Showa Shell Sekiyu K.k.

Showa Shell Sekiyu Kabushiki Kaisha

Muneyori Tachiyuki

Katsumi Kushiya

Takahisa Kase

A thin-film light absorbing layer which is regulated so as to have any desired gallium concentration and which is capable of attaining a high open-circuit voltage is formed by a simple method at a temperature lower than the softening point of the soda-lime float glass. A light absorbing layer is formed by forming a back electrode on a soda-lime float glass substrate, forming on the back electrode layer a stacked precursor film including a copper-gallium alloy layer and an indium layer by sputtering, and then heating the precursor film in an atmosphere of selenium and/or sulfur.

Equipment for producing thin-film solar cell

Method for producing thin-film solar cell and equipment for producing

A solar cell with a heightened open-circuit voltage and improved junction quality of the interface between an interfacial layer (or buffer layer) and a thin-film light absorbing layer is disclosed. A thin-film solar cell is fabricated on a glass substrate and includes a metallic back electrode, a light absorbing layer, an interfacial layer, a window layer, and an upper electrode. The solar cell is characterized by the light absorbing layer. The light absorbing layer is a thin film of p-type Cu(InGa)Se.sub.2 (CIGS) of the Cu-III-VI.sub.2 chalcopyrite structure and has such a gallium concentration gradient that the gallium concentration gradually (gradationally) increases from the surface thereof to the inside, thereby attaining a heightened open-circuit voltage. The light absorbing layer has on its surface an ultrathin-film surface layer of Cu(InGa)(SeS).sub.2 (CIGSS), which has such a sulfur concentration gradient that the sulfur concentration abruptly decreases from the surface thereof (i.e., from the interfacial layer side) to the inside, thereby improving interfacial junction characteristics.

Growing community of inventors

Tokyo, Japan

Muneyori Tachiyuki