Stabilizing Metal Halide Perovskite Films via Chemical Vapor Deposition and Cryogenic Electron Beam Patterning

Halide perovskites are hailed as semiconductors of the 21st century. Chemical vapor deposition (CVD), a solvent‐free method, allows versatility in the growth of thin films of 3‐ and 2D organic–inorganic halide perovskites. Using CVD grown methylammonium lead iodide (MAPbI3) films as a prototype, the impact of electron beam dosage under cryogenic conditions is evaluated. With 5 kV accelerating voltage, the dosage is varied between 50 and 50000 µC cm−2. An optimum dosage of 35 000 µC cm−2 results in a significant blue shift and enhancement of the photoluminescence peak. Concomitantly, a strong increase in the photocurrent is observed. A similar electron beam treatment on chlorine incorporated MAPbI3, where chlorine is known to passivate defects, shows a blue shift in the photoluminescence without improving the photocurrent properties. Low electron beam dosage under cryogenic conditions is found to damage CVD grown 2D phenylethlyammoinum lead iodide films. Monte Carlo simulations reveal differences in electron beam interaction with 3‐ and 2D halide perovskite films. Cryogenic e‐beam patterning of chemical vapor deposited methylammonium lead iodide films enhances the photoluminescence and the photocurrent properties due to a reduction in the defect density of the surface. Unlike 3D halide perovskite films, 2D perovskites have a reduced damage threshold towards e‐beam irradiation. Monte Carlo simulations reveal differences in electron beam interaction with 3‐ and 2D halide perovskite films.