Highly Tunable Photoluminescence of Wide-Bandgap Lead-ChloridePerovskite Single Crystal Based on Ion Beam Irradiation

Mixed halide perovskite encounters an instability issue in light-emitting applications due to phase segregation. It remains intriguing to tune the emission spectral shape of perovskites with a single halide composition. The deep defects of wide-bandgap lead-chloride perovskites introduce extra radiative recombination channels and can be used to realize emission tuning. In this work, we induce defects into the localized regions of MAPbCl₃ (MA = CH₃NH₃) single crystal by utilizing a focused probe of high-energy, small mass ion irradiation (500 keV He⁺) of different fluences. Our results show that the selected ion irradiation probe can induce controllable knock-on displacement and radiolysis, which generate defects in the perovskite lattice and modulate the relative intensity of intrinsic and sub-band gap emissions efficiently in a wide range of 3.05–1.6 eV. Our work demonstrates a promising strategy for efficient tuning of the local emission on a single halide perovskite crystal and paves the way for pixelated multicolor emission applications.