TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compound: The n-layer comprises copper sulfide compound, copper selenide compound, copper telluride compound, indium-tin oxide compound, zinc oxide compound and/or tin oxide compound. The i-layer comprises copper sulfide compound, divalent metal copper sulfide compound, divalent metal copper sulfide fluoride compound, divalent metal copper sulfide oxide compound, trivalent metal copper sulfide compound, trivalent metal copper sulfide fluoride compound, trivalent metal copper oxide sulfide compound, quadrivalent metal copper sulfide compound, quadrivalent metal copper sulfide fluoride compound and/or quadrivalent metal copper sulfide oxide compound. The p-layer comprises divalent metal copper sulfide compound, divalent metal copper sulfide fluoride compound, divalent metal copper sulfide oxide compound, trivalent metal copper sulfide compound, trivalent metal copper sulfide fluoride compound, trivalent metal copper oxide sulfide compound, quadrivalent metal copper sulfide compound, quadrivalent metal copper sulfide fluoride compound and/or quadrivalent metal copper sulfide oxide compound. When n-layer comprises copper selenide compound, the i-layer comprises copper-indium-gallium diselenide compound, copper divalent metal selenide compound, copper divalent metal selenide fluoride compound, copper divalent metal selenide oxide compound, copper trivalent metal selenide compound, copper trivalent metal selenide fluoride compound, copper trivalent metal selenide oxide compound, copper quadrivalent metal selenide compound, copper quadrivalent metal selenide fluoride compound and/or copper quadrivalent metal selenide oxide compound, and the p-layer comprises compound same as that in i-layer except copper-indium-gallium diselenide compound. When n-layer comprises copper telluride compound, the i-layer comprises copper telluride compound, copper divalent metal telluride compound, copper divalent metal telluride fluoride compound, copper divalent metal telluride oxide compound, copper trivalent metal telluride compound, copper trivalent metal telluride fluoride compound, copper trivalent metal telluride oxide compound, copper quadrivalent metal telluride compound, copper quadrivalent metal telluride fluoride compound and/or copper quadrivalent metal telluride oxide compound, and the p-layer comprises compound same as that in i-layer except copper telluride compound. When n-layer comprises indium-tin oxide, zinc oxide or tin oxide, the i-layer comprises copper oxide compound, copper divalent metal oxide compound, copper divalent metal oxide fluoride compound, copper trivalent metal oxide compound, copper trivalent metal oxyfluoride compound, copper quadrivalent oxide compound and/or copper quadrivalent oxide fluoride compound, and the p-layer comprises compound same as that in i-layer except copper oxide compound. Each of n-, i- and p-layers common anion selected from oxygen, sulfur, selenium and tellurium, preferably oxygen and sulfur.