Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/615—Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
  • H10K85/621—Aromatic anhydride or imide compounds, e.g. perylene tetra-carboxylic dianhydride or perylene tetracarboxylic di-imide
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/60—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation in which radiation controls flow of current through the devices, e.g. photoresistors
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/20—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising organic-organic junctions, e.g. donor-acceptor junctions
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
  • H10K30/30—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/10—Organic polymers or oligomers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/10—Organic polymers or oligomers
  • H10K85/111—Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
  • H10K85/113—Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/615—Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
  • H10K85/626—Polycyclic condensed aromatic hydrocarbons, e.g. anthracene containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/649—Aromatic compounds comprising a hetero atom
  • H10K85/653—Aromatic compounds comprising a hetero atom comprising only oxygen as heteroatom
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/649—Aromatic compounds comprising a hetero atom
  • H10K85/655—Aromatic compounds comprising a hetero atom comprising only sulfur as heteroatom
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/649—Aromatic compounds comprising a hetero atom
  • H10K85/657—Polycyclic condensed heteroaromatic hydrocarbons
  • H10K85/6574—Polycyclic condensed heteroaromatic hydrocarbons comprising only oxygen in the heteroaromatic polycondensed ring system, e.g. cumarine dyes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/649—Aromatic compounds comprising a hetero atom
  • H10K85/657—Polycyclic condensed heteroaromatic hydrocarbons
  • H10K85/6576—Polycyclic condensed heteroaromatic hydrocarbons comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy
  • Y02E10/549—Organic PV cells

