Synthesis And Ultrafast Dynamics Of Perovskite-like Luminescent Materials Based On CsNiCl₃

Over the past few years,perovskite materials have been widely used in solar cells,photodetectors,lasers,light emitting diode and other fields due to their excellent optical properties.Lead-based perovskites have excellent performance,but the toxicity of lead will affect the environment and human health.Therefore,finding a substitute for lead to synthesize new non-toxic perovskite materials has been a hot spot in the perovskite field in recent years.All-inorganic zero-dimensional metal halide perovskites have recently received more and more attention due to their excellent photoluminescence（PL）and high stability.Its nanocrystalline perovskite has high crystallinity and high exciton binding energy.At the same time,the nanometer size will bring quantum confinement effects.In this dissertation,CsNiCl₃perovskite nanocrystals were synthesized for the first time by thermal injection.In previous studies,CsNiCl₃ perovskite was only reported as a single crystal.After synthesizing the CsNiCl₃ nanocrystals,the method of adding Cu⁺to the precursor was used to make the CsNiCl₃ nanocrystals without photoluminescence phenomenon present a green emission peaked at 530 nm,with a PL quantum yield of 7%（PLQY）.It was also found that during the synthesis process,the divalent copper ions in the precursor were reduced to monovalent copper ions under the action of oleylamine.Subsequently,inspired by the double perovskite,the PLQY was increased from 7%to 42%through the co-doping of Cu⁺and In³⁺while the emission peak position of the CsNiCl₃nanocrystals remains unchanged.This dissertation explored the involved dynamics of CsNiCl₃nanocrystals co-doping with Cu and In as well.Finally,RbNiCl₃ nanocrystals were synthesized by changing the A-site cation,and Cs Ni Br₃nanocrystals were synthesized by changing the halogen elements at the X position,under the co-doping of Cu and In ions,they showed orange luminescence with a peak at 600nm.So far,this dissertation has successfully synthesized tunable（green,orange）perovskite-like nanocrystalline materials based on Cs Ni X₃.