LaCl ₃ -doped MAPbBr ₃ nanocrystals for stable blue emission

Abstract In past few years, significant advances have been achieved in the development of green and red-light emitting perovskite halide nanocrystals (NCs). But in comparison, the performance of blue light-emitting perovskite NCs is not satisfactory. In this work we successfully synthesized La 3+ and Cl − doped MAPbBr 3 NCs by simple ligand-assisted reprecipitation technique to achieve stable blue light emission. Here, we concomitantly realized the doping of La 3+ into the MAPbBr 3 NC system at two different concentrations and also regulated the Cl/Br ratio by introducing a controlled amount of LaCl 3 to the reaction mixture. Our study is the first to investigate the doping of La 3+ ions into MAPbBr 3 NCs and examine their optical properties. The La 3+ doping maintains structural integrity without inducing phase changes. Temperature-dependent photoluminescence studies reveal higher exciton binding energy, contributing to improved luminescence stability. The La 3+ doping shows a faster nucleation process leading to reduced NC size and also an increase in shallow defect states. This is further explained in time-resolved photoluminescence studies. The La 3+ -doped NCs exhibit blue emission centred at 470 nm, covering 92.61% of the Rec 2020 colour space, offering a promising, cost-effective alternative for next-generation blue light-emitting materials in display applications.