Effect Of Metal Ion Doping On Luminescence Properties Of CsPbCl₃ Perovskite Nanocrystals

In recent years,all-inorganic lead-halide perovskite nanocrystals（PNCs）have become one of the star materials in the field of optoelectronic devices.While significant progress has been made in the application of CsPbBr₃ and CsPbI₃ perovskite nanocrystals,the application of CsPbCl₃ perovskite nanocrystals is still limited by its weak luminescence,very low PLQYs（<0.5%）and instability under long-term exposure to oxygen and moisture.With the goal of improving the PLQY and stability of all-inorganic CsPbCl₃ perovskite nanocrystals.In this paper,it is proposed to improve the luminescence performance and stability of all-inorganic CsPbCl₃ perovskite nanocrystals by metal ion doping,and explores their doping mechanism and doping location.The main research contents are as follows:1.Using the trivalent cation(Er³⁺)of the rare earth metal element erbium as the B-position doping matrix,the Er³⁺doped CsPbCl₃ NCs(CsPbCl₃:Er³⁺)luminescent material with blue-violet emission was prepared.After optimizing the synthesis process,the highest photoluminescence quantum yield（PLQY）can reach 16.7%,the emission peak center was located at 400 nm,the full width at half maximum（FWHM）was 10.0 nm,the average particle size was about 7.98 nm.And the environmental stability is improved.After 10 days of storage at a temperature of 60℃ and a humidity of 60%RH,the luminescent material can still maintain more than 60%of the initial photoluminescence intensity,73%of initial fluorescence intensity after thermal cycling testing.2.The bivalent cation(Cu²⁺)and monovalent cation（Cu⁺）of the transition metal element copper were used as the B-site doping matrix,and the Cu²⁺and Cu⁺-doped blue-violet light emitting CsPbCl₃ NCs(CsPbCl₃:Cu²⁺and CsPbCl₃:Cu⁺)luminescent materials were prepared respectively.After optimizing the synthesis process,the luminescence performance and morphology structure of the two kinds of nanocrystals were measured separately,and the different effects of the two doping were found.The PLQY of CsPbCl₃:Cu²⁺at room temperature could reach 19.1%,the emission peak center was located at 410 nm,the FWHM was 9.96 nm,the average particle size was about 7.74 nm,and the environmental stability was improved,too.After 10 days of storage at a temperature of 60℃ and a humidity of 60%RH,the material can still maintain more than 70%of the initial photoluminescence emission intensity,80%of initial fluorescence intensity after thermal cycling testing;The PLQY of CsPbCl₃:Cu⁺at room temperature can reach 32.5%,the emission peak center was located at 410 nm,the FWHM was 9.83 nm,the average particle size was about 7.63 nm,and the environmental stability is significantly improved,and the material can still maintain more than 85%of the initial photoluminescence emission intensity after 10 days of storage in the environment of temperature 60℃ and 60%RH,80%of initial fluorescence intensity after thermal cycling testing.After characterization tests,it was found that Cu⁺doping entered the interior of the nanocrystals and the actual doping ratio was high,while the Cu²⁺doping only stayed on the surface,and it was speculated that the influence of the actual doping ratio on the luminescence performance was positively correlated,and whether it could enter the crystal lattice was positively correlated with the actual doping ratio.