Refinement of solar absorbing black chrome microstructure and its relationship to optical degradation mechanisms

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.327475· OSTI ID:5111784

Zajac, G; Smith, G B; Ignatiev, A

An in depth characterization of the electrodeposited solar absorber black chrome resulting in refinement of the microstructural model of the coating is presented in light of current studies in valence band Auger electron spectroscopy, x-ray photoelectron spectroscopy, thermal desorption spectroscopy, secondary ion mass spectroscopy, and the chromium electrodeposition mechanism. Through the presented model, the structural and chemical parameters of the coating are linked to its optical response with the degradation of the optical response at elevated temperatures related to changes in these parameters. The degradation process is divided into two distinct phases. First, upon heating to low temperatures (< or approx. =300 /sup 0/C) the chromium hydroxide localized on the surface and within the microstructure of the film decomposes producing H/sub 2/O and chromium oxide leaving an expected microvoid-metallic particle structure. Heating to temperatures in excess of 300 /sup 0/C leads to the second degradation phase. The fine chromium crystallites comprising the film undergo oxidation and the metallic chromium component, responsible for the intrinsic optical absorption, is diminished. The optical model of the solar absorbing film has been refined within the effective medium approach to account for the flat response in the visible part of the spectrum.

• Research Organization: Department of Physics, University of Houston, Houston, Texas 77004
• OSTI ID: 5111784
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 51:10; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors &amp; Concentrators
AUGER ELECTRON SPECTROSCOPY
BLACK CHROME
BLACK COATINGS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COATINGS
CRYSTAL STRUCTURE
DECOMPOSITION
DEPOSITION
DESORPTION
ELECTRODEPOSITION
ELECTROLYSIS
ELECTRON SPECTROSCOPY
EMISSION
EQUIPMENT
FILMS
HIGH TEMPERATURE
IONS
LYSIS
MASS SPECTROSCOPY
MICROSTRUCTURE
PHOTOELECTRIC EFFECT
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
SECONDARY EMISSION
SOLAR ABSORBERS
SOLAR EQUIPMENT
SPECTROSCOPY
SURFACE COATING
VALENCE
VOIDS
X-RAY SPECTROSCOPY