A three-dimensional model has been developed for cathodoluminescence contrast of localized defects in semiconductors. The numerical model incorporates electron-solid interaction effects, charge transport phenomena and optical losses. Electron-solid interaction is modelled by a Monte Carlo method. Three-dimensional continuity equation and derivative boundary conditions are discretized by a central-difference quotients scheme. Localized defects are represented by regions of enhanced non-radiative recombination. The discretized linear difference equations of the boundary value problem are solved by the successive-over-relaxation method. A method for avoiding the divergence problem during the successive-over-relaxation calculation is illustrated. The solutions of the model are compared with the analytical results of several established models