Definitions

• Embodiments of the present disclosure relate to organic photodetectors.
• organic electronic devices comprising organic semiconductor materials are known, including organic light-emitting devices, organic field effect transistors, organic photovoltaic devices and organic photodetectors (OPDs).
• organic light-emitting devices including organic light-emitting devices, organic field effect transistors, organic photovoltaic devices and organic photodetectors (OPDs).
• OPDs organic photodetectors
• WO 2018/065352 discloses an OPD having a photoactive layer that contains a small molecule acceptor which does not contain a fullerene moiety and a conjugated copolymer electron donor having donor and acceptor units.
• WO 2018/065356 discloses an OPD having a photoactive layer that contains a small molecule acceptor which does not contain a fullerene moiety and a conjugated copolymer electron donor having randomly distributed donor and acceptor units.
• Embodiments of the present disclosure provide an organic photodetector comprising: an anode; a cathode; and a photosensitive organic layer disposed between the anode and cathode.
• the photosensitive organic layer comprises an electron donor and an electron acceptor.
• the electron acceptor is a compound of formula (I):
• each EAG is an electron accepting group
• EDG is an electron-donating group of formula (II) or (III):
• each X is independently O or S;
• Ar 3 and Ar 4 independently in each occurrence is a monocyclic or polycyclic aromatic or heteroaromatic group
• Ar 5 is selected from the group consisting of thiophene, furan and benzene which is unsubstituted or substituted with one or two substituents;
• R and R independently in each occurrence is a substituent
• R 4 and R 5 are each independently H or a substituent
• R 3 and R 6 are each independently H, a substituent or a divalent group bound to EAG;
• Z 1 is a direct bond or Z 1 together with the substituent R 4 forms Ar 1 wherein Ar 1 is a monocyclic or polycyclic aromatic or heteroaromatic group;
• Z is a direct bond or Z together with the substituent R forms Ar wherein Ar is a monocyclic or polycyclic aromatic or heteroaromatic group; p is 1, 2 or 3; q is 1, 2 or 3; and
• a circuit comprising an organic photodetector as described herein, and at least one of a voltage source for applying a reverse bias to the organic photodetector and a device configured to measure photocurrent generated by the photodetector.
• an organic photodetector as described herein comprising formation of the photosensitive organic layer over one of the anode and cathode and formation of the other of the anode and cathode over the photosensitive organic layer.
• compounds of formula (I) may be capable of absorbing light at long wavelengths, e.g. greater than 750 nm, optionally greater than 1000 nm, optionally less than 1500 nm, allowing for use of these compounds in organic photodetectors, particularly in a photosensor containing such an OPD and a near infra red light source.
• a photosensor comprising a light source and an organic photodetector as described herein configured to detect light emitted from the light source.
• a method of determining the presence and / or concentration of a target material in a sample comprising illuminating the sample and measuring a response of an organic photodetector as described herein which is configured to receive light emitted from the sample upon illumination.
• FIG. 1 illustrates an organic photodetector according to an embodiment of the invention.
• Figure 2 is graphs of external quantum efficiency vs. voltage for an OPD according to some embodiments of the present disclosure in which the acceptor is a compound of formula (I) and a comparative OPD in which the acceptor is IEICO-4F.
• 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.
• 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.”
• the terms “connected,” “coupled,” or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, electromagnetic, or a combination thereof.
• 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.
• 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 the items in the list, and any combination of the items in the list.
• Figure 1 illustrates an OPD according to some embodiments of the present disclosure.
• the OPD comprises a cathode 103, an anode 107 and a bulk heterojunction layer 105 disposed between the anode and the cathode.
• the OPD may be supported on a substrate 101, optionally a glass or plastic substrate.
• 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 and the substrate.
