Abstract: An organic photodetector including an electron blocking layer, where the electron blocking layer prevents and/or reduces dark current by preventing electrons traveling from the organic photodetector's anode to the organic photodetector's photoactive layer during dark, photon-less conditions. The electron blocking layer is formed from a compound having the formula: [M]a+[X]a— (General Formula (I)) where: M is a metal; X is CN, SCN, Se CN or TeCN; and a is at least 1.

Abstract: A polymer comprising a repeating structure of formula (I): -D-X1-A-X2-. D is a conjugated electron-donating group of formula (II); A is a conjugated electron-accepting group; X1 and X2 are each independently a conjugated bridge group selected from phenylene, thiophene, furan, thienothiophene, furofuran, thienofuran, thiazole, oxazole, alkene, alkyne and imine, each of which may be unsubstituted or substituted with one or more substituents. The polymer has a highest occupied molecular orbital (HOMO) level as measured by square wave voltammetry of no more than 5.30 eV from vacuum level. The polymer may be used as an electron donor in an organic photodetector.

Abstract: A composition comprising an electron-donating polymer and an electron acceptor wherein the electron-donating polymer comprises a benzo[1,2-b:4,5-b?]dithiophene repeat unit and wherein a film of the electron-accepting material has a peak absorption wavelength greater than 1000 nm. The composition may be used as a photosensitive layer of an organic photodetector.

Abstract: A material comprising an electron-accepting unit of formula (I): wherein Ar1 and Ar2 independently is a 5- or 6-membered aromatic or heteroaromatic ring or is absent; and each X is independently H or a substituent with the proviso that at least one X is an electron-withdrawing group and wherein X groups bound to adjacent carbon atoms may be linked to form an electron-withdrawing group. The material further comprises an electron-donating unit D comprising a fused or unfused furan or thiophene. The material may be a polymer comprising repeat units of formula (I). The material may be a non-polymeric compound. An organic photodetector may contain a bulk heterojunction layer containing an electron acceptor or an electron donor wherein at least one of the electron acceptor and electron donor contains a unit of formula (I).

Abstract: A composition comprising a first organic electron donor material having an absorption maximum greater than 900 nm; a second organic electron donor material having an absorption maximum at a shorter wavelength than the first organic electron donor material; and an organic electron acceptor material. The composition may be used in an organic photodetector.

Abstract: A formulation comprising an n-type organic semiconductor, a p-type organic semiconductor and a solvent mixture comprising a first solvent and a second solvent wherein the first solvent is an alkylated aromatic hydrocarbon, for example trimethylbenzene, and the second solvent is a benzene substituted with two or more substituents including at least two C1-6 alkoxy groups, for example dimethoxybenzene. The formulation may be used to form the photoactive layer (3) of a photosensitive organic electronic device, for example an organic photo detector, comprising an anode (2) a cathode (4) and the photoactive layer between the anode and the cathode.

Abstract: A formulation comprising an n-type organic semiconductor, a p-type organic semiconductor and a solvent mixture comprising a first solvent and a second solvent wherein the first solvent is an alkylated aromatic hydrocarbon, for example trimethylbenzene, and the second solvent is a benzene substituted with two or more substituents including at least two C1-6 alkoxy groups, for example dimethoxybenzene. The formulation may be used to form the photoactive layer (3) of a photosensitive organic electronic device, for example an organic photo detector, comprising an anode (2) a cathode (4) and the photoactive layer between the anode and the cathode.

Abstract: A composition comprising a first compound and a second compound of formula (I) wherein EDG is an electron-donating group comprising a polycyclic hetero aromatic group and each BAG is an electron-accepting group of formula (II) --- is a bond to EDG; each R10 is, independently in each occurrence, H or a substituent; each R11-R14 is, independently in each occurrence, H or an electron-withdrawing group; and of the first and second compounds of formula (I), the total number of electron-withdrawing groups R11-R14 is greater for the first compound of formula (I). The composition may further contain an electron donor capable of donating an electron to the compounds of formula (I). The composition may be used in the photoactive layer of an organic photodetector.

Abstract: An organic photodetector comprising a first electrode, a second electrode, and a photosensitive organic layer between the electrodes, the photosensitive organic layer comprising a donor polymer and an acceptor compound, characterized in that the acceptor compound has a LUMO level shallower than that of the fullerene derivative PCBM.

Abstract: A compound of formula (I): Each R1 and R2 is, independently in each occurrence, a substituent. Each R3-R10 is, independently in each occurrence, H or a substituent. At least one occurrence of at least one of R11-R14 is CN. Each Y is independently O or S. Z1-Z4 are each independently a direct bond or Z1, Z2, Z3 and/or Z4 together with, respectively, R4 or R5, R7 or R8, R6, or R9 forms an aromatic or heteroaromatic group. The compound of formula (I) may be provided in an active layer of an organic electronic device, e.g. as an electron acceptor in a bulk heterojunction layer of an organic photodetector. A photosensor may comprise the organic photodetector and a light source, e.g. a near infra-red light source.

