GB2623989A

GB2623989A - Compound

Info

Publication number: GB2623989A
Application number: GB2216325.7A
Authority: GB
Inventors: Yaacobi-Gross Nir; Maciejczyk Michal
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2022-11-02
Filing date: 2022-11-02
Publication date: 2024-05-08
Also published as: WO2024094804A1; GB202216325D0

Abstract

A compound of formula (I) or (II): A1-(B1)x1-(D1)y1-(B1)x2-A1 (I) A1-(B2)x5-(D2)y2-(B3)x3-A2-(B3)x4-(D3)y3-(B3)x6-A1 (II) A2 is a divalent heteroaromatic electron-accepting group; D1, D2 and D3 is independently an electron-donating group; B1, B2, and B3 is independently a bridging group; x1 to x6 are each independently 0, 1, 2 or 3; y1 and y2 are each independently at least 1; and each A1 is independently a group of formula (III): wherein each R1 is independently a substituent; R2, R3 and R4 are independently H or a substituent; J is C=O, C=S, NR11 or CR12R13, each Z1 is N and each Z2 is CR4, or each Z1 is CR4 and each Z2 is N. In other aspects, a composition comprising an electron-donating material wherein the electron accepting material is a compound of formula (I) or (II) and/or an organic electronic device comprising an active layer comprising said compound or composition. The organic electronic device may be an organic photoresponsive device comprising a bulk heterojunction layer disposed between an anode and a cathode and wherein the bulk heterojunction layer comprises said composition. The organic photoresponsive device may be an organic photodetector, which may be to detect light emitted from a light source.

Description

COMPOUND

BACKGROUND

Embodiments of the present disclosure relate to electron-accepting compounds and more specifically compounds suitable for use as an electron-accepting material in a photoresponsive device.

An organic photodetector may contain a photoactive layer of a blend of an electron-donating material and an electron-accepting material between an anode and a cathode. Known electron-accepting materials include fullerenes and non-fullcrene acceptors (NFAs).

io Yang et al, "End-capped group manipulation of indacenodithicnothiophene-based non-fullerene small molecule acceptors for efficient organic solar cells" Nanoscale, 2020, 12, 17795-17804 discloses the non-fullerene acceptor ITIC with a series of fused ring end groups for solar cells.

Wang et al. -Enhancement of Ultra-and inter-molecular it-conjugated effects for a non-fullerene acceptor to achieve high-efficiency organic solar cells with an extended photoresponse range and optimized morphology", Mater. Chem. Front., 2018, 2, 2006-2012 discloses an A-D-A type non-fullerene electron acceptor for solar cells which possesses an electron-donating (D) core constructed by linking a 2,5-ditluorobenzene ring with two cyclopentadithiophene moieties and two electron-accepting (A) end-groups of 2-(3-oxo-2,3-dihydro-1H-cyclopenta [h]naphthalen--ylidene)malononitrile.

Swick et al, Fluorinating it-Extended Molecular Acceptors Yields Highly Connected Crystal Structures and Low Reorganization Energies for Efficient Solar Cells" discloses the compounds ITN-F4 and lTzN-F4 for solar cells: -9 -

ON

Wu et al, "New Electron Acceptor with End-Extended Conjugation for High-Performance Polymer Solar Cells", Energy Fuels 2021, 35, 23, 19061-19068 discloses the compound 1DTT8-N for solar cells: MITe Li et al, "Systematic Merging of Nonfullerene Acceptor 7E-Extension and Tetrafluorination Strategies Affords Polymer Solar Cells with >16% Efficiency" discloses the non-fullerene acceptors BT-BIC, LIC. L4F. and BO-L4F for solar cells:

SUMMARY

The present disclosure provides a compound of formula (I) or (II): A -(B)x -(D I)y I -(B I)x2 -A I (I) A' -(B2)x5 -(D2)y2 -(B3) A2 -(B3)x4 -(D3)y3 -(B 2)x6 -A' (II) _to wherein: A2 is a divalent heteroaromatic electron-accepting group; Di, D2 and D3 independently in each occurrence is an electron-donating group; B1, B2, and B3 independently in each occurrence is a bridging group; x I and x2 are each independently 0, 1, 2 or 3; is yl and y2 are each independently at least 1; A1 in each occurrence is independently a group of formula (IlI): -4 -wherein: each R1 is independently a substituent; each R3 is independently H or a substituent; J is C=0, C=S, NRit or cRi2tc -13 wherein R" is CN or COOR4° and R4° is H or a substituent and R12 and R13 are each independently CN, CF3 or C00R40; and either each Z1 is N and each Z2 is CR4, or each Z1 is CR4 and each Z2 is N wherein each io R4 is independently H or a substituent.

Optionally, each R1 is independently selected from CN, CF3 and COOR4° wherein R4° in each occurrence is H or a substituent. R4° is preferably H or a C1_20hydrocarbyl group.

Optionally, each 123 is an electron-withdrawing group.

Optionally, the electron-withdrawing group is selected from Cl, F. CN, Ci_12 flUOrOalkyi /5 and COOR15 wherein R15 is a Cirio hydrocarbyl group.

Optionally, each R4 is independently selected from H or an electron-withdrawing group.

The present disclosure provides a composition comprising an electron-donating material and an electron-accepting material wherein the electron accepting material is a compound according to any one of the preceding claims.

The present disclosure provides an organic electronic device comprising an active layer 5 comprising a compound or composition as described herein.

Optionally, the organic electronic device is an organic photoresponsive device comprising a bulk heterojunction layer disposed between an anode and a cathode and wherein the bulk heterojunction layer comprises a composition as described herein.

Optionally, the organic photoresponsive device is an organic photodetector.

The present disclosure provides a photosensor comprising a light source and an organic photodetector as described herein wherein the photosensor is configured to detect light emitted from the light source.

Optionally, the light source emits light having a peak wavelength of greater than 900 nm.

The present disclosure provides a formulation comprising a compound or composition as /5 described herein dissolved or dispersed in one or more solvents.

The present disclosure provides a method of forming an organic electronic device as described herein wherein formation of the active layer comprises deposition of a formulation as described herein onto a surface and evaporation of the one or more solvents.

