Efficient Carrier Separation and Intriguing Switching of Bound Charges in Inorganic-Organic Lead Halide Solar Cells

We fabricated a mesoporous perovskite solar cell with a similar to 14% conversion efficiency, and we investigated its beneficial grain boundary properties of the perovskite solar cells through the use of scanning probe microscopy. The CH3NH3Pb(I-0.88,Br-0.12)(3) showed a significant potential barrier bending at the grain boundary and induced passivation. The potential difference value in the x = 0.00 sample is similar to 50 mV, and the distribution of the positive potential is lower than that of the x = 0.12 sample. We also investigated the polarization and hysteretic properties of the perovskite thin films by measuring the local piezoresponse. Specifically, the charged grain boundaries play a beneficial role in electron hole depairing and in suppressing recombination in order to realize high-efficiency perovskite solar cells.