Modeling majority carrier mobility in compensated crystalline silicon for solar cells

Carrier mobility in silicon plays a crucial role for photovoltaic applications. While the influence of doping on mobility in standard monocrystalline silicon is well understood, recent research has been focused on the effects of crystal defects in multicrystalline (mc) silicon and of the presence of both acceptors and donors in compensated silicon, both introducing additional scattering centers influencing carrier mobility. In this work measurements of the majority carrier mobility have been carried out in two blocks of compensated multicrystalline silicon. Confirming existing results we come to the conclusion that with increasing compensation level mobilities may be significantly lower than predicted by Klaassen's mobility model, which is basically suited for the description of mobilities in compensated silicon as it accounts for scattering on both acceptors and donors. However, as this model is based on mobility data from uncompensated silicon, a compensation-related reduction of screening is not taken into account sufficiently. To describe mobilities in compensated silicon, a modification of Klaassen's mobility model based on published mobility data in compensated silicon is suggested.

► We present mobility data and Hall factors in compensated multicrystalline silicon. ► We review and compare published mobility data in compensated silicon. ► We introduce a new approach for modeling mobilities in compensated silicon.