Imaging Surface Recombination Velocities of Grain Boundaries in Multicrystalline Silicon Wafers via Photoluminescence

Abstract

We present a method for determining the effective surface recombination velocity (SGB) of grain boundaries in silicon wafers, based on the photoluminescence contrast of the grain boundary and numerical modeling of the luminescence signal. It is found that in single‐side passivated wafers, the luminescence contrast of a grain boundary is insensitive to lifetime variations in the neighboring grains, and hence can be directly correlated to SGB. In combination with pattern recognition methods to locate the grain boundaries, this allows the SGB of every grain boundary within a photoluminescence image to be explicitly determined and imaged.