Shunt resistance and saturation current determination in CdTe and CIGS solar cells. Part 1: a new theoretical procedure and comparison with other methodologies

A new proposal for the extraction of the shunt resistance (R _sh) and saturation current (I _sat) of a current-voltage (I–V) measurement of a solar cell, within the one-diode model, is given. First, the Cheung method is extended to obtain the series resistance (R _s), the ideality factor (n) and an upper limit for I _sat. In this article which is Part 1 of two parts, two procedures are proposed to obtain fitting values for R _sh and I _sat within some voltage range. These two procedures are used in two simulated I–V curves (one in darkness and the other one under illumination) to recover the known solar cell parameters R _sh, R _s, n, I _sat and the light current I _lig and test its accuracy. The method is compared with two different common parameter extraction methods. These three procedures are used and compared in Part 2 in the I–V curves of CdS-CdTe and CIGS-CdS solar cells. (paper)