Silicon materials. Electrical and optical properties

This chapter presents the material properties of silicon which are relevant for an understanding and modelling of the performance of typical silicon solar cell devices. It describes the mobilities, recombination rate and carrier densities that are functions of various other material properties and electrical excitation conditions in the electrical properties. The strong dependence on electrical properties and injection level can be used for contactless measurement of decisive solar cell properties. For this purpose, an accurate model for radiative recombination is important. The intrinsic recombination is the ""unavoidable"" contribution to the recombination rate related to fundamental physical mechanisms present even in perfect material quality. There are two different intrinsic recombination mechanisms: radiative and Auger recombination. The main loss contribution in common crystalline silicon solar cells is recombination via defects, mainly impurities within the crystal and surfaces. The defects essentially introduce energy states within the band‐gap, which provide a low‐energy pathway for electron‐hole pairs to recombine.