Research on selective solar absorber with submicron-period surface microstructures

摘要

Optical properties of submicron-period surface microstructures on refractory metal have been investigated for developing new selective solar absorbers. Calculations based on rigorous coupled-wave analysis (RCWA) estimate that the two dimensional series of sub micron microcavities on W surfaces show a high solar absorptance and a low thermal emittance. It is expected that they have a higher efficiency as a selective solar absorber than conventional selective coatings under high temperatures. Microstructured W surfaces with a structural period of 450nm are fabricated by means of fast atom beam etching with a highly ordered porous alumina membrane mask. The sample shows a good spectral selectivity, and it is clarified that microstructured W surfaces can be applied for a selective solar absorber.