Improved ultraviolet radiation stability of Mn2+-doped CsPbCl3 nanocrystals via B-site Sn doping

Abstract

Enhancing the highly ultraviolet irradiation stability of luminescent Mn²⁺-doped all-inorganic halide perovskite nanocrystals (NCs) is challenging because their optical properties depend on their ionic structure and its inherent defects. Herein, we presented a facile and effective synthesis method using a B-site Sn doping strategy to grow Mn²⁺-doped CsPbCl₃ (Mn:CsPbCl₃) NCs with enhancement in ultraviolet irradiation stability and emission efficiencies. Mn:CsPbCl₃ NCs were prepared by tailoring the amount of SnCl₂ added during the growth of NCs. The element and microstructure analysis revealed that the Sn ions were successfully doped into the host NC lattice and had the valence state of +2. With the increase in the Sn doping content, the doping efficiency of the Mn²⁺ ions increased and the photoluminescence (PL) intensity of NCs was enhanced. The optimum synthesis of Mn:CsPbCl₃ NCs was obtained at an Sn/Mn/Pb molar ratio of 1/1/1, and the PL quantum efficiency reached 43%. More importantly, on increasing the ultraviolet illumination time, almost unchanged single exponential decay times of the Mn²⁺ emissions and slow reduction in the PL intensities of Mn:CsPbCl₃ NCs were found after Sn doping, indicating that Sn doping can significantly improve the ultraviolet irradiation stability of Mn:CsPbCl₃ NCs.