Numerical simulation of defects in III-V PV cells: the effect of voltage bias and doping concentration

The presence of defects in a solar cell device affects the electrical parameters causing possible performance deterioration. Point-like defects are expected to have significant impact on their local surroundings. Their effect weakens away from them. For this reason a physical model of a GaAs device taking into consideration the impact of local ohmic shunts was developed in order to examine the effect of the shunts on the electrical and physical parameters. Defect states have been treated as degenerate semiconductors and the impact of voltage bias and degeneracy on the main electrical parameters of the cell have been investigated.