The present invention provides a method of producing a composite photocatalyst having a remarkable water splitting activity, which is capable of efficiently loading a co-catalyst having a small particle size in a highly dispersed manner on a surface of an optical semiconductor. According to the present invention, the method of producing a composite photocatalyst from a plurality types of optical semiconductors includes a step of heating a solid-liquid mixture containing a solvent, a co-catalyst or a co-catalyst source, and a plurality of types of optical semiconductors by irradiating the solid-liquid mixture with microwave.

Provided is a solar cell comprising a first electrode, a second electrode, a light-absorbing layer located between the first electrode and the second electrode, and an electron transport layer located between the first electrode and the light-absorbing layer. At least one electrode selected from the group consisting of the first electrode and the second electrode has light-transmissive property. The light-absorbing layer contains a perovskite compound represented by a chemical formula ASnX.sub.3 (where A is a monovalent cation and X is a halogen anion). The electron transport layer contains an electron transport material including Ti and Zn. A difference between energy levels of lower ends of conduction bands of the electron transport material and the perovskite compound is less than 0.42 eV.

A dye-sensitized solar cell (100) includes: a first electrode containing first metal oxide particles and including a porous semiconductor layer (16A) carrying dye; a second electrode acting as a counter electrode of the first electrode; and a porous insulating layer (36A) provided between the first electrode and the second electrode, the porous insulating layer (36A)(i) holding an electrolytic solution (42) containing a redox couple and a pyrazole-based compound, and (ii) containing second metal oxide particles.

The invention provides an optoelectronic device comprising a porous material, which porous material comprises a semiconductor comprising a perovskite. The porous material may comprise a porous perovskite. Thus, the porous material may be a perovskite material which is itself porous. Additionally or alternatively, the porous material may comprise a porous dielectric scaffold material, such as alumina, and a coating disposed on a surface thereof, which coating comprises the semiconductor comprising the perovskite. Thus, in some embodiments the porosity arises from the dielectric scaffold rather than from the perovskite itself. The porous material is usually infiltrated by a charge transporting material such as a hole conductor, a liquid electrolyte, or an electron conductor. The invention further provides the use of the porous material as a semiconductor in an optoelectronic device. Further provided is the use of the porous material as a photosensitizing, semiconducting material in an optoelectronic device. The invention additionally provides the use of a layer comprising the porous material as a photoactive layer in an optoelectronic device. Further provided is a photoactive layer for an optoelectronic device, which photoactive layer comprises the porous material.

A solar cell device having a solid state light absorber region that incorporates a donor-acceptor particle structure. The particle structure includes acceptor particles that generate a flow of electrons in the solid state light absorber region in response to absorbed photons; and donor particles comprising a phosphorescent material, wherein each donor particle is coupled to a group of acceptor particles, and wherein the phosphorescent material absorbs high energy photons and emits lower energy photons that are absorbed by the acceptor particles.

In one aspect, nanostructured films are described herein comprising controlled architectures on multiple length scales (e.g. ≥3). As described further herein, the ability to control film properties on multiple length scales enables tailoring structures of the films to specific applications including, but not limited to, optoelectronic, catalytic and photoelectrochemical cell applications. In some embodiments, a nanostructured film comprises a porous inorganic scaffold comprising particles of an electrically insulating inorganic oxide. An electrically conductive metal oxide coating is adhered to the porous inorganic scaffold, wherein the conductive metal oxide coating binds adjacent particles of the insulating inorganic oxide.

Provided is a photoelectric conversion element including: a first electrode; a hole blocking layer; an electron transport layer; a hole transport layer; and a second electrode, wherein the hole blocking layer includes a metal oxide including a titanium atom and a niobium atom.

The invention provides an all-day solar cell system that is capable of simultaneously generating and storing electricity, which allows efficient photocharge during the day and discharge at night.

A solid junction-type photoelectric conversion element (10) including a first conductive layer (2), an electric power generation layer (4), and a second conductive layer (6), which are laminated in this order, wherein the electric power generation layer (4) comprises: a perovskite compound represented by a composition formula ABX.sub.3, formed of an organic cation A, a metal cation B and a halide anion X, and a compound Z having no perovskite structure.

A photoelectric conversion element including: a first electrode; a photoelectric conversion layer; and a second electrode, wherein the photoelectric conversion layer includes an electron-transporting layer and a hole-transporting layer, the electron-transporting layer includes a lithium ion, the hole-transporting layer includes an organic hole-transporting material and a lithium salt, and lithium included in the electron-transporting layer is more than lithium included in the hole-transporting layer.