Investigation of Recombination Parameters of Nonequilibrium Charge Carriers in Si Technological Plates by Thermal Imaging Method

Abstract

The research approach on the investigation of recombination parameters of nonequilibrium charge carriers in Si technological plates by thermal imaging method is offered in this paper. The lifetime, diffusion length and surface recombination velocity of charge carriers are taken into account. The method is based on a study of the spatial distribution of Si samples thermal radiation beyond the self-absorption edge in the spectral range of 3–5 μm using by an IR camera. There are experimental results of silicon technological samples researches: distribution of the excess charge carriers concentration in silicon samples (n-Si, ρ = 500 Ω⋅cm, d = 8 mm) and the diffusion distribution of charge carriers at T = 150 °C. Temperature dependence of the diffusion length and volumetric lifetime in silicon samples is measured by three different methods: using an IR camera, by the kinetics of thermal radiation decline beyond the self-absorption edge during laser excitation, and by the method of photoconductivity attenuation. This approach is implemented in the process of input control of silicon plates used for solar panels manufacture at JSC “Quasar.”