Determining the Generation Rate of Silicon Solar Cells from Reflection and Transmission Measurements by Fitting an Analytical Optical Model
A common task in silicon solar cell device modelling is fitting an optical model to measured reflection (and transmission) (R+T) spectra, in order to determine the device' generation rate for subsequent electrical modelling. The analytical light-trapping model introduced by Basore, also used in PC1D, and variants thereof, are often used for this task. This work investigates the accuracy of this approach, by checking the predicted generation resulting from R+T fits on experimental samples optically similar to industry standard PERC solar cells. We find that the simplest investigated model variant shows the overall highest accuracy of the generation current density better than 0.1 mA/cm², due to avoided generalizability errors of more complex models with more fitting parameters ("overfitting") with errors of up to 1 mA/cm².