Synthesis of Sn-Doped CsPbBr3 Quantum Dot and Research on Its Photoelectric Properties

The Sn-doped CsPbBr3 quantum dots were synthesized by the hot injection method in this paper. The transmission electron microscope (TEM) and X-ray diffractometer (XRD) characterization results show that doping with a small amount of Sn can partially replace Pb and passivate the CsPbBr3 quantum dots, reducing the surface defects of quantum dots and improving the photoluminescence quantum yield (PLQY) of the quantum dots. Specifically, in the case of n(Pb):n(Sn)=9:1, the PLQY of the quantum dots is increased from 21.0% of the undoped CsPbBr3 quantum dots to 40.4% of the Sn-doped ones. However, with the rise in Sn content, some heterogeneous phases appear in the XRD patterns, the photoluminescene weakens, and the PLQY decreases from 40.4% of small amount of Sn-doped (n(Pb):n(Sn)=9:1) quantum dots to 10.4% of CsPb0.6Sn0.4Br3 quantum dots. In conclusion, CsPb0.9Sn0.1Br3 doped with a small amount Sn has the strongest photoluminescence and electroluminescence, with a photoluminescence peak at 511 nm, a PLQY of 40.4%, an electroluminescence peak at 512 nm, and an electroluminescence brightness of 343.0 cd/m(2) which is 2.5 times that of the undoped CsPbBr3 quantum dots. The experiments in this paper demonstrate that doping CsPbBr3 with a small amount of Sn (CsPb0.9Sn0.1Br3) can decrease the surface defects of quantum dots and improve the photoluminescence and electroluminescence properties of the quantum dots.