Enhanced Exciton-to-Mn2+ Energy Transfer in 3D/0D Cesium–Lead–Chloride Composite Perovskites

Doping cesium lead halide perovskite nanocrystals (NCs) with Mn 2+ brings attractive long-wavelength emission and flexible color tunability. However, due to multiple competing factors, the exciton-to-Mn 2+ energy transfer efficiency is low. In this work, a simple structure-optimization strategy is applied to enhance the exciton-to-Mn 2+ energy transfer by synthesizing Mn 2+ activated 3D/0D Cs–Pb–Cl perovskite composition composed of 3D CsPbCl 3 and 0D Cs 4 PbCl 6 NCs. The results reveal that the energy transfer efficiency and the photoluminescence quantum efficiency of the Cs–Pb–Cl composite are 65.3% and 77.3%, respectively, which are 1.4 and 3 times the corresponding values of the single-phase CsPbCl 3 :Mn 2+ NCs. Based on the detailed experimental and calculation results, the performance enhancement is demonstrated to stem from the optimized growth process of 3D CsPbCl 3 NCs when co-generating with 0D Cs 4 PbCl 6 NCs. The strong lattice rigidity of the optimized CsPbCl 3 NCs suppresses the nonradiative combination rate of the excitons, thus alleviating the main competing factor of the energy transfer process and improving the energy transfer efficiency. Fabrication of a white light-emitting diode prototype further illustrates the application potential of the orange-emitting Cs–Pb–Cl composite NCs for general lighting.