Metamaterial-based frustum of cones array nanostructure for efficient absorber in the solar spectral band

Solar spectrum absorbing and harvesting are important for the utilization of solar energy. In this paper, we propose a metamaterial-based frustum of cones array solar energy absorber which appears an average absorptivity of 0.98 in the entire spectrum (i. e., 0.2-2.5 mu m) with independent of the incoming light polarization state as well as the wide incident angle of as large as 50 degrees. The efficient light harvesting property can be explained as the synergistic effect of the slow light mode, localized surface plasmon resonant effect and absorption induced by inter-band transition.