Analysis of anomalies in current-voltage characteristics of silicon solar cells

The current-voltage characteristics of solar cells, under illumination and in the dark, represent a very important tool for characterizing the performance of the solar cell. The PC-ID computer program has been used to analyze the deviation of the dark current-voltage characteristics of p-n junction silicon solar cells from the ideal two-diode model behavior of the cell, namely the appearance of "humps" in the I-V characteristics. The effects of the surface recombination velocity, the minority carrier lifetimes in the base- and emitter regions of the solar cell, as well as the temperature dependence of the I-V characteristics have been modeled using PC-ID. It is shown that the humps in the I-V characteristics arise as a result of recombination within the space-charge region of the solar cell, and occur when conditions for recombination are different from the simple assumptions of the Shockley-Read-Hall theory.