A computer program for the characterization of solar cells

A quick and efficient computer program was developed in order to determine important parameters of solar cells, such as the series and shunt resistances, the ideality diode factor, the dark current, and the light current from I versus V measurements. A generalized, single‐exponential model was assumed and, instead of solving nonlinear equations, we used accurate analytical approximations for the calculation of the above parameters. The program was designed to be used easily on any IBM‐PC compatible computer by providing a user‐friendly interface. The required input parameters, such as the open circuit voltage (V_oc), short circuit current (I_sc), maximum power voltage (V_m), or maximum power current (I_m), were determined directly from the I–V pairs by numerical polynomial least‐squares fitting, so that the user does not have to determine these parameters graphically. Therefore, our program is also compatible with a data acquisition system attached to the same computer. The program was tested with simulated data and also with real measurements for typical production silicon solar cells; in all cases, good agreement between the experimental curve and the model’s theoretical curve was achieved as determined by a high correlation factor and also by the graphical comparison displayed by the program.