• the bulk heterojunction layer comprises a mixture of an electron acceptor and an electron donor.
• the bulk heterojunction layer consists of the electron acceptor and the electron donor.
• the bulk heterojunction layer comprises a further electron acceptor other than the electron acceptor of formula (I).
• the further electron acceptor is a fullerene.
• Each of the anode and cathode may independently be a single conductive layer or may comprise a plurality of layers.
• the OPD may comprise layers other than the anode, cathode and bulk shown in Figure 1.
• a hole-transporting layer is disposed between the anode and the bulk heterojunction layer.
• an electron-transporting layer is disposed between the cathode and the bulk heterojunction layer.
• 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 photodetectors as described in this disclosure may be 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 photodetectors may be variable.
• the photodetector may be continuously biased when in use.
• a photodetector system comprises a plurality of photodetectors as described herein, such as an image sensor of a camera.
• 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.
• the light from the light source may or may not be changed before reaching the OPD.
• the light may be filtered, down-converted or up- converted before it reaches the OPD.
• the light source has a peak wavelength of greater than 750 nm, optionally less than 1500 nm.
• the bulk heterojunction layer may contain an electron acceptor (n-type) compound of formula (I):
• each EAG is an electron accepting group
• EDG is an electron-donating group of formula (II) or (III):
• each X is independently O or S;
• Ar 3 and Ar 4 independently in each occurrence is a monocyclic or polycyclic aromatic or heteroaromatic group;
• Ar 5 is selected from the group consisting of thiophene, furan and benzene which is unsubstituted or substituted with one or two substituents; R 1 and R 2 independently in each occurrence is a substituent;
• R 4 and R 5 are each independently H or a substituent
• R 3 and R 6 are each independently H, a substituent or a divalent group bound to EAG;
• Z 1 is a direct bond or Z 1 together with the substituent R 4 forms Ar 1 wherein Ar 1 is a monocyclic or polycyclic aromatic or heteroaromatic group
• Z 2 is a direct bond or Z 2 together with the substituent R 5 forms Ar 2 wherein Ar 2 is a monocyclic or polycyclic aromatic or heteroaromatic group
• p is 1, 2 or 3
• q is 1, 2 or 3;
• R 1 and R 2 of formula (la) or (lb) independently in each occurrence are selected from the group consisting of: linear, branched or cyclic Ci-20 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced by O, S, NR , CO or COO wherein R is a Ci-nhydrocarbyl and one or more H atoms of the Ci_2o alkyl may be replaced with F; and a group of formula (Ak)u-(Ar 6 )v wherein Ak is a Ci-12 alkylene chain in which one or more C atoms may be replaced with O, S, CO or COO; u is 0 or 1; Ar 6 in each occurrence is independently an aromatic or hetero aromatic group which is unsubstituted or substituted with one or more substituents; and v is at least 1, optionally 1, 2 or 3.
• Ci_i2hydrocarbyl may be Ci-12 alkyl; unsubstituted phenyl; and phenyl substituted with one or more Ci_ 6 alkyl groups.
• Ar 6 is preferably phenyl.
• substituents of Ar 6 may be a substituent R 16 wherein R 16 in each occurrence is independently selected from Ci_ 2 o alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced by O, S, NR , CO or COO and one or more H atoms of the Ci- 20 alkyl may be replaced with F.
• -(Ar 6 )v may be a linear or branched chain of Ar 6 groups.
• a linear chain of Ar groups as described herein has only on monovalent terminal Ar 6 group whereas a branched chain of Ar 6 groups has at least two monovalent terminal Ar 6 groups.
• at least one of R 1 and R 2 in each occurrence is phenyl which is unsubstituted or substituted with one or more substituents selected from R 16 as described above..
• each R 3 -R 6 is independently selected from:
• Ci- 12 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO; and an aromatic or heteroaromatic group Ar 6 which is unsubstituted or substituted with one or more substituents.
• Ar 6 is preferably an aromatic group, more preferably phenyl.
• the one or more substituents of Ar 6 may be selected from Ci- 12 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO.
• non-terminal C atom of an alkyl group as used herein is meant a C atom of the alkyl other than the methyl C atom of a linear (n-alkyl) chain or the methyl C atoms of a branched alkyl chain.
