It was recalled that polycrystalline material (cast ingot, ribbon), for solar cell manufacture, varied in behavior due to the effect of the various growth processes. The resultant microstructure and impurity content could influence material characteristics during heat treatment. As the gettering efficiency depended upon the type of polycrystalline material which was involved, the variations which were observed under optimum gettering conditions were considered. The effects of various methods of preparation of polycrystalline Si upon classical and rapid thermal process-induced P and Al co-diffusion were compared. It was shown that a large bulk minority carrier diffusion-length enhancement occurred in the case of co-diffusion, as compared with the separate diffusion of P and Al.

P/A1 Co-Gettering Effectiveness in Various Polycrystalline Silicon. K.Mahfoud, B.Pivac, J.C.Muller: Solar Energy Materials and Solar Cells, 1997, 46, 123-31