Abstract: A problem of the invention is to prevent a substrate from being damaged with a metal stylus upon mechanical patterning.

Abstract: A problem of the invention is to prevent a substrate from being damaged with a metal stylus upon mechanical patterning.

Abstract: 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.

Abstract: 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.

Abstract: 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.