Energy Yield Modeling of Perovskite–Silicon Tandem Photovoltaics: Degradation and Total Lifetime Energy Yield

Abstract

This study investigates the impact of degradation in perovskite-silicon tandem solar cells by means of energy yield (EY) modelling over the entire lifetime. First, we assess the impact on EY of degradation in the individual solar cell parameters of the perovskite top cell. Our analysis reveals that degradation in fill factor, due to a decline in perovskite top cell shunt resistance (RSh), has the most severe impact on the EY, emphasizing the imperative to rectify perovskite imperfections in thin film processing causing RSh decline. Second, we investigate implications of degradation in the perovskite top cell on the EY of current mismatched tandem solar cells. Third, we examine critical thresholds for the “acceptable degradation levels” in the perovskite top cell with regard to degradation in each solar cell parameter, assuming that the total loss in EY must be comparable to the degradation in state-of-the-art silicon. Overall, our study highlights that degradation of the perovskite top cell needs to be assessed with care when extrapolating the impact on the lifetime EY of perovskite-silicon tandem solar cells. The severity of degradation for different degradation mechanisms in a single junction perovskite solar cell cannot be translated one-to-one to tandem devices.