L. Jastrzebski et al., IMPROVEMENT OF DIFFUSION LENGTH IN POLYCRYSTALLINE PHOTOVOLTAIC SILICON BY PHOSPHORUS AND CHLORINE GETTERING, Journal of the Electrochemical Society, 142(11), 1995, pp. 3869-3872
Results of chlorine and phosphorus gettering of photovoltaic (PV) poly
crystalline silicon are presented. Using surface photovoltage (SPV) di
ffusion length (L) measurements, it has been established that PV polys
ilicon is very inhomogeneous and gettering only improves L values in r
egions in which L is relatively high and a large amount of nonprecipit
ated Fe and Cr is present. In regions with low L, nonprecipitated Fe a
nd Cr were not detected in as-grown polysilicon and gettering did not
cause any substantial improvement in L values. It is conceivable that
recombination in these regions is controlled by grown-in defects.