Quantifying Surface Recombination - Improvements in Determination and Simulation of the Surface Recombination Parameter J0s

The recombination parameter J0s provides an important method to characterize surface recombination. For its calculation, numerous methods and models have to be applied. Since the models for the Auger and radiative recombination in crystalline silicon were recently revised, it is important to investigate the influence of these changes on J0s. The origin and possible ways of obtaining of J0s from effective lifetime measurements as well as simulations are described in detail, including the potential to fit the full lifetime curve and a new approach that is based upon the reparameterization of the excess charge carrier density Δn. Using effective lifetime measurements, we find that J0s-values determined with the older parameterization by Richter et al. will result in up to 10% erroneous values. By simulating the recombination parameter J0s in near-surface, highly-doped structures like emitters, it is shown that these errors can even go up to 50%. If used in a simulation, we highlight the importance of having the parameterizations of surface recombination being determined with the corresponding parameterization of intrinsic recombination. Therefore, an update for the recombination at oxide-passivated and phosphorous doped surfaces is given that can be used with the new intrinsic recombination models. Lastly, we give some best-practice examples on how recent improvements in effective lifetime measurements affect J0s values, as well as possible pitfalls.