DESCRIPTION OF DRAWINGS

The disclosed technology and accompanying figures describe some implementations of the disclosed technology.

Figure 1 illustrates an organic photomsponsive device according to some embodiments; Figure 2 is a graph of wavelength vs extinction coefficient for a toluene solution of Compound Example 1 and a toluene solution of Comparative Compound 1; -6 -Figure 3 is a graph of wavelength vs normalised absorption for a film of Compound Example 1 and a film of Comparative Compound 1; Figure 4 is a graph of external quantum efficiency (EQE) vs wavelength for OPD Device Example 1 in which the only acceptor is Compound Example 1 and for OPD Device Example 2 in which the acceptors are Compound Example 1 and PCBM; Figure 5 is a graph of external quantum efficiency (EQE) vs wavelength for OPD Comparative Device 2 containing Comparative Compound 1 and PCBM; and Figure 6 shows dark current at a reverse bias of -3V for OPD devices containing Compound Example 1 and for OPD devices containing Comparative Compound 1.

io The drawings are not drawn to scale and have various viewpoints and perspectives. The drawings are some implementations and examples. Additionally, some components and/or operations may be separated into different blocks or combined into a single block for the purposes of discussion of some of the embodiments of the disclosed technology. Moreover, while the technology is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the technology to the particular implementations described. On the contrary, the technology is intended to cover all modifications, equivalents, and alternatives falling within the scope of the technology as defined by the appended claims.

DETAILED DESCRIPTION

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to." Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word "or," in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of -7 -the items in die list, and any combination of the items in the list. References to a layer "over" another layer when used in this application means that the layers may be in direct contact or one or more intervening layers may be present. References to a layer "on" another layer when used in this application means that the layers are in direct contact.

References to a specific atom include any isotope of that atom unless specifically stated otherwise.

The teachings of the technology provided herein can be applied to other systems, not necessarily the system described below. The elements and acts of the various examples described below can be combined to provide further implementations of the technology.

ro Some alternative implementations of the technology may include not only additional elements to those implementations noted below, but also may include fewer elements.

These and other changes can be made to the technology in light of the following detailed description. While the description describes certain examples of the technology, and describes the best mode contemplated, no matter how detailed the description appears, the technology can be practiced in many ways. As noted above, particular terminology used when describing certain features or aspects of the technology should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the technology to the specific examples disclosed in the specification, unless the Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the technology encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the technology under the claims.

To reduce the number of claims, certain aspects of the technology are presented below in or certain claim forms, but the applicant contemplates the various aspects of the technology in any number of claim forms.

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that -8 -embodiments of the disclosed technology may be practiced without some of these specific details.

The formulae (I) and (II) are Al -(B1)x' -(D1)y1 -(B1)x2 -(I) A1 -(B2)x.' -(D2)y2 -(133)x3-A2 -(B3)x4 -(133)y3 -(B2)x6 -A1 (II) A1 is a monovalent electron-accepting group.

A2 is a divalent heteroaromatic electron-accepting group.

D1, D2 and D3 independently in each occurrence is an electron-donating group.

B2, and B3 independently in each occurrence is a bridging group.

-x6 are each independently 0, 1,2 or 3, preferably 0 or 1.

x1 and x2 are preferably the same and are preferably both 0 or both 1.

x3 and x4 are preferably the same and are preferably both 0 or both 1, more preferably both 0.

x5 and x6 are preferably the same and are preferably both 0 or both I. y2 and y3 are each independently at least 1, preferably 1, 2 or 3. y2 and y3 are preferably the same. -9 -

Each of the electron-accepting groups Al. A2 and A3 has a lowest unoccupied molecular orbital (LUMO) level that is deeper (i.e.. further from vacuum) than the LUMO of any of the electron-donating groups DI, D2 or D3 of the compound of formula (I), preferably at least 1 eV deeper. The LUMO levels of electron-accepting groups and electron-donating groups may be as determined by modelling the LUMO level of these groups, in which each bond to adjacent group is replaced with a bond to a hydrogen atom. Modelling may be performed using Gaussian09 software available from Gaussian using Gaussian09 with B3LYP (functional) and LACVP* (Basis set).

A1 in each occurrence is independently a group of formula (III): Each R1 is independently a substituent. Preferably, each RI is independently selected from CM; C1.6 fluoroalkyl, preferably CF3; and COOR4° wherein R4° in each occurrence is H or a substituent, preferably H or a CI -20 hydrocarbyl group.

is A C1-20 hydrocarbyl group as described herein may be selected from phenyl which may be unsubstituted or substituted with one or more substituents selected from Clip alkyl and a linear, branched or cyclic Ch20 alkyl.

R2 is H or a substituent. Preferably, R2 is H, F, Cl, CN, NO2, C1_16 alkyl or C1-16 alkoxy wherein one or more H atoms of the CI-16 alkyl or CI-16 alkoxy may be replaced with F. -10 -Each R3 is independently H or a substituent, preferably an electron-withdrawing group. Preferred electron-withdrawing groups are F, Cl, CN, C112 fluoroalkyl and COOR15 wherein RIs is a C 1_20 hydrocarbyl group.

J is C=0, C=S, NR or CR12R13 wherein 1211. R12 and R13are as described above. J is preferably C=0.

Either: (i) each Z1 is N and each Z2 is CR4, or (b) each Z1 is CR4 and each Z2 is N wherein each R4 is independently H or a substituent, preferably H or an electron-withdrawing group. Electron-withdrawing groups R4 are preferably selected from electron-withdrawing groups described with respect to R3.

_to Preferably, the group of formula (III) has fommla (Ma): Exemplary groups of formula (III) include, without limitation: In some embodiments, the compound of formula (T) or (H) has an absorption peak greater than 900 nm, optionally greater than 1100 nm, optionally greater than 1250 nm. The absorption peak is suitably less than 1500 nm.

The present inventors have surprisingly found that compounds of formula (I) or (II) having a group Al of formula (III) may have low dark current.

Acceptor Unit A2 A2 is preferably a fused heteroaromatic group comprising at least 2 fused rings, preferably at least 3 fused rings.

