The present disclosure relates to a composition that includes a perovskite phase having the stoichiometry ABX.sub.3 and a perovskite-like phase having the stoichiometry A′.sub.2A″B′.sub.2X′, where A is a first cation, B is a second cation, X is a first anion, A′ is a third cation, A″ is a fourth cation, B′ is a fifth cation, X′ is a second anion, and A′ is different than A″.

The present disclosure relates to a composition that includes a perovskite phase having the stoichiometry ABX.sub.3 and a perovskite-like phase having the stoichiometry A′.sub.2A″B′.sub.2X′, where A is a first cation, B is a second cation, X is a first anion, A′ is a third cation, A″ is a fourth cation, B′ is a fifth cation, X′ is a second anion, and A′ is different than A″.

A photoelectric conversion device in an embodiment includes a first photoelectric conversion part including a first transparent electrode, a first photoelectric conversion layer, and a first counter electrode and a second photoelectric conversion part including a second transparent electrode, a second photoelectric conversion layer, and a second counter electrode, the first photoelectric conversion part and the second photoelectric conversion part being provided on a transparent substrate. The first counter electrode and the second transparent electrode are electrically connected by a connection part. As for the first photoelectric conversion layer and the second photoelectric conversion layer, adjacent portions of the adjacent first and second photoelectric conversion layers are electrically separated by an inactive region having electrical resistance higher than that of the first and second photoelectric conversion layers.

Organic photovoltaic cells (OPVs) and their compositions are described herein. In one or more embodiments, the acceptor with an active layer of an OPV includes is a non-fullerene acceptor. Such non-fullerene acceptors may provide improved OPV performance characteristics such as improved power conversion efficiency, open circuit voltage, fill factor, short circuit current, and/or external quantum efficiency. One example of a non-fullerene acceptor is (4,4,10,10-tetrakis(4-hexylphenyl)-5,11-(2-ethylhexyloxy)-4,10-dihydro-dithienyl[1,2-b:4,5b′]benzodi-thiophene-2,8-diyl) bis(2-(3-oxo-2,3-dihydroinden-5,6-dichloro-1-ylidene) malononitrile.

In one aspect, window inserts are described herein, which can modulate transmission of electromagnetic radiation through a window and can be self-powered. In some embodiments, a window insert comprises a photovoltaic device, the photovoltaic device including a photosensitive layer having peak absorption between 250 nm and 450 nm and an average transmittance of at least 50 percent in the visible region of the electromagnetic spectrum.

In one aspect, window inserts are described herein, which can modulate transmission of electromagnetic radiation through a window and can be self-powered. In some embodiments, a window insert comprises a photovoltaic device, the photovoltaic device including a photosensitive layer having peak absorption between 250 nm and 450 nm and an average transmittance of at least 50 percent in the visible region of the electromagnetic spectrum.

A photoelectric converter includes: a first electrode; a second electrode; a first photoelectric conversion layer; a second photoelectric conversion layer; a first buffer layer; and a second buffer layer. The second electrode is disposed to be opposed to the first electrode. The first photoelectric conversion layer is provided between the first electrode and the second electrode. The first photoelectric conversion layer includes a first dye material and a first carrier transport material. The second photoelectric conversion layer is stacked on the second electrode side of the first photoelectric conversion layer between the first electrode and the second electrode. The second photoelectric conversion layer includes a second dye material and a second carrier transport material. The second dye material has a light absorption waveform different from a light absorption waveform of the first dye material. The first buffer layer has a first electrical conduction type. The first buffer layer is provided between the first electrode and the first photoelectric conversion layer. The second buffer layer has a second electrical conduction type different from the first electrical conduction type. The second buffer layer is provided between the second electrode and the second photoelectric conversion layer.

A tandem cell is provided in the present disclosure, which relates to the technical field of photovoltaics, so as to form a functional layer with high film ordering on a bottom cell, thereby improving photoelectric conversion efficiency of the tandem cell. The tandem cell includes: a bottom cell with a textured surface; a hole transport layer formed on the textured surface of the bottom cell; a second ordered induction layer and a perovskite absorption layer formed on the hole transport layer, the second ordered induction layer being located between the hole transport layer and the perovskite absorption layer; and a transparent conductive layer formed on the perovskite absorption layer. An inducing material contained in the second ordered induction layer is organic ammonium salt or inorganic lead compound. The tandem cell according to the present disclosure is a tandem cell with a perovskite solar cell as a top cell.

A tandem cell is provided in the present disclosure, which relates to the technical field of photovoltaics, so as to form a functional layer with high film ordering on a bottom cell, thereby improving photoelectric conversion efficiency of the tandem cell. The tandem cell includes: a bottom cell with a textured surface; a hole transport layer formed on the textured surface of the bottom cell; a second ordered induction layer and a perovskite absorption layer formed on the hole transport layer, the second ordered induction layer being located between the hole transport layer and the perovskite absorption layer; and a transparent conductive layer formed on the perovskite absorption layer. An inducing material contained in the second ordered induction layer is organic ammonium salt or inorganic lead compound. The tandem cell according to the present disclosure is a tandem cell with a perovskite solar cell as a top cell.

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.