Conversion of broadband energy to narrowband emission through double-sided metamaterialsf

fIn this paper, an energy harvesting/re-radiating device is proposed to realize high efficiency energy conversion in the solar thermophotovoltaic system. Such device consists of double-sided metamaterials which are assembled by a broadband absorber working in the major solar spectrum, and a back-by-back narrowband emitter working in the infrared band. It is theoretically proved that most of solar light (from 0.28 mu m to 4 mu m) can be collected, and then, converted to a sharp emission at the maximal response energy level (similar to 0.4 eV) of photovoltaic cells in thermal equilibrium state. The impact of high temperature (as large as 966 K) and the parasitic radiation on the performance is discussed and compensated by geometric optimization. (C) 2013 Optical Society of America