Synthesis Of Metal Halide Perovskite And Their Applications In LED And Fluorescence Sensing

Metal halide APbX₃?A=CH₃NH₃⁺,CH?NH₂?₂⁺,Cs⁺;X=Cl^-,Br^-,I^-?perovskite nanocrystals?PNCs?have excellent photoelectric properties,such as high photoluminescence quantum yields?PLQYs?,narrow full width at half-maximum?FWHM?,high defect tolerance,precisely tunable bandgaps,and high carrier mobility.PNCs have shown excellent potential in terms of solar cells,light-emitting diodes?LEDs?,lasers,photocatalytic,and even analysis field.As one of the research topics in current materials,the development of PNCs is restricted by two factors,which is a large amount of toxic Pb²⁺in the structure and the poor stability of PNCs.In this article,beginning with reducing Pb²⁺and improve the stability of PNCs,and their applications were studied in LED devices and analysis field.The main results of our study were detailed as follows.?1?CsPb_xMn_1-xCl₃ PNCs were prepared by using multi-branched ligand TOPO and Mn organo-metal complex?Mn-TOPO?as the Mn²⁺reaction precursor through the high temperature hot-injection method.This material exhibited a higher Mn substitution ratio?up to 46%?,higher PLQYs?up to 56%?,better dispersibility,and outstanding stability.In addition,the CsPb_xMn_1-x-x Cl₃ PNCs exhibited a excellent performance as color conversion materials for bright orange LED devices with excellent thermostability.?2?Nano-SiO₂ with high chemical stability was chosen as the core layer material,and?3-Aminopropyl?triethoxysilane?APTES?as the organic ligand and hydrolysis material,the SiO₂@CsPbX₃@SiO₂ PNCs composites of monodisperse spherical sandwiched structure were prepared by high temperature hot-injection method.This material exhibit more excellent water-resistance while maintaining the original optical performance.Furthermore,the regular spherical structure of composites greatly benefit their application in relevant fields,and the SiO₂@CsPbX₃@SiO₂ PNCs composites were the excellent color conversion materials for the WLED device and demonstrated the commercial development prospect.?3?The HPbBr₃@PVDF fibers were obtained by encapsulating the HPbBr₃ crystals into electrospun poly?vinylidene fluoride?PVDF fibers via electrospinning technology.The fluorescent sensing for MA gas is realized through the conversion of HPbBr₃ crystals to MAPbBr₃ PNCs under the MA atmosphere.The detection limit of the MA sensor is as low as 0.8 ppm,and the detection process takes only about 20min.This method has high sensitivity and good reproducibility,and provides new ideas for the gas-solid synthesis of PNCs and broadening the application of PNCs in analytical detection.