Microstructure‐Assisted Wafer‐Scale Fabrication of Perovskite Microlaser Arrays

All inorganic lead halide perovskites exhibit fascinating optical and optoelectronic characteristics for on‐chip lasing, but the lack of precise control of wafer‐scale fabrication for perovskite microstructure arrays restricts their potential applications in on‐chip‐integrated devices. In this work, a microstructure‐template assisted crystallization method is demonstrated via a designed chemical vapor deposition process, achieving the controllable fabrication of homogeneous perovskite micro‐hemispheroid (PeMH) arrays spanning the entire surface area of a 4‐inch wafer. Benefiting from the low‐loss whispering gallery resonance and plasmon‐enhanced light‐matter interactions in well‐confined hybrid cavities, this CsPbX 3 /Ag (X = Cl, Br) plasmonic microlasers exhibit quite low thresholds below 10 µJ cm −2 . Interestingly, these thresholds can be efficiently modulated through the manipulation of plasmonic resonance and electromagnetic field mode in PeMHs owning various diameters. This strategy not only provides a valuable methodology for the large‐scale fabrication of perovskite microstructures but also endorses the potential of all‐inorganic perovskite nanostructures as promising candidates for on‐chip‐integrated light sources.