Two different electron beam-induced current methods were used to examine the diffusion of P at the grain boundaries. These were: imaging of the displacement of the pn junction at grain boundaries, and bright grain boundary contrast at low beam voltages. Solar cells on polycrystalline Si were used. Enhanced diffusion at grain boundaries was observed in 2 of 5 cells when using either of the above methods. One of the cells also exhibited enhanced diffusion at dislocations. It was found that there was a correlation between P diffusivity and an enhanced recombination activity at the grain boundaries.

K.Schimpf, J.Palm, H.Alexander: Crystal Research and Technology, 1994, 29[8], 1123-9