_to In some embodiments, A2 of formula (II) is a group of formula (VIII): -12 -wherein: Arl is an aromatic or heteroaromatic group; and Y is 0, S, NR6 or R7-C=C-R7 wherein R7 in each occurrence is independently H or a substituent wherein two substituents R7 may be linked to form a monocyclic or polycyclic ring; and R6 is H or a substituent.

In the case where A2 is a group of formula (VIII). Ari may be a monocyclic or polycyclic heteroaromatic group which is unsubstituted or substituted with one or more R9 groups _to wherein R9 in each occurrence is independently a substituent.

Preferred R9 groups are selected from F; CN; NO2; Ci_20 alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S, NR 17 wherein R17 is a Ci_17 hydrocarbyl, COO or CO and one or more H atoms of the alkyl may be replaced with F; an aromatic or heteroaromatic group, preferably phenyl, which is unsubstituted or substituted with one or more substituents; and a group selected from Y40 -13 -R40 9;1 w41 z40 Z43.-z42 or Z41. L12 and -z. wherein Z4°, are each independently CR13 or N wherein Rn in each occurrence is H or a substituent, preferably a C1_20 hydrocarbyl group; y40 and y41 are each independently 0, S. NX71 wherein X71 is CN or C00R40; or CX ooxoi wherein X6° 5 and X61 is independently CN, CF3 or C00R40; W4° and W41 are each independently 0, S, NX71 or CX60X61 wherein X6° and X61 is independently CN, CF3 or C00R40; and R4° in each occurrence is H or a substituent, preferably H or a C1-20 hydrocarbyl group. Exemplary substituents of an aromatic or heteroaromatic group R9 are F, CN, NOn, and C1_12 alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S, NR7, 10 COO or CO and one or more H atoms of the alkyl may be replaced with F. R17 as described anywhere herein may be, for example, C1_12 alkyl, unsubstituted phenyl; or phenyl substituted with one or more C1-6 alkyl groups.

If a C atom of an alkyl group as described anywhere herein is replaced with another atom or group, the replaced C atom may be a terminal C atom of the alkyl group or a non-C-atom.

By "non-terminal C atom" of an alkyl group as used anywhere herein means a C atom other than the C atom of the methyl group at the end of an n-alkyl chain or the C atoms of the methyl groups at the ends of a branched alkyl chain.

If a terminal C atom of a group as described anywhere herein is replaced then the resulting group may be an anionic group comprising a countercation, e.g., an ammonium or metal countercation, preferably an ammonium or alkali metal cation.

A C atom of an alkyl substituent group which is replaced with another atom or group as described anywhere herein is preferably a non-terminal C atom, and the resultant substituent group is preferably non-ionic. 14 -

Exemplary monocyclic heteroaromatic groups Arl are oxadiazole, thiadiazole, triazole and 1,4-diazine which is unsubstituted or substituted with one or more substituents. Thiadiazole is particularly preferred.

Exemplary polycyclic heteroaromatie groups AO are groups of formula (V): (V) X1 and X2, are each independently selected from N and CR1° wherein RI° is H or a substituent, optionally H or a substituent R9 as described above.

X3, X4, Xs and X6 are each independently selected from N and CR1° with the proviso that to at least one of X', X4, X5 and X6 is CRI°.

Z is selected from 0, S, SO,, NR6, PR6, C(R10)2, Si(R1°)2 C=0, C=S and C=C(W)2 wherein RI° is as described above; R6 is H or a substituent; and R5 in each occurrence is an electron-withdrawing group.

Optionally, each R6 of any NR6 or PR6 described anywhere herein is independently selected from H; C1220 alkyl wherein one or more non-adjacent C atoms other than the C atom bound to N or P may be replaced with 0, S. NR7, COO or CO and one or more H atoms of the alkyl may be replaced with F; and phenyl which is unsubstituted or substituted with one or more substituents, optionally one or more C112 alkyl groups wherein one or more non-adjacent C atoms of the alkyl may be replaced with 0, S, NR7, COO or CO and one or more H atoms of the alkyl may be replaced with F. -15 -Preferably, each R5 is CN, C00R40; cxooxoi wherein x6o and x61 is independently CN, CF3 or COOR4° and R4° in each occurrence is H or a substituent, preferably H or a Ci_2o hydrocarbyl group.

A2 groups of formula (VIII) are preferably selected from groups of formulae (VIna) and 5 (VIIIb): NR)

N N %

(VIITa) (VIIIb) For compounds of formula (VIIIb), the two R7 groups may or may not be linked Preferably, when the two R7 groups are not linked each R7 is independently selected from _to H; F; CN; NO2; C1_20 alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S. NR7, CO, COO, NR6, PR6, or Si(R)2 wherein RI° and R6 are as described above and one or more H atoms may be replaced with F; and aryl or heteroaryl, preferably phenyl, which may be unsubstituted or substituted with one or more substituents. Substituents of the aryl or heteroaryl group may be selected from one or more of F; CN; /5 NO,; and C1_20 alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S. NR7, CO, COO and one or more I-I atoms may be replaced with F. Preferably, when the two 12.7 groups are linked, the group of formula (V Illb) has formula (VIIIb-1) or (VIIIb-2): -16 -(VIIIb-2) Ar2 is an aromatic or heteroaromatic group, preferably benzene, which is unsubstituted or substituted with one or more substituents. Ar2 may be unsubstituted or substituted with 5 one or more substituents R2 as described above X is selected from 0.5, 502, NR6, PR6, C(R10)2, Si(R10)2 C=0, C=S and C=C(R5)2 wherein RI°, R6 and R5 are as described above.

