Selenium photovoltaic device

Claim 1

A photovoltaic device comprising a transparent supportive substrate coated with an electrode comprising of a pellucid layer of conductive oxide having a surface whose work function is below about 4.5 electron volts, a continuous layer of crystalline P-type selenium less than about five microns but sufficient in thickness to be substantially free of shorting paths therethrough and forming a heterojunction with said oxide, a thin layer of tellurium interposed between said oxide and selenium layers providing a metallurgical bond therebetween; an electrode consisting of a metal having a work function in excess of about 5.0 electron volts contiguous the selenium layer providing an ohmic contact thereto, said selenium layer having a depletion region extending inwardly from said heterojunction in excess of about 1000 Angstroms and having a deficiency of oxygen relative to said selenium proximate said ohmic contact wherein the device when illuminated with solar energy or the equivalent thereof of an intensity of about 100 milliwatts per centimeter squared displays a conversion efficiency in excess of about 3.5%.

Claim 13

A method for producing a photovoltaic device having a body of polycrystalline selenium and displaying a sunlight engineering efficiency in excess of about 3.5%, said method comprising: coating a transparent substrate with a pellucid layer of conductive oxide having a surface whose work function is below about 4.5 electron volts; depositing on said coated substrate a thin layer of tellurium to provide a bond between the oxide and the selenium; forming on said tellurium a layer of amorphous selenium having a thickness less than about five microns but sufficient to be substantially free of shorting paths therethrough; heat treating said amorphous selenium layer at a temperature above about 200° C. and sufficient to crystallize said layer and form a heterojunction between said oxide and said crystallized selenium layer, said selenium having a depletion region extending inwardly from said heterojunction in excess of about 1000 Anstroms; depositing on said crystallized selenium layer an electrode of a metal whose work function exceeds about 5.0 electron volts to provide an ohmic contact to said selenium layer.

Claim 14

A method for producing a photovoltaic device having a body of polycrystalline selenium and displaying a sunlight engineering efficiency in excess of about 3.5%, said method comprising: coating a transparent substrate with a pellucid layer of conductive oxide having a surface whose work function is below about 4.5 electron volts; depositing on said coated substrate a thin layer of tellurium to provide a bond between the oxide and the selenium; forming on said tellurium a layer of amorphous selenium having a thickness less than about five microns but sufficient to be substantially free of shorting paths therethrough; heat treating said amorphous selenium layer at a temperature above about 200° C. and sufficient to crystallize said layer and form a heterojunction between said oxide and said crystallized selenium layer, said selenium having a depletion region extending inwardly from said heterojunction in excess of about 1000 Anstroms; depositing on said crystallized selenium layer an electrode of a metal whose work function exceeds about 5.0 electron volts to provide an ohmic contact to said selenium layer.