Optical and Magnetotransport Characterisation of Solar-Grade mc-Silicon Wafers

Multicrystalline silicon (mc-Si) wafers from different suppliers have been characterized combining optical and transport measurements. Using several optical techniques, namely spectroscopic ellipsometry and optical absorption, together with magneto-transport measurements such as Hall density and mobility, resistance and capacitance, and their temperature dependence, one can obtain very precise information about main physical parameters such as electronic density, mobility, real and complex refractive index, absorption coefficient and strains on the grain boundaries. This preliminary study, based on two different physical approaches, aims to qualify wafer suppliers on the basis of several non-conventional properties of mc-Si wafers that can be of crucial interest to complete the scarce information usually included in the classical wafer manufacturer’s datasheet. Thus, this type of characterization can be considered as crucial for solar cells producers, as a first quality control step.