Development of copper sulfide/cadmium sulfide thin-film solar cells
The purpose of this work has been to identify aspects of cell fabrication and treatment which are critical for achieving high efficiency Cu/sub 2/S/CdS solar cells. In approaching the problem several comparisons were made of the effects of specific steps in two methods of cell fabrication. These methods had previously given cells of about 6% and a maximum of 9% efficiency. Three areas requiring special attention and specific means to achieve acceptable results were identified. (1) The Cu/sub 2/S/CdS heterojunction area must be minimized. If single source evaporations of CdS are made on substrates whose temperatures (approx. 220/sup 0/C) are monitored and controlled using welded thermocouples, the CdS films will have adequately large grains (grain diameter greater than or equal to 2 ..mu..m) and will not develop significant etch pits during texturing in a mild etchant solution. (2) The termination of the wet barrier processing steps must be done carefully. An acceptable termination involves minimizing the amount of cuprous chloride retained on the cell surface during transfer to a rinsing stage while providing adequate exclusion of air from the space above the surface of the cuprous chloride solution. (3) Once formed, the Cu/sub 2/S layer should not be exposed to high temperatures (>100/sup 0/C) for long periods of time (> 5 min) if surface adsorbed moisture or oxygen are present. Heat treatments in ampoules under flowing hydrogen atmospheres should be preceded and followed by periods of at least 30 minutes at room temperature in the reducing ambient. If all these precautions are taken, wet chemical barrier processing of thermally evaporated CdS films on zinc-plated copper foil substrates yields cells of nearly 8% conversion efficiency without AR coating.
- Research Organization:
- Westinghouse Research and Development Center, Pittsburgh, PA (USA)
- DOE Contract Number:
- AC02-77CH00178
- OSTI ID:
- 6565194
- Report Number(s):
- SERI/PR-8143-1-T3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of copper sulfide/cadmium sulfide thin-film solar cells. Fifth technical progress report, 13 July 1980-12 October 1980
Cadmium sulfide/copper sulfide heterojunction cell research. Technical progress report No. 4, July 1-September 30, 1978
Related Subjects
36 MATERIALS SCIENCE
CADMIUM SULFIDE SOLAR CELLS
FABRICATION
CADMIUM SULFIDES
VACUUM COATING
COPPER SULFIDES
EVAPORATION
FILMS
GRAIN SIZE
HEAT TREATMENTS
MICROSTRUCTURE
SUBSTRATES
CADMIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTAL STRUCTURE
DEPOSITION
DIRECT ENERGY CONVERTERS
EQUIPMENT
INORGANIC PHOSPHORS
PHASE TRANSFORMATIONS
PHOSPHORS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SIZE
SOLAR CELLS
SOLAR EQUIPMENT
SULFIDES
SULFUR COMPOUNDS
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture