Method of making improved photovoltaic heterojunction structures

Abstract

Abstract A three layer, photovoltaic structure having polycrystalline semiconductor layers disposed in series optically and in sequential touching contact includes a relatively wide optical bandgap energy window layer, a light-absorbing layer and a third, relatively wide bandgap energy layer that forms a minority carrier mirror with the light-absorbing layer. All three layers have different compositions so that the structure includes two heterojunctions. The light-absorbing layer and third layer are of the same conductivity type. The structure is conveniently realized using II-VI semiconductor compounds such as a cadmium sulfide or zinc sulfide window layer, a mercury cadmium telluride, cadmium telluride, zinc cadmium telluride or mercury zinc telluride light-absorbing layer and a third layer of cadmium telluride, zinc telluride, zinc cadmium telluride, mercury cadmium telluride or cadmium manganese telluride. Cadmium is present in at least two of the three layers of the novel structures. Tellurium is present in two of the three layers. Structures according to the invention may be conveniently formed by electrodeposition and may employ opaque or transparent substrates depending on the particular semiconductor materials used and their relative positions.

Inventors

• 👤 Miroslav Ondris
• 👤 Marty A. Pichler

Bibliographic Details