Irradiance-dependence and translation of the I-V characteristics of crystalline silicon solar cells

The current-voltage characteristics I_out(V) of crystalline silicon (c-Si) solar cells are experimentally investigated at various irradiance E. Its dependence on E can be well approximated by the sum of a dark current and a voltage-dependent “photocurrent”, which is proportional to E. These results are used to develop translation equations. It is demonstrated that the resulting formula is able to calculate the I_out(V) of c-Si solar cells at any E from experimental I_out(V) at two different Es, with comparable or better accuracy than the conventional procedure based on the shifted approximation. The present procedure is straightforward, and does not require correction for the series resistance. The same procedure is valid for various solar cells including a-Si, thin-film crystalline silicon, and CdTe