Effect of illumination intensity on cell parameters of a silicon solar cell

The effect of illumination intensity P-in on the cell parameters of a silicon solar cell has been investigated based on one diode model. The variation of slopes of the I-V curves of a cell at short circuit and open circuit conditions with intensity of illumination in small span of intensity has been applied to determine the cell parameters, viz, shunt resistance R-sh, series resistance R-s, diode ideality factor n and reverse saturation current I-o of the cell. The dependence of cell parameters on intensity has been investigated for a fairly wide illumination intensity range 15-180 mW/cm(2) of AM1.5 solar radiations by dividing this intensity range into a desirable number of small intensity ranges for measurements of the slopes of the I-V curves at short circuit and open circuit conditions. Initially R-sh increases slightly with P-in and then becomes constant at higher P-in values. However, R-s, n and I-o all decrease continuously with P-in, but the rate of decrease of each of these becomes smaller at higher P-in values. Theoretical values of open circuit voltage V-oc, curve factor CF and efficiency eta calculated using the cell parameters determined by the present method match well with the corresponding experimental values. (C) 2010 Elsevier B.V. All rights reserved.