Efficient and Stable Self‐Trapped Blue Emission from a 1D Organolead Chloride Crystalline Material

Abstract Intrinsic blue emission with high stability and high efficiency remains to be a great challenge for metal halide hybrids. In this study, a single‐crystalline, ultrastable self‐trapped blue‐light emitter based on 1D cationic [Pb₂Cl₂]²⁺ haloplumbate chains is discovered, which affords a Stokes shift of 78 nm and Commission Internationale de l'Eclairage chromaticity coordinates of (0.156, 0.080), very close to blue standard (0.140, 0.080). The Stokes shift is the lowest reported value among the intrinsic self‐trapped emission from the vast majority of organometal halide hybrids. Moreover, the presence of out‐of‐plane chloride results in highly localized self‐trapped excitons in 1D cationic chains and high photoluminescence quantum yield of 72%, which exceeds many intrinsic blue‐light‐emitting metal halide materials. Analogous to the previously reported organocarboxylate‐based lead halide hybrids, the material exhibits ultrastable continuous photoemission in air for at least 24 h and maintains the efficient emission after a variety of thermal or chemical treatments. The excellent blue‐light‐emitting performance of the material enables its promising applications in high‐definition lighting and display fields.