Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells

Ravishankar et al. claimed the drive-level capacitance profiling (DLCP) method cannot resolve trap density along depth direction in perovskites with given thickness, and explained the measured charges to be a consequence of geometrical capacitance and diffusion capacitance. We point out that the trap densities in DLCP method are derived from the differential capacitance at different frequencies, and thus the background charges caused by diffusion and geometry capacitance has been subtracted. Even for the non-differential doping analysis by DLCP, the contribution from diffusion capacitance is shown to be negligible and contribution from geometry capacitance is excluded. Additional experiment results further support the measured trap density represents the actual trap distribution in perovskite solar cells.