Investigation of thin film solar cells based on Cu/sub 2/S and certain ternary compounds. Final report, July 1, 1973--December 31, 1976

Technical Report · Thu Sep 01 04:00:00 EDT 1977

OSTI ID:6601937

Loferski, J J; Cometta, C

Copper sulfides, especially chalcocite (Cu/sub x/S with 2.000 < or = x < or = 1.995) and CuInS/sub 2/ have been studied as semiconductors for photovoltaic solar cell applications. Thin films (0.1 to 0.5..mu..) of copper sulfides have been produced by sulfurizing thinner films of evaporated copper and by chemical substitution of Cu ions for Cd ions in CdS single crystals and thin films. They have been characterized by x-ray diffraction, cathodoluminescence, optical transmission and reflectance, conductivity, Auger spectroscopy and scanning electron microscope analysis. Only chalocite and a tetragonal phase of composition Cu/sub x/S with x approximately 1.94 luminesce. Thin films of djurleite or diginite could not be produced by sulfurization. Solar cells involving heterojunctions between chalcocite and single crystals of n-CdS and n-Si have been fabricated and characterized. In the case of CdS substrate cells, the highest efficiencies (approximately 4%) were encountered when the Cu/sub x/S layer was produced by the Philips process; the next best, when the Cu/sub x/S layer was produced by the Clevite process (eta approximately 3%) and the poorest when the Cu/sub x/S layer was produced by sulfurizing a previously deposited thin film of Cu (eta approximately 2%) even though cathodoluminescence (CL) shows that the chalcocite produced by sulfurization is pure, whereas the chalcocites derived from CdS have a CL spectrum distinctly different from what is known to be pure chalcocite. The studies also show that the CL spectrum of the chalcocite derived from CdS changes with time whereas the sulfurized chalcocite is stable with time. A CL study of the effects of post fabrication treatments on chalcocite is also reported. Heterojunctions formed between p-chalcocite and n-Si have efficiencies up to about 4% and potential efficiencies up to 10%. The work on CuInS/sub 2/ was concentrated on preparation of single crystals and their characterization by x-ray analysis and CL.

• Research Organization: Brown Univ., Providence, RI (USA). Div. of Engineering
• OSTI ID: 6601937
• Report Number(s): TID-28692
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation &amp; Manufacture
AUGER ELECTRON SPECTROSCOPY
CADMIUM COMPOUNDS
CADMIUM SULFIDE SOLAR CELLS
CADMIUM SULFIDES
CATHODOLUMINESCENCE
CHALCOGENIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER SELENIDES
COPPER SULFIDES
DIFFRACTION
DIRECT ENERGY CONVERTERS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
FABRICATION
FILMS
INDIUM COMPOUNDS
INDIUM SELENIDES
INDIUM SULFIDES
INORGANIC PHOSPHORS
JUNCTIONS
LUMINESCENCE
MICROSCOPY
OPTICAL PROPERTIES
PERFORMANCE
PHOSPHORS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
RESEARCH PROGRAMS
SCATTERING
SELENIDES
SELENIUM COMPOUNDS
SEMICONDUCTOR JUNCTIONS
SEMIMETALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
SPECTROSCOPY
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION