Determination of diode parameters of a silicon solar cell from variation of slopes of the I-V curve at open circuit and short circuit conditions with the intensity of illumination

An analytical method of determination of all the four diode parameters of the single exponential model of a silicon solar cell, namely shunt resistance R_sh, series resistance R_s, diode ideality factor n and reverse saturation current I₀ from the variation of slopes of the I-V curve of the cell near short circuit and open circuit conditions with intensity of illumination in a small range of intensity, is presented for the first time. In a suitable range of intensity the variation of dI/dV at short circuit enables determination of R_sh, whereas the variation of dI/dV at open circuit enables determination of R_s, n and I₀. The diode parameters of a silicon solar cell were determined with this method using I-V characteristics of the cell in 40-125 mW cm^-2 intensity range of a simulated AM1.5 solar radiation. Theoretical I-V curves generated using so determined values of the diode parameters matched well with the experimental I-V curves of the cell obtained under various intensities of illumination in the above range.