Emerging materials for solar cell applications: electrodeposited CdTe. Final report, February 14, 1979-February 14, 1980
Thin film gold/polycrystalline cadmium telluride Schottky solar cells made by electrodepositing the semiconductor on an ITO-coated glass substrate serving also as an ohmic contact demonstrated an internal efficiency of 4% over 2 mm/sup 2/ areas. During the year being reported upon, Monosolar devoted mator attention to refining the electroplating process and determining the parameters governing CdTe film stoichiometry, grain size, substrate adhesion, and quality. UCLA acting as a Monosolar sub-contractor characterized both the CdTe films themselves and solar cells made from them. Techniques were developed for making measurements on films often less than 1 micron in thickness. The highest values achieved for efficiency parameters, not necessarily all in the same cell, were V/sub oc/ = 0.5 V, J/sub sc/ = 11 mA/cm/sup 2/, and fill factor = 0.55 before corrections in the absence of anti-reflection coatings. Typical resistivities for n-CdTe films were 10/sup 5/ ..cap omega..-cm. Lifetimes of about 10/sup -10/ sec were measured. Absorption coefficient of these films is in the order of 10/sup 4/ for lambda < 0.7 ..mu..m. Measured energy gap for these CdTe films is 1.55 eV, sightly higher than the 1.45 eV value for single crystal CdTe. The activation energy of the dominating trap level is 0.55 eV. Trap density is in the order of 10/sup 16//cm/sup 3/. Schottky diodes were of excellent quality and pinhole-free. The measured barrier height varied between 0.75 and 0.85 eV. Rectification ratios of 10/sup 4/ were obtained reproducibly. Films measure about 1 inch square. Indications are that larger and more efficient low cost solar devices can readily be obtained soon using the techniques developed in this program.
- Research Organization:
- Monosolar, Inc., Santa Monica, CA (USA)
- DOE Contract Number:
- AC04-79ET23008
- OSTI ID:
- 5116523
- Report Number(s):
- DOE/ET/23008-T1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Improved semiconductors for photovoltaic solar cells. Final report, July 15, 1977-July 14, 1978
Emerging materials for solar cell applications: electrodeposited CdTe. First quarter report, February 15-May 15, 1980
Related Subjects
36 MATERIALS SCIENCE
CADMIUM TELLURIDE SOLAR CELLS
FABRICATION
CADMIUM TELLURIDES
ELECTRICAL PROPERTIES
ELECTROPLATING
ADHESION
CARRIER LIFETIME
DATA
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRODEPOSITED COATINGS
ENERGY GAP
FILL FACTORS
FILMS
GRAIN SIZE
GRAPHS
INDIUM OXIDES
POLYCRYSTALS
SCHOTTKY BARRIER DIODES
SUBSTRATES
TIN OXIDES
TRAPS
CADMIUM COMPOUNDS
CHALCOGENIDES
COATINGS
CRYSTAL STRUCTURE
CRYSTALS
DATA FORMS
DEPOSITION
DIRECT ENERGY CONVERTERS
ELECTRODEPOSITION
ELECTROLYSIS
EQUIPMENT
INDIUM COMPOUNDS
INFORMATION
LIFETIME
LYSIS
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PLATING
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SIZE
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
TELLURIDES
TELLURIUM COMPOUNDS
TIN COMPOUNDS
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture