Spectral properties of two-dimensional (2D) metal surface gratings are investigated to develop high performance
solar selective absorbers and sky radiators. Numerical calculations based on rigorous coupled-wave analysis (RCWA)
are performed and surface gratings are fabricated on silicon substrates by means of photolithography and etching
process. Reflectivity spectra of the samples are measured and they show good spectral selectivity for each application. In order to fabricate surface microstructures in large area with low cost, direct metal imprinting technology are
proposed. A microstructured nickel metal mold for the solar selective absorber surface is fabricated by means of
electroplating technique and imprint experiments are performed on copper metal surface using mechanical pressing
system. As a result, some parts of the surface structures are successfully transferred onto copper substrate.