Study On Photoelectric Properties Of Doped Total Inorganic Cesium Lead Bromine Nanostructures

In recent years,organic-inorganic hybrid perovskite has been highly studied in the scientific community because of its advantages such as strong light absorption capacity,long carrier lifetime,high carrier mobility,and suitable and adjustable band gap.However,because it is easy to decompose at high temperatures,its application,in reality,has great limitations.All inorganic halide perovskite(CsPbX3)solves this problem by removing organic components,becoming a leader in the field of optoelectronic materials.Although CsPbX3 has many advantages,the toxicity of the Pb element affects its further use.In the past few years,researchers have found that it is possible to reduce the Pb ion content in CsPbX3 by doping with other metal ions,thus reducing its toxicity.However,there are also many problems in the selection of dopants,such as Sn2+ and Ge2+ as dopants,which are easy to be oxidized in air.Bi3+,In3+,Ln3+,and other trivalent ions can improve the performance of perovskite,but the doping efficiency is low.Bivalent ions such as Be2+,Mg2+,Ca2+,Sr2+,and Ba2+can increase the band gap and exciton binding energy of perovskite,but reduce its quantum yield.Recent studies have reported that some bivalent transition metal ions,such as Mn2+,Co2+,Ni2+,Cu2+,and Zn2+,play a crucial role in improving the luminescence properties of CsPbX3 nanocrystals.In this paper,aiming at the problems existing in the nanostructure of all-inorganic CsPbBr3 perovskite,the following work has been done to improve the photoelectric properties and structural stability of the materials by means of doping:1.The effect of manganese doping on the optical properties of CsPbBr3 was studied.Mn:CsPbBr3 nanocrystals with different Mn/Pb molar ratios were synthesized by the hot injection method.The results show that doping Mn2+ in CsPbBr3 nanocrystals can realize the change of CsPbBr3 emission from monochromatic to bicolor,and the two luminescence peaks are exciton luminescence peak and Mn2+ luminescence peak respectively.The luminescence range of the two peaks can be controlled by changing the Mn/Pb molar ratio.The decay life of PL varies greatly before and after Mn2+ doping.The lifetime of pure CsPbBr3 nanocrystals is ns class,while the lifetime of Mn-doped nanocrystals reaches ms class.2.Zinc-doped CsPbBr3 nanocrystals were prepared by hot injection method,and the effect of zinc doping on the optical properties of CsPbBr3 was studied.The results show that the introduction of zinc does not affect the monochromatic emission of CsPbBr3,nor does it change its morphology and structure.However,zinc addition has a great influence on the decaying life of PL.The PL attenuation lifetime of Zinc-doped nanocrystals is several times longer than that of pure CsPbBr3 nanocrystals.By changing the molar ratio of Zn/Pb,the wavelength range of luminescent peaks can be regulated to a certain extent and the quantum yield can be increased.CsPbBr3 nanocrystals doped with zinc and manganese were prepared by hot injection method.The optical properties of CsPbBr3 nanocrystals doped with zinc and manganese were studied.The results show that the co-doped CsPbBr3 with Zn and Mn has similar photoelectric properties to the CsPbBr3 nanocrystals with Mn or Zn alone.By changing the molar ratio of Zn,Mn,and Pb,the wavelength range of the luminescence peak can be regulated,and the luminescence intensity and stability can be increased.