Regulation And Optimization Of The Luminescence Performance Of The Bromine-lead-cesium Perovskite WLED

White Light Emitting Diode?WLED?as the fourth-generation solid lighting source,because of its outstanding economic and technical advantages in environmental protection and performance,shows a broad application prospect.As the core working material for realizing white light emission,the development of a green phosphor with strong fluorescent ability and stable physicochemical properties has important practical significance for the development of three primary colors WLED.In this work,the bromine lead cesium perovskite?Cs₄PbBr₆/Cs PbBr₃?material,which has been widely studied in recent years,is selected as the research object.Although this type of material has excellent photoelectric properties,when it is used in the preparation of WLED,the discussion and research on the influence of the incorporation ratio of materials,working time,working temperature,and driving current the device performance are not clear.In this work,the room-temperature self-assembly method is used to synthesize the bromine lead cesium perovskite phosphor.This method has a short synthesis time,cheap raw materials,and a maximum yield of 86.2%.UV-Vis absorption analysis shows that it has a high absorption capacity in the blue region,so it can be excited by the blue device.The photoluminescence spectrum at room temperature shows that the emission peak of this material is at 521 nm and has excellent monochromaticity.Variable temperature fluorescence analysis indicates that the phosphor has a large exciton binding energy,revealing a higher thermal stability.Green LED was prepared using this phosphor and variable current tests showed that the color stability of the device was very high,and its color coordinates hardly changed within the range of 5-30 m A.These above phenomena are beneficial to produce white light with stable performance.The bromine lead cesium material exhibits attractive characteristics and has been used in lighting equipment.Based on its coating with K₂Si F₆:Mn⁴⁺?KSF?red powder on blue LED,white light-emitting diode devices have been manufactured.The effects of operating current,operating time and operating temperature on the device's luminous efficiency,color rendering index,correlated color temperature and color coordinate are systematically studied.The data shows that these factors play an important role in the conversion of phosphor to white light illumination.The performance index of the device was optimized,the color rendering index and color coordinate are up to 83.6,?0.3392,0.3336?or?0.3379,0.3369?respectively,showing good color reproduction and white light characteristics,and the optimized luminous efficiency reaches 65.33 lm/W.In addition,by controlling the metering ratio of red powder to bromine lead cesium perovskite,warm white light,positive white light,and cold white light devices were prepared separately.These conclusions prove that the bromine lead cesium perovskite phosphor has great potential and is expected to become a traditional phosphor substitute for low-cost and high-quality white light sources in the next-generation white lighting technology.