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 Eu 3+ -, Sb 3+ -, and Ba 2+ -induced CsPbBr 3 nanoplatelets with narrow spectral widths. Among them, Sb 3+ -doped CsPbBr 3 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.