Exemplary electron-accepting groups of formula (VIII) include, without limitation: Ale Ale

N

N N \''' -S, N"N

N N

AO AO 0,N,

wherein Ak I is a C1 _20 alkyl group Divalent electron-accepting groups A2 other than formula (VIII) are optionally selected from formulae (IVa)-(IVD (IVb) R25 (lye) R25 N N (lVd) -18 -R12 (IVe) R25 R25 (IVO I vi N\ in c N'N (Dig) (TVI) (IVO (11V) R" YAI is 0 or S. preferably S. R23 in each occurrence is a substituent, optionally Cm, alkyl wherein one or more nonadjacent C atoms other than the C atom attached to Z3 may be replaced with 0, S, NR6, COO or CO and one or more H atoms of the alkyl may be replaced with F. R2 in each occurrence is independently H; F; CN; NOn; Ci_i, alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S, NR6, COO or CO and one or more H atoms of the alkyl may be replaced with F; an aromatic group, optionally phenyl, which is unsubstituted or substituted with one or more substituents selected from F and CIA, alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S, NR6, COO ll.) or CO; or yao -19 -z40 ^-^z41 R40 z42 Z43' or w41 wherein z40, z41. L12 and z are each independently CR13 or N wherein Rn in each occurrence is H or a substituent, preferably a C1,20 hydrocarbyl group; Y4° and Y41 are each independently 0, S. NX71 wherein X71 is CN or C00R40, or CX60x61 5 wherein X6° and X61 is independently CN. CF3 or C00R40; W4° and W41 are each independently 0, S. NX71 wherein X71 is CN or C00R40, or CX60X61 wherein X60 and X61 is independently CN, CF, or COOR4°; and R4° in each occurrence is II or a substituent, preferably II or a C1-20 hydrocarbyl group. Z3 is N or P. T1, T2 and T3 each independently represent an aryl or a heteroaryl ring, optionally benzene, which may be fused to one or more further rings. Substituents of T I, T2 and T3, where present, are optionally selected from non-H groups of R25 In a preferred embodiment. T3 is benzothiadiazole.

R12 in each occurrence is a substituent, preferably a C1,20 hydrocarbyl group.

Ars is an arylene or heteroarylene group, optionally thiophene, fluorene or phenylene, which may be unsubstituted or substituted with one or more substituents, optionally one or more non-H groups selected from R25.

Bridging units Bridging units B'. B2 and B3 are preferably each selected from vinylene, arylene, heteroarylene, arylenevinylene and heteroarylenevinylene wherein the arylene and heteroarylene groups are monocyclic or bicyclic groups, each of which may be unsubstituted or substituted with one or more substituents.

Optionally, B1, B2 and B3 are selected from units of formulae (VIa) -(VIn): -20 -R8 R8 R8 R8 R8 R55 (VIa) (VIb) (Vic) (VId) c. R55

(Vie) (VII) (Vkg) (V111) (VII) (VU) (V1k) (VII) R8 R8 (VIm) (VIn) wherein R55 is H or a substituent; R8 in each occurrence is independently H or a substituent, preferably H or a substituent selected from F; CN; NO2; C1_20 alkyl wherein one or more non-adjacent C atoms may he replaced with 0, S. MR°, COO or CO and one or more H atoms of the alkyl may be replaced with F; phenyl which is unsubstituted or substituted with one or more substituents; and -B(R14)7 wherein RN in each occurrence is -21-a substituent, optionally a Cirio hydrocarbyl group. R8 groups of formulae (Via), (V lb) and (Vic) may be linked to form a bicyclic ring, for example thicnopyrazine.

R8 is preferably H. CI -20 alkyl or Ci_19 alkoxy. Electron-Donating Groups DI. D2 and D3 Electron-donating groups preferably are fused aromatic or heteroaromatic groups, more preferably fused heteroaromatic groups containing three or more rings. Particularly preferred electron-donating groups comprise fused thiophene or furan rings, optionally fused rings containing thiophene or furan rings and one or more rings selected from benzene, cyclopentadiene, tctrahydropyran, tetrahydrothiopyran and piperidine rings, _to each of said rings being unsubstituted or substituted with one or more substituents.

Exemplary electron-donating groups Di, D2 and D3 include groups of formulae (VIIa)-(V11p): (VIM) (VHc) R" R5' R52 (V lid) R53 R53 R51 11P (V I le) R51 R53 R53 R54 R54 (VIII) (Vng) R54 R5' R51 R5' R51 R54 R54 (VIIh) R54 R54 R54 R54 R54 (VIEk) R51 R51 R54 R54 ( (VIII) (V[Im) R R5,3 51,R53 )(A R51 (V1In) (V11o) R52 R52 R52 R52 R52 R52 R55 (VIIp) wherein VA in each occurrence is independently a S or NR55, YA1 in each occurrence is independently 0 or S; XA is C or Si; ZA in each occurrence is 0, CO, S, NR55 or C(R54)2; R51, R52 R54 and R55 independently in each occurrence is H or a substituent; R53 independently in each occurrence is a substituent; and Ar4 is an optionally substituted monocycle or fused heteroaromatic group.

Optionally, R51 and R52 independently in each occurrence are selected from H; F; C1_20 alkyl wherein one or more non-adjacent C atoms may be replaced with 0, 5, NR7, COO or CO and one or more H atoms of the alkyl may he replaced with F; and an aromatic or heteroaromatic group Ar3 which is unsubstituted or substituted with one or more In some embodiments, Ar3 may be an aromatic group, e.g., phenyl.

Ar4 is preferably selected from optionally substituted oxadiazole, thiadiazole, triazole, and 1,4-diazine. In the case where Ar4 is 1,4-diazine, the 1,4-diazine may be fused to a further heterocyclic group, optionally a group selected from optionally substituted oxadiazole, thiadiazole, triazole, 1,4-diazine and succinimide.

The one or more substituents of Ar3, if present, may be selected from C1-12 alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S. NR7, COO or CO and one or more H atoms of the alkyl may be replaced with F. Preferably, each R54 is selected from the group consisting of: -24 -F; linear, branched or cyclic Ci_/0 alkyl wherein one or more non-adjacent C atoms may be replaced by 0, S. NR7, CO or COO wherein R17 is a Ci_nhydrocarbyl and one or more H atoms of the C1_20 alkyl may be replaced with F; and a group of formula (Ak)u-(Ae)v wherein Ak is a Ci_lo alkylene chain in which one or more non-adjacent C atoms may be replaced with O. 5, NR7, CO or COO; u is() or 1; Ar7 in each occurrence is independently an aromatic or hetcroaromatic group which is unsubstituted or substituted with one or more substituents; and v is at least 1, optionally 1, 2 or 3.

/0 Substituents of Ar7, if present, are preferably selected from F; Cl; NO2; CN; and C Lir) alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S, NR7, CO or COO and one or more H atoms may be replaced with F. Preferably, Ar7 is phenyl.

