Evaluation of luminescence images of solar cells for injection-level dependent lifetimes

If the minority carrier lifetime in a semiconductor is dependent on the injection level, the dark current–voltage characteristic of solar cells may show an ideality factor n1 larger than unity. This modifies the evaluation of photoluminescence and electroluminescence imaging data for obtaining the distribution of the local series resistance and saturation current density of solar cells. In this contribution these modifications are summarized and applied to an iterative method for evaluating electroluminescence images. It is found that even a small increase of n1 leads to substantial variations of the resulting series resistance values.