Nanoscale Plasmonic Heating-Induced Spatiotemporal Crystallization of Methylammonium Lead Halide Perovskite

Precise spatiotemporal control over crystallization is essential for advancing optoelectronic materials, yet achieving this in lead halide perovskites remains challenging. Conventional methods rely on preseeded growth, suffer from redissolution, or require complex optical setups. Here, we demonstrate a seed-free, plasmonic heating-driven approach for nanolocalized, on-demand nucleation and growth of methylammonium lead bromide (MAPbBr₃) perovskites using a continuous-wave (CW) laser. By leveraging localized surface plasmon resonance (LSPR) in gold nanoparticles (AuNPs), we induced supersaturation at the NP surface to initiate crystallization. Using high-speed microscopy, we captured subsequent critical events from nucleation to growth with submillisecond resolution. These insights challenge conventional crystallization models and establish a scalable, mask-free platform for engineering perovskite materials with tailored properties for next-generation optoelectronics.