A numerical simulator for graded-bandgap solar cells

A one-dimensional semiconductor simulator is implemented. This simulator is able to simulate thin film graded-bandgap semiconductors having position dependent device parameters such as: the energy gap, absorption coefficient, the dielectric constant and other parameters. The simulator is able to calculate the conversion efficiency of the solar cells under normal conditions as well as the limiting efficiency of the cells. It calculates the efficiency by solving the coupled semiconductor equations, namely, Poisson's equation and the current continuity equations together with the Boltzmann photon equation. The non-avoidable bulk losses due to carriers recombination, namely, radiative and Auger, are carefully considered. The photon-recycling effect is carefully taken into account.