Optimizing Black Phosphorus/Halide Perovskite Compositions by Scanning Photoelectrochemical Microscopy

The incorporation of black phosphorus (BP) into methylammonium lead iodide (MAPbI 3 ) perovskites has been investigated and optimized by a high throughput screening method using scanning photoelectrochemical microscopy (SPECM) to determine how the addition of BP affects its photoelectrochemical and photovoltaic properties. An optimum ratio of 2.0 mole% BP/MAPbI 3 perovskite composite generates an increased photocurrent response compared to pristine MAPbI 3 for 2 mM benzoquinone (BQ) reduction at −0.6 V vs Ag/AgNO 3 on a spot array electrode under illumination. Due to the relatively high quantum yield of MAPbI 3 , time-resolved photoluminescence measurements have been conducted to investigate photophysical behaviors of BP/MAPbI 3 composites. The optimal 2.0 mole% BP/MAPbI 3 exhibits an increased electron-hole diffusion lifetime compared to the pristine MAPbI 3 perovskite. Finally, we demonstrate the enhanced efficiency and stability of 2.0% BP/MAPbI 3 -based perovskite solar cells arising from impeded Pb 0 -defect generation and suppressed charge-carrier recombination.