Article

CVD black chrome coatings for high temperature photothermal energy conversion

Ruhrchemie Aktiengesellschaft, PO Box 130160, D-4200 Oberhausen-Holten, Fed. Rep. Germany
Solar Energy Materials 07/1985; 12(3):239-248. DOI: 10.1016/0165-1633(85)90062-0

ABSTRACT Black chrome absorber coatings have been developed by CVD-technique involving deposition of chrome hexacarbonyl. The deposition of the black chrome absorber films by CVD proceeds through pyrolysis of chrome hexacarbonyl at atmospheric pressure in the presence of oxygen. The black chrome absorber coatings demonstrate a significant solar absorptance (as deposited α > 0.95) coupled with a high infrared reflectance (as deposited ϵ < 0.1) which is necessary for efficient conversion of solar energy into heat. Coatings deposited on steel substrates have remained intact and substantially after 1000 h of lifetime testing in air at 600°C. The characterization of these selective absorber coatings has been carried out by measuring the thermal optical properties (α, ϵ), by X-ray examination and by surface analysis using SEM and AES. The deposition at atmospheric pressure offering the potential of large-scale continuous flow-through manufacture. Substrates of such long pipes can be easily coated for solar farm plants.

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