High-Efficiency Fast-Radiative Blue-Emitting Perovskite Nanoplatelets and Their Formation Mechanisms

High-efficiency blue perovskite emitters with fast fluorescence radiation are not only crucial to achieving high-quality displays but also highly desired for optical wireless communications and quantum information technologies. Here, we demonstrate the preparation of blue-emitting Eu³⁺-, Sb³⁺-, and Ba²⁺-induced CsPbBr₃ nanoplatelets with narrow spectral widths. Among them, Sb³⁺-doped CsPbBr₃ NPLs can reach a photoluminescence quantum yield of 95%, with a very short fluorescence lifetime of 1.48 ns and greatly reduced ligand dosage. Through nuclear magnetic resonance analysis and density functional theory calculations, we find that the dopant–ligand interaction and dopant-induced growth energy barrier decide the growth kinetics of doped nanoplatelets. These mechanisms offer a fresh route to controlling the dimension of nanoscale perovskite emitters and benefit the development of fast-radiative perovskite emitters.