Spectral selective surfaces for concentrated solar power receivers by laser sintering of tungsten micro and nano particles

Spectral selective surfaces for concentrated solar power receivers have been fabricated by laser sintering of tungsten micro and nano particles on stainless steel substrate under atmospheric pressure. Solar absorptance of ~83% has been experimentally measured for laser sintered tungsten layer and thermal emittance of ~11.6% at 300 K was computed based on the IR reflectance measurement. This high solar absorptance and low thermal emittance was achieved by a one micron thick laser sintered layer having sub-micron surface roughness with random spacing in the range from nanoscale to 5 μm. Laser sintering has not been applied for fabrication of solar receiver coatings and the first experimental demonstration is presented in this paper. Laser sintering under atmospheric pressure is a cost effective method for solar thermal applications.