Impact of Non-Uniform Carrier Density on the Determination of Metal Induced Recombination Losses

We evaluate in detail the impact of sample properties on the accuracy of a simple area-weighted approach to determine the local dark saturation current density at metal contacts j0,met. Using metallized samples, we further compare the apparent j0,met resulting from this simple approach to the j0,met value determined using numerical simulations with Quokka3. The analysis shows that the assumption of a uniform carrier density of the area-weighted approach leads to a significant underestimation of j0,met which depends strongly on sample properties as e.g. the base resistivity rB and j0,met itself. This is confirmed by experimental data using conventional metallized samples, which demonstrate an underestimation of j0,met of up to 20% when using the area-weighted approach compared to numerical simulations.