摘要 |
There has been provided composite coatings for solar absorber surfaces wherein solar radiation impinges on one surface of the absorber and which absorber is adapted to transfer energy so received from the impinging solar radiation in the form of sensible heat to a working fluid in contact with a delivery surface therewith comprising: a smooth surface absorber substrate having a first coating of metal oxides deposited on the smooth layer which oxides are selected from the group, consisting essentially of tin, antimony, indium and iron, and a second coating of metal oxides deposited on the first coating selected from the aforementioned group for said first layer; said first and second coatings disposed so as to exhibit a relatively high absorption characteristic alpha of at least 0.85 in the solar wavelength range, and a relatively low emissivity characteristic epsilon of less than 0.2 within the wavelength range of the infrared greater than about 2 micrometers.
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