Preferably, each R51 is H. Optionally, R53 independently in each occurrence is selected from C1_20 alkyl wherein one /5 or more non-adjacent C atoms may be replaced with 0, S. NR7, COO or CO and one or more H atoms of the alkyl may be replaced with F; and phenyl which is unsubstituted or substituted with one or more substituents, optionally one or more Ci_p alkyl groups wherein one or more non-adjacent C atoms may be replaced with 0, 5, NR7, COO or CO and one or more H atoms of the alkyl may be replaced with F. Preferably, R55 as described anywhere herein is H or Ci_30 hydrocarbyl group.

In a preferred embodiment, DI. D2 and D3 are each independently a group of formula (Vila). Exemplary groups of formula (VIIa) include, without limitation: 0 Tic He He Hc -25 -He-,N He Hc wherein He in each occurrence is independently a C1.20 hydrocarbyl group, e.g.. C1-20 alkyl, unsubstituted aryl, or aryl substituted with one or more C1-12 alkyl groups. The aryl group is preferably phenyl.

In some embodiments, y of formula (I) is 1.

In some embodiments, y2 and y3 of formula (II) are each 1.

In some embodiments, y1 of formula (I) or at least one of y2 and y3 of formula (II) is greater than 1. In these embodiments, the chain of D', D2 or D3 groups, respectively, may be linked in any orientation. For example, in the case where DI is a group of formula (Vita) and yI is 2, -1Dllyt-may be selected from any of: YA yA R54 R51 12: R54 R51 i4 R54 Exemplary compounds of formula (1) include, without limitation: -26 -NC CN N./

CI CI

Electron-donating material

NC

-27 -

CI CI *0 0$

in S N S t a It t 4N * I. NS

CN

CN CN

A bulk heterojunction layer as described herein comprises an electron-donating material and a compound of formula (I) as described herein.

Exemplary donor materials are disclosed in, for example. W02013/051676, the contents of which are incorporated herein by reference.

The electron-donating material may be a non-polymeric or polymeric material.

In a preferred embodiment the electron-donating material is an organic conjugated polymer, which can be a homopolymer or copolymer including alternating, random or _to block copolymers. The conjugated polymer is preferably a donor-acceptor polymer comprising alternating electron-donating repeat units and electron-accepting repeat units.

Preferred are non-crystalline or semi-crystalline conjugated organic polymers.

Further preferably the electron-donating polymer is a conjugated organic polymer with a low bandgap, typically between 2.5 eV and 1.5 eV, preferably between 2.3 eV and 1.8 15 eV.

Optionally, the electron-donating polymer has a HOMO level no more than 5.5 eV from vacuum level. Optionally, the electron-donating polymer has a HOMO level at least 4.1 eV from vacuum level. As exemplary electron-donating polymers, polymers selected -28 - from conjugated hydrocarbon or heterocyclic polymers including polyacene, polyaniline, polyazulene. polybenzofuran, polyfluorene, polyfuran, polyindenofluorene, polyindole, polyphenylene, polypyrazoline, polypyrene, polypyridazine, polypyridine, polytriarylamine, poly(phenylene vinylene), poly( 3-substituted thiophene), poly( 3,4- bisubstituted thiophene), polyselenophene, poly(3-substituted selenophene), poly(3,4-bisubstituted selenophene), poly(bisthiophene), poly(terthiophene), poly(bisselenophene), poly(terselenophene), polythienol2,3-b]thiophene, polythieno[3,2-frithiophene, polybenzothiophene, polybenzo[1,2-b:4,5-bldithiophene, polyisothianaphthene, poly(monosubstituted pyrrole), poly(3.4-bisubstituted pyrrole), poly-1,3,4-oxadiazoles, polyisothianaphthene, derivatives and co-polymers thereof may be mentioned.

Preferred examples of donor polymers are copolymers of polyfluorenes and polythiophenes, each of which may be substituted, and polymers comprising benzothiadiazole-based and thiophene-basal repeating units, each of which may be /5 substituted.

A particularly preferred donor polymer comprises donor unit (VIIa) provided as a repeat unit of the polymer, most preferably with an electron-accepting repeat unit, for example divalent electron-accepting units A1 as described herein provided as polymeric repeat units.

Another particularly preferred donor polymer comprises repeat units of formula (X): wherein R18 and 1219 are each independently selected from H; F; CIA, alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with 0, S, COO or CO 25 and one or more H atoms of the alkyl may be replaced with F; or an aromatic or -29 -heteroaromatic group Ar6 which is unsubstituted or substituted with one or more substituents selected from F and Ci_p alkyl wherein one or more non-adjacent. non-terminal C atoms may be replaced with 0, S. COO or CO.

The donor polymer is preferably a donor-acceptor (DA) copolymer comprising a donor repeat unit, for example a repeat unit of formula (VHa) or (X), and an acceptor repeat unit.

Organic Electronic Device A compound of formula (I) or (11) may be provided as an active layer of an organic electronic device. In a preferred embodiment, a bulk heterojunction layer of an organic 10 photoresponsive device, more preferably an organic photodetector, comprises a composition as described herein The bulk heterojunction layer comprises or consists of an electron-donating material and an electron-accepting compound of formula (1) or (H) as described herein.

In some embodiments, the bulk heterojunction layer contains two or more accepting materials and! or two or more electron-accepting materials.

hi some embodiments, the weight of the electron-donating material(s) to the electron-accepting material(s) is from about 1:0.5 to about 1:2, preferably about 1:1.1 to about 1:2.

Preferably, the electron-donating material has a type II interface with the electron-accepting material, i.e. the electron-donating material has a shallower HOMO and LUMO that the corresponding HOMO and LUMO levels of the electron-accepting material. Preferably, the compound of formula (T) or (IT) has a HOMO level that is at least 0.05 eV deeper, optionally at least 0.10 eV deeper, than the HOMO of the electron-donating material.

Optionally, the gap between the HOMO level of the electron-donating material and the LUMO level of the electron-accepting compound of formula (I) or (II) is less than 1.4 eV.

Unless stated otherwise, HOMO and LUMO levels of materials as described herein are as measured by square wave voltammetry (SWV). a

Figure 1 illustrates an organic photoresponsive device according to some embodiments of the present disclosure. The organic photoresponsive device comprises a cathode 103, an anode 107 and a bulk heterojunction layer 105 disposed between the anode and the cathode. The organic photoresponsive device may be supported on a substrate 101, optionally a glass or plastic substrate.

Each of the anode and cathode may independently he a single conductive layer or may comprise a plurality of layers.

At least one of the anode and cathode is transparent so that light incident on the device may reach the bulk heterojunction layer. In some embodiments, both of the anode and _to cathode are transparent. The transmittance of a transparent electrode may be selected according to an emission wavelength of a light source for use with the organic photodetector.

Figure 1 illustrates an arrangement in which the cathode is disposed between the substrate and the anode. In other embodiments, the anode may be disposed between the cathode 7.5 and the substrate.

The organic photoresponsive device may comprise layers other than the anode, cathode and bulk heterojunction layer shown in Figure 1. In some embodiments, a hole-transporting layer is disposed between the anode and the bulk heterojunction layer. In some embodiments, an electron-transporting layer is disposed between the cathode and the bulk heterojunction layer. In some embodiments, a work function modification layer is disposed between the bulk heterojunction layer and the anode, and/or between the bulk heterojunction layer and the cathode.

The area of the OPD may be less than about 3 cm2, less than about 2 cm2, less than about I cm, less than about 0.75 cm2, less than about 0.5 cm2 or less than about 0.25 cm.

Optionally, each OPD may be part of an OPD array wherein each OPD is a pixel of the array having an area as described herein, optionally an area of less than 1 mm2, optionally in the range of 0.5 micron= -900 micron'''.

The substrate may be, without limitation, a glass or plastic substrate. The substrate can be an inorganic semiconductor. In some embodiments, the substrate may be silicon. For -31 -example, the substrate can be a wafer of silicon. The substrate is transparent if, in use, incident light is to be transmitted through the substrate and the electrode supported by the substrate.

The bulk heterojunction layer contains a compound of formula (I) or (II) as described herein and an electron-donating compound. The bulk heterojunction layer may consist of these materials or may comprise one or more further materials, for example one or more further electron-donating materials and / or one or more further electron-accepting compounds.

Fullerene io In some embodiments, a compound of formula (I) or (II) is the only electron-accepting material of a bulk heteroj unction layer as described herein.

In some embodiments, a bulk heterojuction layer contains a compound of formula (I) or (II) and one or more further electron-accepting materials. Preferred further electron- /5 accepting materials are fullerenes. The present inventors have surprisingly found that a combination of a compound of formula (I) or (II) and a fullerene may enhance external quantum efficiency of an OPD with little or no increase in dark cunent.

The compound of formula (I) or (II) : fullerene acceptor weight ratio may be in the range of about 1: 0.1-1: 1, preferably in the range of about 1: 0.1-1: 0.5.Fullerenes may be selected from, without limitation, C60, C70, C76, C7g and Ow fullerenes or a derivative thereof, including, without limitation, PCBM-type fullerene derivatives including Oen yiCed butyric acid methyl ester (C60PC.:13M), TCBM-type fullerene derivatives (e.g. tolylCol-butyric acid methyl ester (C60TCBM)), and ThCBM-type fullerene derivatives (e.g. thienyl-C61-butyric acid methyl ester (C60ThCBM).

Fullerene derivatives may have formula (V): -32 -(V) wherein A. together with the C-C group of the fullerene, forms a monocyclic or fused ring group which may be unsubstituted or substituted with one or more substituents.

Exemplary fullerene derivatives include formulae (Va), (Vb) and (Vc): R21

C-

FL LLERENE \11", (Va) R23 (Vb) (Vc)

wherein R20-R32 are each independently H or a substituent.

Substituents R20-R32 are optionally and independently in each occurrence selected from the group consisting of aryl or heteroaryl, optionally phenyl, which may be unsubstituted or substituted with one or more substituents; and C1-20 alkyl wherein one or more nonadjacent C atoms may be replaced with 0, S. NR7, CO or COO and one or more H atoms may be replaced with F. -33 -Substituents of aryl or heteroaryl, where present, are optionally selected from Ci_p alkyl wherein one or more non-adjacent C atoms may be replaced with 0, S. NR7, CO or COO and one or more H atoms may be replaced with F. Formulations r The bulk heterojunction layer may be formed by any process including, without limitation, thermal evaporation and solution deposition methods.

Preferably, the bulk heterojunction layer is formed by depositing a formulation comprising the electron-donating material(s), the electron-accepting material(s) and any other components of the bulk heterojunction layer dissolved or dispersed in a solvent or _to a mixture of two or more solvents. The formulation may be deposited by any coating or printing method including, without limitation, spin-coating, dip-coating, roll-coating, spray coating, doctor blade coating, wire bar coating, slit coating, ink jet printing, screen printing, gravure printing and flexographic printing.

The one or more solvents of the formulation may optionally comprise or consist of benzene or naphthalene substituted with one or more substituents selected from fluorine, chlorine, Ci_10 alkyl and Ci_io alkoxy wherein two or more substituents may be linked to form a ring which may be unsubstitutcd or substituted with one or more C1_6 alkyl groups, optionally toluene, xylenes, trimethylbenzenes, tetramethylbenzenes, anisole, indane and its alkyl-substituted derivatives, and tetralin and its alkyl-substituted derivatives.

The formulation may comprise a mixture of two or more solvents, preferably a mixture comprising at least one benzene substituted with one or more substituents as described above and one or more further solvents. The one or more further solvents may be selected from esters, optionally alkyl or aryl esters of alkyl or aryl carboxylic acids, optionally a C1_10 alkyl benzoate, benzyl benzoate or dimethoxybenzene. In preferred embodiments, a mixture of trimethylbenzene and benzyl benzoate is used as the solvent. In other preferred embodiments, a mixture of trimethylbenzenc and dimethoxybenzene is used as the solvent.

