A photovoltaic device includes an organic semiconductor and an inorganic semiconductor. The organic semiconductor includes a photoactive region that generates excitons. The inorganic semiconductor has piezoelectricity and includes a dissociation region for dissociating carriers included in the excitons. A relationship of energy levels between the photoactive region and the dissociation region satisfies at least one equation E.sub.LUMO>E.sub.C or equation E.sub.HOMO<E.sub.V.

There are provided a photodetection element including a first electrode layer 11, a second electrode layer 12, a photoelectric conversion layer 13 provided between the first electrode layer 11 and the second electrode layer 12, an electron transport layer 21 provided between the first electrode layer 11 and the photoelectric conversion layer 13, and a hole transport layer 22 provided between the photoelectric conversion layer 13 and the second electrode layer 12, in which the photoelectric conversion layer 13 contains quantum dots of a compound semiconductor containing an Ag element and a Bi element, and the hole transport layer 22 contains an organic semiconductor A including a predetermined structure, and are provided an image sensor.

Photodiodes configured to convert incident photons in the short-wave infrared (SWIR) to electric current, where the photodiodes have a PbS/PbCl.sub.x core/shell nanocrystal absorber layer. The PbCl.sub.x shell in the PbS/PbCl.sub.x nanocrystals provide native passivation in the (100) crystal facets and enable removal of native ligands and ligand exchange on the (111) crystal facets of the PbS/PbCl.sub.x nanocrystals such that the photodiode exhibits reduced current densities under reverse bias and greater infrared photoresponse, providing improved device performance as compared to photodiodes having absorber layers formed from PbS core nanocrystals alone.

The present invention pertains to a light absorption layer for forming a photoelectric conversion element and a solar cell having an excellent photoelectric conversion efficiency, and a photoelectric conversion element and a solar cell having the light absorption layer. This light absorption layer contains a perovskite compound and quantum dots, and the quantum dots have a circularity of 0.50 to 0.92. The present invention is a light absorption layer, a photoelectric conversion element, and a solar cell containing a perovskite compound and quantum dots, wherein the particle shape of the quantum dots is controlled, the surface of the quantum dots is covered by a compound having a specific energy level, or the above features are combined, whereby it is made possible to obtain a light absorption layer, a photoelectric conversion element, and a solar cell having an excellent photoelectric conversion efficiency.

Graphene photodetectors capable of operating in the sub-bandgap region relative to the bandgap of semiconductor nanoparticles, as well as methods of manufacturing the same, are provided. A photodetector can include a layer of graphene, a layer of semiconductor nanoparticles, a dielectric layer, a supporting medium, and a packaging layer. The semiconductor nanoparticles can be semiconductors with bandgaps larger than the energy of photons meant to be detected.

Various perovskite solar cell embodiments include a flexible metal substrate (e.g., including a metal doped TiO.sub.2 layer), a perovskite layer, and a transparent electrode layer (e.g., including a dielectric/metal/dielectric structure), wherein the perovskite layer is provided between the flexible metal substrate and the transparent electrode layer. Also, various tandem solar cell embodiments including a perovskite solar cell and either a quantum dot solar cell, and organic solar cell or a thin film solar cell.

Various perovskite solar cell embodiments include a flexible metal substrate (e.g., including a metal doped TiO.sub.2 layer), a perovskite layer, and a transparent electrode layer (e.g., including a dielectric/metal/dielectric structure), wherein the perovskite layer is provided between the flexible metal substrate and the transparent electrode layer. Also, various tandem solar cell embodiments including a perovskite solar cell and either a quantum dot solar cell, and organic solar cell or a thin film solar cell.

Disclosed is a preparation method for crosslinked nanoparticle film. The preparation method comprises: dispersing nanoparticles in a solvent and uniformly mixing same, so as to obtain a nanoparticle solution; and using the nanoparticle solution to prepare a nanoparticle thin film by means of a solution method, and introducing a gas combination to promote a crosslinking reaction, so as to obtain a crosslinked nanoparticle thin film. By introducing a gas combination during film formation of nanoparticles, the present disclosure promotes the crosslinking among particles, and thus increases the electrical coupling among particles, lowers the potential barrier of carrier transmission, and increases the carrier mobility, thereby greatly improving the electrical properties of the thin film.

An optical sensor includes: a photosensitive layer that absorbs incident light to generate a first carrier with a first polarity and a second carrier with a second polarity different from the first polarity; a channel layer that is electrically connected to the photosensitive layer and that conducts the first carrier that has moved from the photosensitive layer; a counter electrode facing the channel layer through the photosensitive layer; an insulating layer positioned between the photosensitive layer and the counter electrode; and a source electrode and a drain electrode each electrically connected to the channel layer.

An optical sensor includes: a photosensitive layer that absorbs incident light to generate a first carrier with a first polarity and a second carrier with a second polarity different from the first polarity; a channel layer that is electrically connected to the photosensitive layer and that conducts the first carrier that has moved from the photosensitive layer; a counter electrode facing the channel layer through the photosensitive layer; an insulating layer positioned between the photosensitive layer and the counter electrode; and a source electrode and a drain electrode each electrically connected to the channel layer.