Preparation And Properties Of A New Non-Lead Chalcogenide Phosphor Doped With Transition Metal/Rare Earth Ions In Cs₂MnCl₄

Lead halide perovskite,as a revolutionary photoelectric semiconductor material,has been widely concerned,and its superior photoelectric properties have attracted more and more attention in recent years.However,due to the toxicity and stability of Pb,its application in real life is limited.All-inorganic lead-free halide perovskite has many advantages,such as eliminating lead toxicity,being more stable in properties and having unique photoelectric characteristics.It has become the most promising photoelectric material at present,and has been widely used in various fields.For example,perovskite photoelectric materials can be used in light-emitting diodes（LEDs）,perovskite films,solar cells,photodetectors and X-ray detectors.In order to further study lead-free halide perovskite materials,the following aspects are studied in this paper for Mn-based halides:1、This passage describes a new type of fluorescent powder,2D non-lead halide Cs₂MnCl₄:Cu⁺,as a white light emitting diode（LED）.Copper（I）was introduced into Cs₂MnCl₄through solid-phase reaction,which showed a strong green emission with 70%photoluminescence quantum yield（PLQY）.The emission center was at 530 nm and the optimal excitation wavelength was determined to be 310 nm,indicating a large Stokes shift of 220 nm.Steady-state and transient fluorescence spectra showed a decay time of 114.19μs,indicating the self-trapped exciton（STE）emission mechanism.This work demonstrates that halide manganese can be considered as a new family of high-efficiency optoelectronic applications..2、By doping EuCl₃ into Cs₂MnCl₄ through solid phase reaction,lead-free perovskite materials with white light emission were prepared by adjusting temperature and reaction time.XRD,SEM,EDS,PL and other methods were used to study the structure and luminescence properties.The emission of Eu-doped Cs₂MnCl₄ originates from the transitions of Mn²⁺(⁴T_1g→⁶A_1g)within the 3d⁵ configuration and Eu²⁺4f⁶5d¹→4f⁷ transitions.Furthermore,WLEDs with a color rendering index of and 80,and color coordinates of and（0.3087,0.2779）were obtained by packaging the chips with 400 nm,which meets our daily lighting needs.