Determination of solar cell equation parameters from empirical data

The determination of the solar cell equation parameters (I–V characteristic) from experimental data was achieved by the least square method, where all data points were considered. The five parameters of the cell equation were transformed to a three parameter equation, resulting in a simplified solution. In the fitting procedure of the calculated I–V characteristic to the experimentally measured points, the errors of the instrumentation were taken into account. The shunt resistance appeared to be important for a desired fitting accuracy.