The large-scale artificial synaptic device arrays based on the organic molecule-nanowire heterojunctions with tunable photoconductivity are proposed and demonstrated. The organic thin films of p-type 2,7-dioctyl[1]benzothieno[3,2-b][1] benzothiophene (C8-BTBT) or n-type phenyl-C61-butyric acid methyl ester (PC61BM) are used to wrap the InGaAs nanowire parallel arrays to configure two different type-I heterojunctions, respectively. Due to the difference in carrier injection, persistent negative photoconductivity (NPC) or positive photoconductivity (PPC) are achieved in these heterojunctions. The irradiation with different wavelengths (solar-blind to visible ranges) can stimulate the heterojunction devices, effectively mimicking the synaptic behaviors with two different photoconductivities. Evidently, these photosynaptic devices are illustrated with retina-like behaviors and capabilities for large-area integration, which reveals their promising potential for artificial visual systems.

A perovskite photodiode includes a first electrode and a second electrode, a perovskite photoelectric conversion layer between the first electrode and the second electrode and including a Pb-free perovskite represented by Chemical Formula 1, and an auxiliary layer between the first electrode and the perovskite photoelectric conversion layer and including an organic compound represented by Chemical Formula 2.

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A perovskite photodiode includes a first electrode and a second electrode, a perovskite photoelectric conversion layer between the first electrode and the second electrode and including a Pb-free perovskite represented by Chemical Formula 1, and an auxiliary layer between the first electrode and the perovskite photoelectric conversion layer and including an organic compound represented by Chemical Formula 2.

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A two-dimensional organic/inorganic heterojunction photodetector and a preparation method thereof belongs to the technical field of photoelectric devices. A few layers of two-dimensional materials are transferred to a substrate as a base material by a mechanical peeling method. A few layers of two-dimensional alloy materials are transferred to one side of the two-dimensional materials on the base material by polydimethylsiloxane (PDMS). Then, the base material is put into a tube furnace. A single organic molecular layer is epitaxially grown on the two-dimensional alloy material by controlling the heating temperature and time to form a heterojunction. Finally, a gold thin film is transferred to the organic molecular layer, so that a photodetector is manufactured. The heterojunctions formed by Van der Waals have fewer defects, which can enhance light absorption without causing carrier capture, enabling photodetectors possesses excellent detection capability, large light absorption, and enhanced photoconductivity.

A two-dimensional organic/inorganic heterojunction photodetector and a preparation method thereof belongs to the technical field of photoelectric devices. A few layers of two-dimensional materials are transferred to a substrate as a base material by a mechanical peeling method. A few layers of two-dimensional alloy materials are transferred to one side of the two-dimensional materials on the base material by polydimethylsiloxane (PDMS). Then, the base material is put into a tube furnace. A single organic molecular layer is epitaxially grown on the two-dimensional alloy material by controlling the heating temperature and time to form a heterojunction. Finally, a gold thin film is transferred to the organic molecular layer, so that a photodetector is manufactured. The heterojunctions formed by Van der Waals have fewer defects, which can enhance light absorption without causing carrier capture, enabling photodetectors possesses excellent detection capability, large light absorption, and enhanced photoconductivity.

The present invention provides a photoelectric conversion element which exhibits low electric field strength dependence of a response speed in a case of receiving blue and green light. In addition, the present invention provides an imaging element, an optical sensor, and a compound, which are related to the photoelectric conversion element. The photoelectric conversion element of the present invention includes, in the following order, a conductive film, a photoelectric conversion film, and a transparent conductive film, in which the photoelectric conversion film contains a compound represented by Formula (1). In Formula (1), D represents a group represented by any of Formula (2) to Formula (6).

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A photoelectric conversion element having a first electrode, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a second electrode laminated in this order. The photoelectric conversion layer contains a perovskite compound. The hole transport layer includes a p-type metal oxide semiconductor layer and a hole transport material layer that contains a compound represented by Chemical Formula (I):

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wherein Ar.sup.1 includes an aromatic ring, which may contain a heteroatom, and Ar.sup.1 may have a substituent other than -L.sup.1-X.sup.1. n is an integer of 1 or more. When n is 2 or more, structures represented by -L.sup.1-X.sup.1 may be the same as or different from each other. L.sup.1 is a divalent linking group bonding Ar.sup.1 to X.sup.1 or a single bond. X.sup.1 is a group capable of forming a chemical bond or a hydrogen bond with the p-type metal oxide semiconductor.

A photoelectric conversion element having a first electrode, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a second electrode laminated in this order. The photoelectric conversion layer contains a perovskite compound. The hole transport layer includes a p-type metal oxide semiconductor layer and a hole transport material layer that contains a compound represented by Chemical Formula (I):

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wherein Ar.sup.1 includes an aromatic ring, which may contain a heteroatom, and Ar.sup.1 may have a substituent other than -L.sup.1-X.sup.1. n is an integer of 1 or more. When n is 2 or more, structures represented by -L.sup.1-X.sup.1 may be the same as or different from each other. L.sup.1 is a divalent linking group bonding Ar.sup.1 to X.sup.1 or a single bond. X.sup.1 is a group capable of forming a chemical bond or a hydrogen bond with the p-type metal oxide semiconductor.

A photo-capacitance sensor includes an input surface and one or more light sources arranged to illuminate a portion of the input surface. The photo-capacitance sensor also includes an array of photo-capacitors arranged to receive light from the one or more light sources which is reflected from an object in contact with, or proximate to, the illuminated portion of the input surface. The array of photo-capacitors is configured for detecting a reflective pattern of the object.

A photoelectric conversion element includes a first electrode, a first interfacial layer, a photoelectric conversion layer, and a second electrode in this order, wherein the photoelectric conversion layer includes quantum dots and a first organic compound, the first organic compound satisfies Formula (1), an electron affinity of a material used for the first interfacial layer, an electron affinity of the quantum dots, and an electron affinity of the first organic compound satisfy Formulas (2) and (3):
E2>E1(1) E1 [eV]: energy at short-wavelength end of optical wavelength region detected by the photoelectric conversion element E2 [eV]: band gap of the first organic compound
E3<E40.2(2)
E40.4<E5<E4(3) E3 [eV]: electron affinity of material used for the first interfacial layer E4 [eV]: electron affinity of the quantum dots E5 [eV]: electron affinity of the first organic compound.