Reduction in the Interfacial Trap Density of Mechanochemically Synthesized MAPbI₃

Organo-lead halide perovskites have emerged as promising light harvesting materials for solar cells. The ability to prepare high quality films with a low concentration of defects is essential for obtaining high device performance. Here, we advance the procedure for the fabrication of efficient perovskite solar cells (PSCs) based on mechanochemically synthesized MAPbI 3 . The use of mechano-perovskite for the thin film formation provides a high degree of control of the stoichiometry and allows for the growth of relatively large crystalline grains. The best device achieved a maximum PCE of 17.5% from a current–voltage scan ( J–V ), which stabilized at 16.8% after 60 s of maximum power point tracking. Strikingly, PSCs based on MAPbI 3 mechanoperovskite exhibit lower “hysteretic” behavior in comparison to that comprising MAPbI 3 obtained from the conventional solvothermal reaction between PbI 2 and MAI. To gain a better understanding of the difference in J–V hysteresis, we analyze the charge/ion accumulation mechanism and identify the defect energy distribution in the resulting MAPbI 3 based devices. These results indicate that the use of mechanochemically synthesized perovskites provides a promising strategy for the formation of crystalline films demonstrating slow charge recombination and low trap density.