A photochemical electrode includes: an electrically conductive layer; and a photoexcitation material layer provided over the electrically conductive layer and including a photoexcitation material, wherein the photoexcitation material layer is one of a first photoexcitation material layer in which a potential of the conduction band minimum decreases from a second surface opposite to a first surface on the side of the electrically conductive layer toward the first surface and a second photoexcitation material layer in which a potential of the valence band maximum decreases from the second surface toward the first surface.

A photochemical electrode includes: an electrically-conductive layer; and a photo-excited material layer including a photo-excited material provided over the electrically-conductive layer, wherein in a surface of the photo-excited material layer, a lattice plane having highest atomic density in a crystal structure of the photo-excited material is oriented in a surface direction of the surface of the photo-excited material layer.

Various perovskite solar cell embodiments include a flexible metal substrate (e.g., including a metal doped TiO2 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.

Photovoltaic devices such as solar cells, hybrid solar cell-batteries, and other such devices may include an active layer disposed between two electrodes. The active layer may have perovskite material and other material such as mesoporous material, interfacial layers, thin-coat interfacial layers, and combinations thereof. The perovskite material may be photoactive. The perovskite material may be disposed between two or more other materials in the photovoltaic device. Inclusion of these materials in various arrangements within an active layer of a photovoltaic device may improve device performance. Other materials may be included to further improve device performance, such as, for example: additional perovskites, and additional interfacial layers.

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.

A photovoltaic device comprises plural layers separated into plural cells, each comprising a region of a photoactive layer and electrodes on opposite sides thereof. Each of the regions of the photoactive layer are formed comprising a first part that comprises photoactive material and a second part that is not photoactive and that has a greater transmittance of visible light than the light absorbing photoactive material, in pre-selected locations, or in a pre-selected distribution of locations, across the region of the photoactive layer. One of the first and second parts are located in plural separate areas within the other of the first and second parts. The transparency of the photovoltaic device is increased by the transmission of light through the second part that is not photoactive.

A photoelectric conversion element may include a first substrate, a first transparent electrode disposed on the first substrate, a hole-blocking layer disposed on the first transparent electrode, an electron-transporting layer that is disposed on the hole-blocking layer and includes an electron-transporting semiconductor on a surface of which a photosensitizing compound is adsorbed, a hole-transporting layer that is connected to the electron-transporting layer and includes a hole-transporting material, and a second electrode disposed on the hole-transporting layer, wherein the photoelectric conversion element includes an output extraction terminal part configured to extract electricity out from the photoelectric conversion element, and the output extraction terminal part is formed with a plurality of micropores piercing through the hole-blocking layer.

Described herein is a liquid electrophotographic photovoltaic ink composition comprising: a dispersion of a material with a perovskite structure, a thermoplastic resin and conductive particles in a carrier liquid; wherein the material with a perovskite structure has a chemical formula selected from ABX.sub.3 and A.sub.2BX.sub.6; wherein A is a cation, B is a cation and X is an anion; and wherein the thermoplastic resin comprises: a copolymer of an alkylene monomer and a monomer having acidic side groups; and/or a copolymer of an alkylene monomer and an ethylenically unsaturated monomer comprising an epoxide; and/or a copolymer of an alkylene monomer, an ethylenically unsaturated monomer comprising an epoxide, and a monomer selected from a monomer having acidic side groups, a monomer having ester side groups and a mixture thereof. Also described is a method of producing a photovoltaic cell using the LEP ink and the printed cell produced by the method.

The present invention relates to a polymer, an organic solar cell comprising the polymer, and a perovskite solar cell comprising the polymer. The polymer according to the present invention has excellent absorption ability for visible light and an energy level suitable for the use as an electron donor compound in a photo-active layer of the organic solar cell, thereby increasing the light conversion efficiency of the organic solar cell. In addition, the polymer according to the present invention has high hole mobility, and is used as a compound for a hole transport layer, and thus can improve efficiency and service life of the perovskite solar cell without an additive.

The present disclosure relates to novel perovskite solar cells, and the method of making and using the novel perovskite solar cells. More specifically, a triple cation perovskite solar cell device containing a multifunctional capping layer (MCL) of R.sup.1NH.sub.3.sup.+ and/or a thin layer of two-dimensional (2D) material of (R.sup.1NH.sub.3.sup.+).sub.2(A.sup.+).sub.n−1(M.sup.2+).sub.n(X.sup.−).sub.3n+1 on top of the commonly used ABX3 perovskite, with enhanced power conversion efficiency of 22.06% (from 19.94%) with long-term stability over 1000 hours under continuous illumination has been developed.