Thin film photovoltaic diodes and method for making same

Patent · Tue Nov 08 04:00:00 EST 1977

OSTI ID:7152368

Kirkorian, E; Crisp, M J

Photovoltaic diodes prepared by the methods of the invention include p-n (or n-p) heterojunction or homojunction diodes as well as Schottky barrier diodes where both elements of the diode comprise thin monocrystalline films of Pb/sub 1-x/Sn/sub x/Te or a thin monocrystalline film of Pb/sub 1-x/Sn/sub x/Te and an appropriate thin barrier metal film. Such a monocrystalline Pb/sub 1-x/Sn/sub x/Te film is sputter deposited, has a composition Pb/sub 1-x/Sn/sub x/Te which may range from x = 0.0 to about x = 0.3 and, consequently, can be preselected to have a photovoltaic response with response cutoff wavelengths ranging from about 6.0 ..mu..m to about 25 ..mu..m at 77/sup 0/K. The first film is sputter deposited under controlled conditions in accordance with the present method, including at low pressure of selected gas and at selected substrate temperature and film growth rate conditions with or without substrate temperature and film growth rate condition with or without substrate bias voltage of from about +30 volts to about -30 volts, so as to control the composition and stoichiometry of the resulting film as well as its carrier type, carrier concentration and Hall mobility to provide selected electro-optical properties. Thereupon a second film is deposited, which is either a film of composition Pb/sub 1-x/sub 1//Sn/sub x/sub 1//Te where x/sub 1/ may range from 0.0 to about 0.3, in which case this film is deposited directly upon the first film, or a film of thin barrier metal which may be deposited on the first film. The thin barrier metal film is utilized in preparing Schottky type diodes and the film may be lead, indium or the like. The present method provides in a very economical manner at moderate conditions high sensitivity photovoltaic diodes utilizing PbSnTe films requiring no costly and time consuming post-deposition treatment such as annealing.

• Assignee: General Dynamics Corp.
• Patent Number(s): US 4057476
• OSTI ID: 7152368
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CHALCOGENIDES
CRYSTAL GROWTH
CRYSTALS
DIRECT ENERGY CONVERTERS
FABRICATION
FILMS
JUNCTIONS
LEAD COMPOUNDS
LEAD TELLURIDES
MONOCRYSTALS
P-N JUNCTIONS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SCHOTTKY BARRIER DIODES
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMICONDUCTOR JUNCTIONS
SOLAR CELLS
SPUTTERING
TELLURIDES
TELLURIUM COMPOUNDS
TIN COMPOUNDS
TIN TELLURIDES