Monte Carlo simulation of charge carriers' trapping in polycrystalline semiconductors

Kinetics of charge carriers' trapping in polycrystalline semiconductors during thermally stimulated conductivity (TSC) and thermoluminescence (TL) processes was studied. Numerical calculations were performed using Monte Carlo method. It was found that the simple trap model and general order kinetics model commonly used for the description of TL and TSC are not appropriate for polycrystalline solids. The shapes of TL and TSC spectra depend strongly on the size of grains especially in the case of low concentrations of deep trapping states and high retrapping coefficients. The limiting cases in which classical differential equations are valid were found. Using generalised Monte Carlo algorithm the effect of external electric field on thermally stimulated relaxation spectra was studied.