Numerical investigation of capacitance frequency technique for perovskite based solar cells

High efficiency perovskite based solar cells have attracted significant recent research interest. Capacitance frequency technique (CFT) has been used to characterize the defect density in such devices. However, the accuracy of estimated trap densities is not very well elucidated in the literature. Here we report detailed numerical simulations to explore the applicability of CFT technique for such devices. Our simulations indicate that there is significant band bending due to trapped charges and we introduce the concept of effective length approach for back extracting the trap density for such scenarios.