The formulation may comprise further components in addition to the electron-accepting material, the electron-donating material and the one or more solvents. As examples of -34 -such components, adhesive agents, deloamin2 agents, deaerators, viscosity enhancers, diluents, auxiliaries, flow improvers colourants, dyes or pigments, sensitizers, stabilizers, nanoparticles, surface-active compounds, lubricating agents, wetting agents, dispersing agents and inhibitors may be mentioned.

Applications A circuit may comprise the OPD connected to a voltage source for applying a reverse bias to the device and / or a device configured to measure photocurrent. The voltage applied to the photodetector may be variable. In some embodiments, the photodetector may be continuously biased when in use.

if7 In some embodiments, a photodetector system comprises a plurality of photodetectors as described herein, such as an image sensor of a camera.

In some embodiments, a sensor may comprise an OPD as described herein and a light source wherein the OPD is configured to receive light emitted from the light source. In some embodiments, the light source has a peak wavelength of at least 900 nm or at least 1000 nm, optionally in the range of 900-1500 nm.

In some embodiments, the light from the light source may or may not be changed before reaching the OPD. For example, the light may be reflected, filtered, down-converted or up-converted before it reaches the OPD.

The organic photoresponsive device as described herein may be an organic photovoltaic device or an organic photodetector. An organic photodetector as described herein may be used in a wide range of applications including, without limitation, detecting the presence and / or brightness of ambient light and in a sensor comprising the organic photodetector and a light source. The photodetector may be configured such that light emitted from the light source is incident on the photodetector and changes in wavelength and/or brightness -0 or of the light may be detected, e.2., due to absorption by, reflection by and/or emission of flat from an object, e.g. a target material in a sample disposed in a light path between the light source and the organic photodetector. The sample may be a non-biological sample, e.g. a water sample, or a biological sample taken from a human or animal subject. The sensor may be, without limitation, a gas sensor, a biosensor, an X-ray imaging device, -35 -an image sensor such as a camera image sensor, a motion sensor (for example for use in security applications) a proximity sensor or a fingerprint sensor. A 1D or 2D photosensor array may comprise a plurality of photodetectors as described herein in an image sensor. The photodetector may be configured to detect light emitted from a target analyte which emits light upon irradiation by the light source or which is bound to a luminescent tag which emits light upon irradiation by the light source. The photodetector may be configured to detect a wavelength of light emitted by the target. analyte or a luminescent tag hound thereto.

Examples

o Example 1

A group of formula (111-1) may be formed according to the following reaction scheme: NBS 0 0 H 2 N H 2 N CI CI Step 1 CI Step 2 0 0 3

C I C I C I

Step 3 C I C I C I COOtBu 0 0 6 7A C I Malononitrile (1 eq) CI CI Step 5A CI Step 6 C N

NC

Example 2

A group of formula (III-2) may he formed according to the following reaction scheme: -36 -Step 4 COOtBu

CN

Malononitrile (1 eq) Step 6 HO,jt,° NBS OH Step 1 H2N H2N 7A 111-2 -37 -

Example 3

A group of formula (111-3) may he formed according to the following reaction scheme:

NBS

OH Step 1

HO

H N

p-Ts0H, Br Step 2 Br Step 3 Br 111-3 K4[Fe(CN)61 NC Step 7 NC Malononitrile (1 eq) 0 Step 9

NC

CN

NC

Step 8 NC -38 -

Compound Example I

Compound Example I may be formed according to the following reaction scheme: C6F113 CeH13 C6I-113 C6H13 R3sn -39 -Measurement methods HOMO and LUMO levels were measured by square wave voltammetry (SWV).

In SWV, the current at a working electrode is measured while the potential between the working electrode and a reference electrode is swept linearly in time. The difference current between a forward and reverse pulse is plotted as a function of potential to yield a voltammogram. Measurement may be with a CHI 660D Potentiostat.

The apparatus to measure HOMO or LUMO energy levels by SWV comprises a cell containing 0.1 M tertiary butyl ammonium hexafluorophosphate in acetonitrile; a 3 mm diameter glassy carbon working electrode; a platinum counter electrode and a leak free 10 Ag/AgC1 reference electrode.

Ferrocene is added directly to the existing cell at the end of the experiment for calculation purposes where the potentials are determined for the oxidation and reduction of fen-ocene versus Ag/AC1 using cyclic voltammetry (CV).

The sample is dissolved in toluene (3 mg / ml) and spun at 3000 rpm directly on to the /5 glassy carbon working electrode.

LUMO = 4.8-E fenocene (peak to peak average) -E reduction of sample (peak maximum).

HOMO = 4.8-E ferrocene (peak to peak average) + E oxidation of sample (peak maximum).

A typical SWV experiment runs at 15 Hz frequency; 25 mV amplitude and 0.004 V increment steps. Results are calculated from 3 freshly spun film samples for both the HOMO and LUMO data.

Absorption spectra were measured using a Cary 5000 UV-VIS-NIR Spectrometer. Measurements were taken from 175 nm to 3300 nm using a PbSmart ['HR detector for extended photometric range with variable slit widths (down to 0.01 nm) for optimum control over data resolution.

-40 -Unless stated otherwise, absorption values are of a solution. Absorption data are obtained by measuring the intensity of transmitted radiation through a solution sample. Absorption intensity is plotted vs. incident wavelength to generate an absorption spectrum. A method for measuring absorption may comprise measuring a 15 mg / ml solution in a quartz cuvette and comparing to a cuvette containing the solvent only.

Unless stated otherwise solution absorption data as provided herein is as measured in toluene solution.

Materials data With reference to Table 1. Compound Example 1 has a longer peak absorption _to wavelength than Comparative Compound 1.

Table 1

Compound Film HOMO (eV) Film Film Solution absorption A (mu) LUMO (eV) absorption k (urn) Comparative Compound 1 -5.26 -4.23 1150 954 Compound Example 1 -5.45 -4.27 1304 1035

ON NC " C6H13 *

NC * S ON W \ *

ON

5* * 0

S

C6H13NC ON C6H13 04H9

ON

C4H9 C6H13 Comparative Compound 1 -41 -With reference to Figure 2, Compound Example 1 has higher absorption intensity than Comparative Compound 1 under the same absorption conditions.

