A solar cell of an embodiment includes: a substrate; an n-electrode; an n-type layer; a p-type light absorption layer which is a semiconductor of a Cu-based oxide; and a p-electrode. The n-electrode is disposed between the substrate and the n-type layer. The n-type layer is disposed between the n-electrode and the p-type light absorption layer. The p-type light absorption layer is disposed between the n-type layer and the p-electrode. The n-type layer is disposed closer to a light incident side than the p-type light absorption layer. The substrate is a single substrate included in the solar cell.

A solar cell according to an embodiment includes a p-electrode, a p-type light-absorbing layer containing a cuprous oxide or/and a complex oxide of cuprous oxides as a main component on the p-electrode, an n-type layer containing an oxide containing Ga on the p-type light-absorbing layer, and an n-electrode. A first region is included between the p-type light-absorbing layer and the n-type layer. The first region is a region from a depth of 2 nm from an interface between the p-type light-absorbing layer and the n-type layer toward the p-type light absorbing layer to a depth of 2 nm from the interface between the p-type light-absorbing layer and the n-type layer toward the n-type layer. Cu, Ga, M1, and O are contained in the first region. M1 is one or more elements selected from the group consisting of Sn, Sb, Ag, Li, Na, K, Cs, Rb, Al, In, Zn, Mg, Si, Ge, N, B, Ti, Hf, Zr, and Ca. A ratio of Cu, Ga, M1, and O is a1:b1:c1:d1. a1, b1, c1, and d1 satisfy 1.80≤a1≤2.20, 0.005≤b1≤0.05, 0≤c1≤0.20, and 0.60≤d1≤1.00.

A method for growing a transition metal dichalcogenide layer involves arranging a substrate having a first transition metal contained pad is arranged in a chemical vapor deposition chamber. A chalcogen contained precursor is arranged upstream of the substrate in the chemical vapor deposition chamber. The chemical vapor deposition chamber is heated for a period of time during which a transition metal dichalcogenides layer, containing transition metal from the first transition metal contained pad and chalcogen from the chalcogen contained precursor, is formed in an area adjacent to the first transition metal contained pad.

A method for growing a transition metal dichalcogenide layer involves arranging a substrate having a first transition metal contained pad is arranged in a chemical vapor deposition chamber. A chalcogen contained precursor is arranged upstream of the substrate in the chemical vapor deposition chamber. The chemical vapor deposition chamber is heated for a period of time during which a transition metal dichalcogenides layer, containing transition metal from the first transition metal contained pad and chalcogen from the chalcogen contained precursor, is formed in an area adjacent to the first transition metal contained pad.

A method for manufacturing a stacked thin film of an embodiment includes forming a p-electrode on a substrate, forming a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode, and performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides. An ozone partial pressure in the oxidation treatment is 5 [Pa] or more and 200 [Pa] or less, a treatment temperature in the oxidation treatment is 273 [K] or more and 323 [K] or less, and a treatment time in the oxidation treatment is 1 second or more and 60 minutes or less.

A method for manufacturing a stacked thin film of an embodiment includes forming a p-electrode on a substrate, forming a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode, and performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides. An ozone partial pressure in the oxidation treatment is 5 [Pa] or more and 200 [Pa] or less, a treatment temperature in the oxidation treatment is 273 [K] or more and 323 [K] or less, and a treatment time in the oxidation treatment is 1 second or more and 60 minutes or less.

A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

A semiconductor material having the molecular formula Cu2l2Se6 is provided. Also provided are solid solutions of semiconductor materials having the formulas Cu2lxBr2-xSeyTe6-y and Cu2lxBr2-xSeyS6-y, where 0≤x≤1 and 0≤y≤3. Methods and devices that use the semiconductor materials to convert incident radiation into an electric signal are also provided. The devices include optoelectronic and photonic devices, such as photodetectors, photodiodes, and photovoltaic cells.

A semiconductor material having the molecular formula Cu2l2Se6 is provided. Also provided are solid solutions of semiconductor materials having the formulas Cu2lxBr2-xSeyTe6-y and Cu2lxBr2-xSeyS6-y, where 0≤x≤1 and 0≤y≤3. Methods and devices that use the semiconductor materials to convert incident radiation into an electric signal are also provided. The devices include optoelectronic and photonic devices, such as photodetectors, photodiodes, and photovoltaic cells.