Ultrasmall 2D Sn‐Doped MAPbBr3 Nanoplatelets Enable Bright Pure‐Blue Emission

Abstract

AbstractSynthesis of perovskites that exhibit pure‐blue emission with high photoluminescence quantum yield (PLQY) in both nanocrystal solutions and nanocrystal‐only films presents a significant challenge. In this work, a room‐temperature method is developed to synthesize ultrasmall, monodispersed, Sn‐doped methylammonium lead bromide (MAPb1‐xSnxBr3) perovskite nanoplatelets (NPLs) in which the strong quantum confinement effect endows pure blue emission (460 nm) and a high quantum yield (87%). Post‐treatment using n‐hexylammonium bromide (HABr) repaired surface defects and thus substantially increased the stability and PLQY (80%) of the NPL films. Concurrently, high‐precision patterned films (200‐µm linewidth) are successfully fabricated by using cost‐effective spray‐coating technology. This research provides a novel perspective for the preparation of high PLQY, highly stable, and easily processable perovskite nanomaterials.