Sculpting the Electronic\nNano-Terrain on a Perovskite\nFilm for Efficient Charge Transport

Nanopatterned halide perovskites have emerged to improve\nthe performance\nof optoelectronic devices by controlling the crystallographic and\noptical properties via morphological modification. However, the correlation\nbetween the photophysical property and morphology transformation in\nnanopatterned perovskite films remains elusive, which hinders the\nrational design of nanopatterned halide perovskites for optoelectronic\ndevices. In this study, we employed nanoimprinting lithography on\na perovskite film to exert a precise control over grain growth and\nmanipulate electronic structures at the level of individual grains.\nSurface-selective fluorescence lifetime imaging microscopy (FLIM)\nanalyzes the spatiotemporally disentangled geometrical variations\nin carrier recombination rate and band structure modulation according\nto different pattern morphologies. Consequently, the stereoscopic\nmechanism of confined grain growth was unveiled, highlighting the\nquantitative grain size-based parameters that are crucial for nanoscale\nmaterial engineering. Notably, the pattern-induced reduction of effective\ncharge mass enabled exclusive control over the subdiffusive carrier\ntransport dynamics on perovskite surfaces, ultimately realizing the\nsurface-selective perovskite photodetectors. The implications of this\nstudy are expected to provide valuable guidelines, inspiring innovative\ndesign protocols for advancing the next-generation optoelectronic\ntechnologies.