Abstract: This invention relates to a formulation comprising p-type and n-type organic semiconductors and a solvent mixture comprising an aromatic hydrocarbon substituted with one or more substituents selected from alkyl and alkoxy groups and a unsubstituted or substituted benzothiazole, for example 2-methylbenzothiazole. The formulation may be used to form the photoactive layer (3) of a photosensitive organic electronic device, for example an organic photodetector, comprising an anode (2) a cathode (4) and the photoactive layer between the anode and the cathode.

Abstract: An organic photodetector including an electron blocking layer, where the electron blocking layer prevents and/or reduces dark current by preventing electrons traveling from the organic photodetector's anode to the organic photodetector's photoactive layer during dark, photon-less conditions. The electron blocking layer is formed from a compound having the formula: [M]a+[X]a— (General Formula (I)) where: M is a metal; X is CN, SCN, Se CN or TeCN; and a is at least 1.

Abstract: An organic photodetector (OPD) comprises a microcavity defined by a reflective electrode and a semi-transparent electrode, wherein the microcavity comprises a transparent conductive oxide layer and an active layer comprising an n-type organic semiconductor and a p-type organic semiconductor, and wherein the blend of the n-type organic semiconductor and the p-type organic semiconductor exhibits low absorption at the resonance wavelength, which results in an excellent optical sensitivity in a favorably narrow wavelength region and allows to tune the response to different wavelengths depending on the desired application. In addition, methods of producing such organic photodetectors and methods of tuning the resonance of a microcavity formed in an organic photodetector (OPD) to a predetermined wavelength are provided.

Abstract: An organic photodetector comprising an anode (103), a cathode (107) and a layer (105) comprising an organic electron donor and an organic electron acceptor between the anode and the cathode wherein the weight of the organic electron acceptor is less than 2 times that of the electron donor. The organic electron acceptor may be a fullerene. The organic electron donor may be a conjugated polymer.

Abstract: An organic photodetector comprising an anode; a cathode; and a photosensitive organic layer between the anode and cathode, wherein the photosensitive organic layer comprises an electron donor material and an electron acceptor compound of formula (I): R11 and R12 may be, e.g. C1-20 alkyl and derivatives thereof or an aromatic or heteroaromatic group. R13-R16 may be, e.g. H, F, C1-20 alkyl and derivatives thereof. R20-R23 independently in each occurrence is selected from the group consisting of H, C1-20 alkyl and an electron-withdrawing group. Each X is independently O, S, Se or Te.

Abstract: An organic photodetector comprising a photosensitive organic layer comprising an electron donor and an electron acceptor wherein the electron acceptor is a compound of formula (I): EAG-EDG-EAG??(I) wherein each EAG is an electron accepting group; and EDG is an electron-donating group of formula (II) or (III): A photosensor may comprise the organic photodetector and a light source, e.g. a near infra-red light source.

Abstract: An organic photodetector comprising a first electrode, a second electrode, and a photosensitive organic layer between the electrodes, the photosensitive organic layer comprising a donor polymer and an acceptor compound, characterized in that the acceptor compound has a LUMO level shallower than that of the fullerene derivative PCBM.

Abstract: A gas sensor includes first and second electrodes (107, 109) and a first semiconductor layer (113) comprising a semiconducting transition halide or pseudohalide, for example copper thiocyanate, in electrical contact with the first and second electrodes. The semiconducting transition metal halide or pseudohalide provide that a semiconductor based gas sensor is sensitive to alkenes and can detect low concentrations of alkenes. Furthermore, the gas sensor may comprise a second semiconductor layer (111), different from the first semiconductor layer. The second semiconductor layer is preferably an organic semiconductor. The gas sensor may be a top-gate or bottom-gate thin film transistor (103: gate electrode; 105: gate dielectric) or a horizontal or vertical chemiresistor. The gas sensor may be used for detection of alkenes, for example ethylene or 1-MCP.

Abstract: An organic photodetector comprising an anode (103), a cathode (107) and a layer (105) comprising an organic electron donor and an organic electron acceptor between the anode and the cathode wherein the weight of the organic electron acceptor is less than 2 times that of the electron donor. The organic electron acceptor may be a fullerene. The organic electron donor may be a conjugated polymer.

Abstract: A gas sensor system is made up of a first gas sensor that is sensitive to both a target gas (200) and a secondary gas and a second sensor (300) that is only sensitive to the target gas. The response of the two gas sensors is processed to detect a presence of or a concentration of the target gas. The first sensor includes a semiconductor material that is sensitive to the presence of both the target and the secondary gas and electrodes that are sensitive to the presence of the target gas. The second sensor includes a semiconductor material that is sensitive to the presence of both the target and the secondary gas, but also includes a blocking layer on a surface of at least one of the electrodes that prevents the second gas interacting with the electrodes.