Abstract: A high efficiency selenium photovoltaic solar cell comprises a transparent base; a pellucid layer of conductive oxide; a layer of polycrystalline selenium forming a heterojunction to the underlying oxide; a thin layer of tellurium interposed between the oxide and selenium layers providing a metallurgical bond therebetween; a layer of high work function metal forming an ohmic contact to the selenium layer. A process of optimizing the optical and electrical characteristic of each component of the solar cell results in increased sunlight engineering efficiencies in excess of about 3.5%.