Analysis of Electrical Properties of Grain Boundaries in Polycrystalline Silicon Solar Cell Using Laser Beam Induced Current

Abstract

We have investigated the effect of grain boundaries on a polycrystalline solar cell using laser beam induced current (LBIC). We have successfully evaluated the two-dimensional minority carrier diffusion length, which is one of the most important parameters, in order to fabricate high-efficiency polycrystalline solar cells. Based on the carrier lifetime, the numerical recombination velocity at the grain boundaries was obtained. The change of the recombination velocity by the gettering effect was also clarified. We have confirmed that the recombination velocity is improved by the gettering treatment from 2×104–5×104 cm/s to 3×103–7×103 cm/s.