👉 Electroluminescence is a phenomenon that occurs when certain materials, such as metals or semiconductors, emit light when exposed to an electric field. This light can be emitted in various colors and wavelengths, depending on the material's chemical composition and surface properties. In electrochemical cells, for example, some materials (such as gold) are used as cathodes, while others (such as silver) are used as anode or positive electrode. When these materials are exposed to an electric