) has the at least one compound according to one of claims 1 to 10, preferably the layer system (7) has at least two photoactive layers, preferably at least three photoactive layers, or preferably at least four photoactive layers. [14] Optoelectronic component according to one of claims 11 to 13, characterized by that the photoactive layer (4) is formed as a mixed layer of the at least one compound according to one of claims 1 to 10 and at least one further compound, or as a mixed layer of the at least one compound according to one of claims 1 to 10 and at least two further compounds, wherein the compounds are absorber materials. [15] Use of at least one compound according to one of claims 1 to 10 in an organic optoelectronic component, wherein the organic optoelectronic component is preferably an organic solar cell.

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