PLhenomenological model of grain-boundary trapping states in polycrystalline silicon under optical illumination

We have developed a new phenomenological model of grain boundary (GB) recombination, carrier transport and electrostatics under assumptions of Gaussian energy distributions of GB interface states, and unequal capture cross-sections of these GB states for electrons and holes in polycrystalline materials. Calculations have been performed of the recombination current density and the recombination velocity at grain boundaries in polycrystalline silicon for four different energy distributions. The results indicated that the recombination velocity at the grain boundary strongly depends on the location of the trap energy level. The assumption of GB interface states with a discrete (δ-function) distribution has been found to be inappropriate.