Abstract:

In order to reduce the Pb²⁺ toxicity of CsPbBr₃ perovskite nanocrystals and optimize the luminescent performance of Sn²-doped CsPbBr₃ nanocrystals，Sn²⁺-doped CsPb_1-x Sn _x Br₃ nanocrystals（x=0.1，0.2，0.3，0.4 and 0.5） were synthesized by hot-injection method. The phase structure，microstructure and luminescent performance of the synthesized nanocrystals were characterized by X-ray diffractometer（XRD），transmission electron microscope（TEM），X-ray photoelectron spectroscopy（XPS），and photoluminescence spectrometer（PL）.The results showed that CsPb_1-x Sn _x Br₃ nanocrystals existed in the form of Sn²⁺ and Sn⁴⁺ ions，and contained Pb²⁺ cation vacancies. When x=0.3，the actual molar doping concentration of Sn element was as high as 43.91%. When x=0.1~0.4，the nanocrystals structure was pure monoclinic perovskite，the size was about 16~20 nm，and the square shape was uniform.The spectral properties of CsPb_1-x Sn _x Br₃ nanocrystals were regulated by Sn²⁺-doped. When x=0.3，the fluorescence emission peak of CsPb_1-x Sn _x Br₃ nanocrystals was located at 523 nm，the full width at half maxima（FWHM） was 15 nm，the fluorescence lifetime was as long as 86.3 ns，and the fluorescence intensity was the strongest，which were a kind of excellent green-light emitted semiconductor materials with potential application.

Key words: Sn²⁺-doped, CsPb_1-x Sn _x Br₃ nanocrystals, monoclinic perovskite, luminescent performance