Tailoring Photon Emission from CH3NH3PbBr3 Quantum Dots through Mn-Substitution

Developing strategies to modify lead-based metal halide perovskite lattice has become an increasingly important effort because of the need to control fundamental material properties. In this paper, we introduced a flow microreactor for the continuous synthesis of Mn-substituted methylammonium lead tribromide (CH3NH3Pb1–xMnxBr3) quantum dots. The original crystal structure can be retained at high Mn content (x = 0.3). The size and photoluminescence peak of the CH3NH3Pb1–xMnxBr3 quantum dots can be tuned by varying the molar ratio of Pb/Mn. With increasing Mn content, the photoluminescence peak shifted gradually to shorter wavelengths. Mn-substitution also affects the air stability for the quantum dots. CH3NH3Pb0.7Mn0.3Br3 shows the best air stability, and polystyrene can be used to protect the quantum dots. Compared to CH3NH3PbBr3 quantum dots, CH3NH3Pb1–xMnxBr3 quantum dots may prove to be a less toxic and valuable optoelectronic material meeting the requirements for different practical applications.