Ligand‐Controlled Formation and Photoluminescence Properties of CH₃NH₃PbBr₃ Nanocubes and Nanowires

Abstract Light‐emitting halide perovskites are currently emerging as promising solution‐processed materials for optoelectronic applications, and correlations between their physical properties and morphologies are important drivers to guide material and device optimization. There is still a lack of precise control of the morphology in colloidal perovskite materials, and in the related studies of their shape‐dependent optical properties. Capitalizing on our previous works on the ligand‐assisted reprecipitation synthesis of colloidal perovskite nanocrystals, we have addressed the role of key experimental parameters in determining the degree of supersaturation that drives the crystallization of CH₃NH₃PbBr₃ precursors. By adjusting the amount of ligands, we fabricated single crystalline CH₃NH₃PbBr₃ nanocubes (size: ≈500 nm) and nanowires (length: 2–4.5 μm, width: ≈100 nm), and conducted steady‐state, time‐resolved, excitation power and temperature‐dependent photoluminescence measurements to investigate their shape‐dependent photoluminescence properties.