Abstract: There is provided a multi-junction photovoltaic device comprising a first sub-cell disposed over a second sub-cell, the first sub-cell comprising a photoactive region comprising a layer of perovskite material and the second sub-cell comprising a silicon heterojunction (SHJ).

Abstract: A photovoltaic device comprises a PIN structure in which a p-type hole transporting layer (2) is carried by a substrate (1) and a perovskite layer (3) and an n-type electron transporting layer (4) are arranged in sequence on the p-type layer. A light transmissive electrically conductive layer (9) is provided on top of the n-type electron transporting layer to form a light receiving top surface. Between the n-type electron transporting layer and the light transmissive conductive layer there is provided a structure comprising two inorganic electrically insulative layers (6, 8) having a layer of a conductive material (7) therebetween, wherein the two inorganic electrically insulative layers comprise a material having a band gap of greater than 4.5 eV and the layer of a conductive material comprises a material having a band gap of less than the band gap of the electrically insulative layers, wherein each electrically insulative layer forms a type-1 offset junction with the layer of conductive material.

Abstract: A formulation for use in the preferential formation of thin films of a perovskite material AMX3 with a certain required crystalline structure, wherein said formulation comprises two or more compounds which between them comprise one or more first organic cations A; one or more metal cations M; one or more second cations A?; one or more first anions X and one or more second anions X?.

Abstract: A formulation for use in the preferential formation of thin films of a perovskite material AMX 3 with a certain required crystalline structure, wherein said formulation comprises two or more compounds which between them comprise one or more first organic cations A; one or more metalcations M; one or more second cations A?; one or more first anions X and one or more second anions X?.

Abstract: A formulation for use in the preferential formation of thin films of a perovskite material AMX3 with a certain required crystalline structure, wherein said formulation comprises two or more compounds which between them comprise one or more first organic cations A; one or more metal cations M; one or more second cations A?; one or more first anions X and one or more second anions X?.

Abstract: There is provided a multi-junction photovoltaic device (100) comprising a first sub-cell (110) disposed over a second sub-cell (120), the first sub-cell comprising a photoactive region comprising a layer of perovskite material and the second sub-cell comprising a silicon heterojunction (SHJ).

Abstract: There is provided a photovoltaic device that comprises a front electrode, a back electrode, and disposed between the front electrode and the back electrode, an electron transporter region comprising an electron transporter layer; a hole transporter region comprising a hole transporter layer, and a layer of perovskite semiconductor disposed between and in contact with the electron transporter layer and the hole transporter layer. The electron transporter region is nearest to the front electrode and the hole transporter region is nearest to the back electrode, and the electron transporter layer comprises any of a chalcogenide material and an organic material and has a thickness of at least 2 nm.

Abstract: A formulation for use in the preferential formation of thin films of a perovskite material AMX 3 with a certain required crystalline structure, wherein said formulation comprises two or more compounds which between them comprise one or more first organic cations A; one or more metalcations M; one or more second cations A?; one or more first anions X and one or more second anions X?.