The dependence of barrier height and effective recombination velocity on the grain boundary theories in polycrystalline silicon

摘要

The important physical parameters, which characterise a grain boundary in polycrystalline silicon, are the barrier height and the effective recombination velocity at the grain boundary interface. Using Joshi's theory, we show in this paper the variation of these parameters with respect to grain doping for different energy distributions of grain boundary trap states. This work also demonstrates that the results established with the gaussian distribution of trap states, which is considered to be the exact distribution, can be easily obtained from the monoenergetic distribution. In fact, this distribution and Oualid's theory are used when the grain impurity concentration is superior to a value, which corresponds to the saturation of grain boundary trap states. However, this distribution is used with Joshi's theory when the impurity concentration is inferior to this value.