With reference to Figure 3 and as shown in Table 1, a film of Compound Example 1, formed by spin-coating from o-dichlorobenzene, absorbs at about 1300 am which is around 150 nm longer than a film of Comparative Compound 1 formed by spin-coating from toluene,

Device Example 1

A glass substrate coated with a 150 nm thick layer of indium-tin oxide (ITO) was coated with a 0.2 % polyethyleneinaine (PEW) solution in water to form a -5 nm film modifying _to the work function of the ITO. A ca. 500 nm thick bulk heterojunction layer of a mixture of Donor Polymer 1: Compound Example 1 (1: 0.7 by weight) was deposited over the modified ITO layer by bar coating from a 10 mg/m1 solution in an o-dicholorobenzene / butylbenzoate solvent mixture (90:10 v/v). An anode stack of Mo03 (10nm) and ITO (50nm) was formed over the bulk heterojunction by thermal evaporation (Mo03) and 7.5 sputtering ( ITO). \ N,N _ s 0.5

R2= I-Ci2H2s Rb = Donor Polymer 1

Device Example 2

-42 -A device was prepared as described for Device Example 1 except that the solution used to form the bulk heterojunction layer contained fullerene PCBM in addition to Donor Polymer 1 and Compound Example 1 in a weight ratio of Donor Polymer 1: Compound Example 1: PCBM 1: 0.7: 0.3.

Comparative Device 1 A device was prepared as described for Device Example 2 except that Comparative Compound 1 was used in place of Compound Example 1.

With reference to Figure 4, external quantum efficiency peaks at around 1300 nm for Device Example 1. The inclusion of PCBM increases EQE.

With reference to Figure 5, EQE of Comparative Device 2 peaks at about 900 nut With reference to Figure 6, dark currents at a reverse bias of -3V of Device Examples 1 and 2 are much lower than those of Comparative Devices 1 or 2.

Modelling The HOMO and LUMO energy levels of NFAs of formula (I) containing a group of formula (III) and comparative NFAs which do not have a group of formula (III) were modelled. Results arc set out in Table 2 in which in which S if corresponds to oscillator strength of the transition from Si (predicting absorption intensity) and Eopt is the modelled optical gap.

The NEAs containing electron-accepting end-groups of formula (III) have a smaller modelled band gap and longer wavelength modelled optical gap than NFAs containing a comparative electron-accepting end-group.

-43 -

Table 2 Slf

LUMO Eg /eV /n m -3.84 864. . * * * * * ,* * * * * * * Structure

CN

Comparative Model Compound 1 HOMO/ eV -5.28 Eopt /n m 2.95

CN

Comparative Model Compound 2 3.54 -5.22 -3.80 860 0- -0 Comparative Model Compound 3 2.56 -5.66 -4.06 776 0- -0 Comparative Model Compound 4

NC 2.65 -5.27

-3.56 732 -44 -

NC 3.29

Model Compound 1 -5.37 -4.10 979 3.26 Model Compound 2 -5.32 -4.02 952 3.02 Model Compound 3 -5.06 -3.67 894 3.22 Model Compound 4 -5.11 -45 -3.17 -4.15 102 3.48 2.61 Model Compound 9 Model Compound 5 -5.10 3.33 -3.74 911

CN

CM

Model Compound 6 -5.36

NC

Model Compound 7 Model Compound 8 -5.11 -5.01 2.81 -5.38 -3.85 811 -46 -2.81 S s 0- -0 Model Compound 10

Claims

-47 -CLAIMS1. A compound of formula (I) or (II): A1 -(B1)x' -(D1)y' -(B1)x= -A (I) A1 -(B2)x.' -(D2)y2 -(B3)x -A2 -(B3)x4 -(D3)y3 -(B2)x6 -A1 (II) wherein: A2 is a divalent heteroaromatic electron-accepting group; D1, D2 and D3 independently in each occurrence is an electron-donating group; B1, B2, and B3 independently in each occurrence is a bridging group; xl and x= are each independently 0, 1,2 or 3; l and y= y are each independently at least 1; A1 in each occurrence is independently a group of formula (III): -48 -wherein: each R1 is independently a substituent; each R3 is independently H or a substituent; J is C=0, c=s, NRit cRuintc 13 wherein R11 is CN or COOR4° and R4° is H or a substituent and R12 and R13 are each independently CN, CF3 or C00R40; and either each Z1 is N and each Z2 is CR4, or each Z1 is CR4 and each Z2 is N wherein each R4 is independently H or a substituent 2. The compound according to claim I wherein each Z1 is N and each Z2 is CR4. 10 3. The compound according to claim I wherein each Z2 is N and each Z1 is CR4.4. The compound according to any one of the preceding claims wherein each R1 is independently selected from CN, CF3 and COOR4° wherein R4° in each occurrence 5. The compound according to any one of the preceding claims wherein each R3 is an electron-withdrawing group.6. The compound according to claim 5 wherein the electron-withdrawing group is selected from Cl. F, CN, C1_11 fluoroalkyl and COORb wherein Rb is a C1,70 hydrocarhyl grou.7. The compound according to any one of the preceding claims wherein each R4 is independently selected from H or an electron-withdrawing group.8. A composition comprising an electron-donating material and an electron-accepting material wherein the electron accepting material is a compound according to any one of the preceding claims.-49 -An organic electronic device comprising an active layer comprising a compound or composition according to any one of the preceding claims.10. An organic electronic device according to claim 9 wherein the organic electronic device is an organic photorespon sive device comprising a bulk heterojunction layer disposed between an anode and a cathode and wherein the bulk heterojunction layer comprises a composition according to claim S. 11 An organic electronic device according to claim 10 wherein the organic photorespon sive device is an organic photodetector.12. A photosensor comprising a light source and an organic photodetector according to _to claim 11 wherein the organic photodetector is configured to detect light emitted from the light source 13. The photosensor according to claim 12, wherein the light source emits light having a peak wavelength of greater than 900 nm.14. A formulation comprising a compound or composition according to any one of /5 claims 1 to 8 dissolved or dispersed in one or more solvents.15. A method of forming an organic electronic device according to any one of claims 9-11 wherein formation of the active layer comprises deposition of a formulation according to claim 14 onto a surface and evaporation of the one or more solvents.