Abstract

Solar cell based semiconductors (Si, GaAs, CIS, CIGS and so on) are widely used. The light wavelength which can be used for energy conversion depends on their bandgap width; the limitation of single crystalline silicon is approximately 1100 nm [1]. The longer-wavelength, semiconductor cannot harvest light efficiently and be used for conversion. In addition, the shorter-wavelength light (i.e. UV light) becomes loss as thermal energy and rising up the cell temperature causes reducing the conversion efficiency. We focused on the heat generated by light absorber using for the energy conversion. Black semiconductor (i.e. black silicon; b-Si, black germanium; b-Ge) which has nanoneedle structures on the surface of substrate can be used low reflection and high absorption of light. In this study, we constructed the photo-thermal voltaic conversion system via black semiconductors and thermo-electro devices and evaluated its efficiency of light absorption

© 2014 Japan Society of Applied Physics, Optical Society of America