Modeling of the surface sulfurization of CIGSe-based solar cells

The modeling of the effect of absorber surface sulfurization on state-of-the-art CIGSe-based solar cells is studied using the 1 dimensional modeling tool SCAPS 3.2. The evolution of the photovoltaic performance of the cell is modeled for different sulfur contents and sulfurization depth; these parameters are simultaneously varied to obtain a representation of the ideal conditions which maximize the solar cell efficiency. Different interface defect types are considered and the influence of the S atoms on the interface defects activation energy, as well as on the majority carrier concentration in the CIGSe film, is taken into account in our model. Most of the modeling parameters are determined from in-house measurements, especially concerning the evolution of the interface defects with the surface sulfurization.