optical properties, thermal stability and characterization of cobalt Oxide films
There is currently a need in the solar energy industry to enhance the efficiency of collectors, especially concentrating collectors, which operate at temperatures above 300/sup 0/C. Absorber coatings have been found to increase the efficiency of collection by reducing thermal losses caused by reradiation of heat from the collector surface. In short, the collector is coated with a black film which has a high solar absorptance (..cap alpha..) but is transparent to IR wavelengths, to which the metal substrate is reflective. That is, it is a selective absorber. Black chrome, a composite film of chromium metal and chromium oxides, is currently used industrially for this purpose. However, it has been found to fail at prolonged times above 350/sup 0/C. Black cobalt has shown promise as an alternative for high temperature applications. This research project focused on the development of black cobalt as a selective solar absorber. The optical properties were considered as a function of various times at 400-500/sup 0/C. It was also of interest to determine the chemical composition of the films because changes in optical properties in the early hours of heating were found to be associated with the oxidation of the films.
- Research Organization:
- Solar Energy Res Inst., Golden, CO
- OSTI ID:
- 6990124
- Report Number(s):
- CONF-811013-
- Journal Information:
- Proc. - Electrochem. Soc.; (United States), Journal Name: Proc. - Electrochem. Soc.; (United States) Vol. 83-1; ISSN PESOD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
141000* -- Solar Collectors & Concentrators
ABSORPTIVITY
BLACK COATINGS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COATINGS
COBALT COMPOUNDS
COBALT OXIDES
CONCENTRATING COLLECTORS
EQUIPMENT
FILMS
OPTICAL PROPERTIES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RESEARCH PROGRAMS
SOLAR ABSORBERS
SOLAR COLLECTORS
SOLAR EQUIPMENT
SPECTRALLY SELECTIVE SURFACES
STABILITY
SURFACES
THERMAL DEGRADATION
THIN FILMS
TRANSITION ELEMENT COMPOUNDS