• Ar 3 and Ar 4 are each independently selected from thiophene, furan, bifuran and bithiophene.
• Ar 3 , Ar 4 and Ar 5 are each independently unsubstituted or substituted with one or more substituents.
• Preferred substituents of Ar 3 , Ar 4 and Ar 5 are selected from groups R 3 -R 6 described above other than H, preferably Ci_ 2 o alkyl wherein one or more non-adjacent, non-terminal C atoms are replaced with O, S, CO or COO.
• EDG is selected from formulae (Ila) and (Ilia):
• EDG is selected from formulae (lib) and (Illb): wherein R in each occurrence is independently H or a substituent.
• R in each occurrence is independently selected from:
• Ci- 12 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO; and an aromatic or heteroaromatic group Ar 6 which is unsubstituted or substituted with one or more substituents.
• each R 3 -R 6 and, if present, R 7 is H; Ci- 20 alkyl; or Ci- 20 alkoxy.
• At least one of, optionally both of, R 4 and R 5 is not H, and each R 3 , R 6 and, if present, R 7 is H.
• at least one of p and q is 2.
• Z 1 is linked to R 4 to form a monocyclic aromatic or hetero aromatic group and / or Z 2 is linked to R 5 to form a monocyclic aromatic or heteroaromatic group.
• Z is linked to R to form a thiophene ring or furan ring and / or Z is linked to R 5 to form a thiophene ring or furan ring.
• Each EAG has a LUMO level that is deeper (i.e. further from vacuum) than that of EDG, preferably at least 1 eV deeper.
• the LUMO levels of EAG and EDG may be as determined by modelling the LUMO level of EAG-H with that of H-EDG-H, i.e. by replacing the bonds between EAG and EDG with bonds to a hydrogen atom. Modelling may be performed using Gaussian09 software available from Gaussian using
• Gaussian09 with B3LYP (functional) and LACVP* (Basis set).
• each EAG is a group of formula (IV) or (V):
• A is a 5- or 6-membered ring which is unsubstituted or substituted with one or more substituents; R 10 and R 11 independently in each occurrence is a substituent; and
• Ar is an aromatic or heteroaromatic group which is unsubstituted or substituted with one or more substituents.
• each EAG is a group of formula (VI): wherein:
• R 10 in each occurrence is H or a substituent; — represents a linking position to EDG; and each X 1 -X4 is independently CR 13 or N wherein R 13 in each occurrence is H or a substituent.
• each R 13 is independently selected from H; C M2 alkyl; and an electron withdrawing group.
• the electron withdrawing group is F or CN.
• R 10 is preferably H.
• Substituents R 10 are preferably selected from the group consisting of C ⁇ . ⁇ 2 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO and one or more H atoms of the alkyl may be replaced with F; and an aromatic group Ar 9 , optionally phenyl, which is unsubstituted or substituted with one or more substituents selected from F and C 1-12 alkyl wherein one or more non-adjacent, non terminal C atoms may be replaced with O, S, COO or CO.
• R 3 and / or R 6 is B(R 14 ) 2 wherein R 14 in each occurrence is a substituent, optionally a Ci_ 2 ohydrocarbyl group, and one or both EAG groups is an unsubstituted or substituted heteroaromatic group of formula (VII): wherein Ar is a monocyclic or fused hetero aromatic group which is unsubstituted or substituted with one or more substituents; is a bond to the boron atom of R 3 or R 6 ; and— is the bond to EDG.
• R 14 in each occurrence is a substituent, optionally a Ci_ 2 ohydrocarbyl group, and one or both EAG groups is an unsubstituted or substituted heteroaromatic group of formula (VII): wherein Ar is a monocyclic or fused hetero aromatic group which is unsubstituted or substituted with one or more substituents; is a bond to the boron atom of R 3 or R 6 ; and— is
• The, or each, substituent of Ar may be selected from substituents described with reference to R .
• R 14 is a Ci_ 2 ohydrocarbyl group
• R 14 is selected from Ci- 12 alkyl
• the group of formula (VII) is selected from formulae (Vila), (Vllb) and (Vile):
• R 15 in each occurrence is independently H or a substituent, optionally H or a substituent as described with reference to R 7.
• EDG, EAG and the B(R 14 ) 2 substituent of EDG may be linked together to form a 5- or 6-membered ring.
• EAG is selected from formulae (XIV)-(XXV): J is O or S.
• A is a 5- or 6-membered ring which is unsubstituted or substituted with one or more substituents and which may be fused to one or more further rings.
• R in each occurrence is a substituent, optionally Ci- 12 alkyl wherein one or more non- adjacent, non-terminal C atoms may be replaced with O, S, COO or CO and one or more H atoms of the alkyl may be replaced with F.
• R in each occurrence is independently H; F; Ci- 12 alkyl wherein one or more non- adjacent, non-terminal C atoms may be replaced with O, S, COO or CO and one or more H atoms of the alkyl may be replaced with F; or an aromatic group Ar , optionally phenyl, which is unsubstituted or substituted with one or more substituents selected from F and Ci- 12 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO.
• R 26 is a substituent, preferably a substituent selected from: -(Ar 13 ) w wherein Ar 13 in each occurrence is independently an unsubstituted or substituted aryl or heteroaryl group, preferably thiophene, and w is 1, 2 or 3; C M 2 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO and one or more H atoms of the alkyl may be replaced with F.
• Ar 14 is a 5-membered heteroaromatic group, preferably thiophene or furan, which is unsubstituted or substituted with one or more substituents.
• Substituents of Ar 13 and Ar 14 are optionally selected from C ⁇ - ⁇ i alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, COO or CO and one or more H atoms of the alkyl may be replaced with F.
• Z 1 is N or P T 1 , T2 and T 3 each independently represent an aryl or a heteroaryl ring which may be fused to one or more further rings. Substituents of T 1 , T2 and T 3 , where present, are optionally selected from non-H groups of R 15 .
• Exemplary compounds of formula (XIYa) or (XIYb) include:
• Ak is a Ci- 12 alkylene chain in which one or more C atoms may be replaced with O, S, CO or COO;
• An is an anion, optionally -SO 3 ; and each benzene ring is independently unsubstitued or substituted with one or more substituents selected from substituents described with reference to R 10 .
• Exemplary EAGs of formula (XXI) are:
• An exemplary EAG group of formula (XXII) is:
• EH is ethylhexyl
• the compound of formula (I) may be used in combination with a fullerene acceptor.
• the compound of formula (I) : 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.
• the fullerene may be a C6o, C70, C76, C78 or Cg4 fullerene or a derivative thereof including, without limitation, PCBM-type fullerene derivatives (including phenyl-C61- butyric acid methyl ester (CgoPCBM) and phenyl-C71 -butyric acid methyl ester (C / oPCBM)), TCBM-type fullerene derivatives (e.g. tolyl-C61 -butyric acid methyl ester (C60TCBM)), and ThCBM-type fullerene derivatives (e.g. thienyl-C61 -butyric acid methyl ester (CeoThCBM)
• PCBM-type fullerene derivatives including phenyl-C61- butyric acid methyl ester (CgoPCBM) and phenyl-C71 -butyric acid methyl ester (C / oPCBM)
• a fullerene acceptor may have formula (VIII):
• 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 (Ilia), (Mb) and (IIIc): wherein R 30 -R 42 are each independently H or a substituent.
• Substituents R 30 -R 42 are optionally and independently in each occurrence selected from the group consisting of aryl or heteroaryl, optionally phenyl, which may be
• Ci- 20 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, CO or COO and one or more H atoms may be replaced with F.
• Substituents of aryl or heteroaryl groups R 30 -R 42 are optionally selected from Ci- 12 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, CO or COO and one or more H atoms may be replaced with F.
• the donor (p-type) compound is not particularly limited and may be appropriately selected from electron donating materials that are known to the person skilled in the art, including organic polymers and non-polymeric organic molecules.
• the p-type compound has a HOMO deeper (further from vacuum) than a LUMO of the compound of formula (I).
• the gap between the HOMO level of the p-type donor and the LUMO level of the n-type acceptor compound of formula (I) is less than 1.4 eV.
• the p-type donor compound is an organic conjugated polymer, which can be a homopolymer or copolymer including alternating, random or block copolymers. Preferred are non-crystalline or semi- crystalline conjugated organic polymers.
• the p-type organic semiconductor 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 eV.
• polymers selected 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),
• Preferred examples of p-type donors are copolymers of polyfluorenes and polythiophenes, each of which may be substituted, and polymers comprising benzothiadiazole-based and thiophene-based repeating units, each of which may be substituted. It is understood that the p-type donor may also consist of a mixture of a plurality of electron donating materials.
• the donor polymer comprises a repeat unit of formula (XXX):
• R 50 and R 51 independently in each occurrence is H or a substituent.
• R 50 and R 51 may be selected from groups other than H described with respect to R 7 .
• each R 50 is a substituent.
• the R 50 groups are linked to form a group of formula -Y ⁇ R 52 ) ! - wherein Y 1 is O, NR 53 , or C(R 52 )2; R 52 in each occurrence is H or a substituent, preferably a substituent as described with reference to R 1 , most preferably a Ci_ 3 ohydrocarbyl group; and R 53 is a substituent, preferably a Ci_ 3 ohydrocarbyl group.
• each R 51 is H.
• the donor polymer comprises a repeat unit selected from repeat units of formulae:
• R 25 , Z 1 , R 23 and R 25 are as described above.
• Exemplary donor materials are disclosed in, for example, WO2013/051676, the contents of which are incorporated herein by reference.
• the p-type donor has a HOMO level no more than 5.5 eV from vacuum level.
• the p-type donor has a HOMO level at least 4.1 eV from vacuum level.
• HOMO and LUMO levels of a compound as described herein are as measured from a film of the compound using square wave voltammetry.
• the weight of the donor compound to the acceptor compound is from about 1:0.5 to about 1:2.
• the weight ratio of the donor compound to the acceptor compound is about 1:1 or about 1:1.5.
• At least one of the first and second electrodes is transparent so that light incident on the device may reach the bulk heterojunction layer. In some embodiments, both of the first and second electrodes are transparent. Each transparent electrode preferably has a transmittance of at least 70 %, optionally at least 80 %, to wavelengths in the range of 300-900 nm.
• one electrode is transparent and the other electrode is reflective.
• the transparent electrode comprises or consists of a layer of transparent conducting oxide, preferably indium tin oxide or indium zinc oxide.
• the electrode may comprise poly 3,4-ethylenedioxythiophene (PEDOT).
• the electrode may comprise a mixture of PEDOT and polystyrene sulfonate (PSS).
• PSS polystyrene sulfonate
• the electrode may consist of a layer of PEDOT:PSS.
• the reflective electrode may comprise a layer of a reflective metal.
• the layer of reflective material may be aluminium or silver or gold.
• a bi-layer electrode may be used.
• the electrode may be an indium tin oxide (ITO)/silver bi-layer, an ITO/aluminium bi-layer or an ITO/gold bi-layer.
• ITO indium tin oxide
• the device may be formed by forming the bulk heterojunction layer over one of the anode and cathode supported by a substrate and depositing the other of the anode or cathode over the bulk heterojunction layer.
• the area of the OPD may be less than about 3 cm , less than about 2 cm , less than about 1 cm 2 , less than about 0.75 cm 2 , less than about 0.5 cm 2 or less than about
• the substrate may be, without limitation, a glass or plastic substrate.
• the substrate can be described as an inorganic semiconductor.
• the substrate may be silicon.
• 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 substrate supporting one of the anode and cathode may or may not be transparent if, in use, incident light is to be transmitted through the other of the anode and cathode.
• the bulk heterojunction layer may be formed by any process including, without limitation, thermal evaporation and solution deposition methods.
• the bulk heterojunction layer is formed by depositing a formulation comprising the acceptor material and the electron donor material dissolved or dispersed in a solvent or 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 substituted with one or more substituents selected from chlorine, C MO alkyl and Ci- 10 alkoxy wherein two or more substituents may be linked to form a ring which may be unsubstituted or substituted with one or more Ci_ 6 alkyl groups, optionally toluene, xylenes, trimethylbenzenes, tetramethylbenzenes, anisole, indane and its alkyl- substituted derivatives, and tetralin and its alkyl-substituted derivatives.
• substituents selected from chlorine, C MO alkyl and Ci- 10 alkoxy wherein two or more substituents may be linked to form a ring which may be unsubstituted or substituted with one or more Ci_ 6 alkyl groups, optionally toluene, xylenes, trimethylbenzenes, tetramethylbenzenes, anisole, indane and
• 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 C MO alkyl benzoate, benzyl benzoate or dimethoxybenzene.
• a mixture of trimethylbenzene and benzyl benzoate is used as the solvent.
• a mixture of trimethylbenzene and dimethoxybenzene is used as the solvent.
• the formulation may comprise further components in addition to the electron acceptor, the electron donor and the one or more solvents.
• adhesive agents defoaming 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.
• the 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 of the light may be detected, e.g. due to absorption by and / or emission of light from a target material in a sample disposed in a light path between the light source and the organic photodetector.
• the sensor may be, without limitation, a gas sensor, a biosensor, an X- ray imaging device, 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 ID 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 bound thereto. Examples
• a compound may be prepared according to the following reaction scheme:
• the fused thiophene material (which can be made as described in Macromolecular Rapid Communications , 2011, 32, 1664 or Chem. Mater., 2017, 29, 8369) (1 g, 1.0 mmol) was dissolve in THF and cooled to -78 °C under nitrogen. N-Butyllithium (1.65 mL, 4.1 mmol) was added dropwise and the solution stirred for 1 h at -78 °C before tributyltin chloride (0.99 mg, 3.0 mmol) in THF (5 mL) was added dropwise. The reaction mixture was allowed to reach r.t. over 16 h. Methanol was added to quench the reaction and the solvents were removed. The crude material was triturated with methanol several times to yield to stage 2 material which was used in the next step without further purification.
• Stage 1 material (1.3 g, 2.4 mmol) and stage 2 material (1.5 g, 0.97 mmol) was dissolved in toluene and degassed.
• Tn(o-tolyl (phosphine (88 mg, 0.3 mmol) and tris(dibenzylideneacetone) dipalladium (71 mg, 0.08 mmol) were added and the reaction mixture stirred at 80 °C for 5 h.
• the reaction mixture was cooled and passed through a celite plug which was further eluted with toluene.
• the filtrate was concentrated to yield a black semisolid which was triturated with methanol to obtain the crude product as a solid. This was purified by column chromatography on silica using DCM in hexane.
• Quantum chemical modelling was performed using Gaussian09 software available from Gaussian using Gaussian09 with B3LYP (functional) and LACVP* (Basis set).
• Model Compound Examples 1 and 2 have a HOMO which is shallower (i.e. closer to vacuum level) and a smaller band gap than Model Comparative Compounds 1 or 2.
• Device Example 1 Given Reference to Table 1, Model Compound Examples 1 and 2 have a HOMO which is shallower (i.e. closer to vacuum level) and a smaller band gap than Model Comparative Compounds 1 or 2.
• a device having the following structure was prepared:
• a glass substrate coated with a layer of indium-tin oxide (GGO) was treated with polyethyleneimine (PEIE) to modify the work function of the ITO.
• PEIE polyethyleneimine
• a ca. 500 nm thick bulk heterojunction layer of a mixture of Donor Polymer 1 and Compound Example 1 was deposited over the modified ITO layer by bar coating from a 1,2,4 Trimethylbenzene; Dimethoxybenzene 95:5 v/v solvent mixture in a donor : acceptor mass ratio of 1: 1.5.
• An anode (Clevios HIL-E100) available from Heraeus was formed over the donor / acceptor mixture layer by spin-coating.
• a device was prepared as described for Device Example 1 except that Compound Example 1 was replaced with IEICO-4F: With reference to Figure 2, external quantum efficiency of Device Example 1 is higher than that of Comparative Device 1 at wavelengths above about 1000 nm.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Electromagnetism (AREA)
• Light Receiving Elements (AREA)
• Electroluminescent Light Sources (AREA)
• Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
• Plural Heterocyclic Compounds (AREA)
• Photovoltaic Devices (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (2)

Family

ID=65024853

Family Applications (1)

Country Status (7)

Cited By (3)

Families Citing this family (1)

Citations (3)

Family Cites Families (22)

• 2018
  • 2018-11-30 GB GB1819625.3A patent/GB2579418A/en not_active Withdrawn
• 2019
  • 2019-11-29 JP JP2021530135A patent/JP2022509831A/ja active Pending
  • 2019-11-29 CN CN202410373489.0A patent/CN118301954A/zh active Pending
  • 2019-11-29 KR KR1020217020320A patent/KR20210098503A/ko active Pending
  • 2019-11-29 WO PCT/GB2019/053394 patent/WO2020109825A2/en not_active Ceased
  • 2019-11-29 EP EP19816436.0A patent/EP3888151A2/en active Pending
  • 2019-11-29 CN CN201980078486.1A patent/CN113196513A/zh active Pending
• 2020
  • 2020-12-15 US US17/122,797 patent/US12137612B2/en active Active
• 2023
  • 2023-12-01 JP JP2023203780A patent/JP2024037774A/ja active Pending

Patent Citations (3)

Non-Patent Citations (6)

Also Published As

Similar Documents

Legal Events