研究了不同Mn/Pb量比的Mn掺杂CsPbCl3 (Mn∶CsPbCl3)钙钛矿量子点的发光性质。Mn/Pb的量比增加引起的Mn2+发光峰的红移, 被认为是来源于高浓度Mn2+掺杂下的Mn2+-Mn2+对。进一步研究了Mn∶CsPbCl3量子点的发光效率与Mn/Pb的量比之间的关系, 发现随着量比达到5∶1时, 其发光效率明显下降。这种发光效率下降是由于Mn掺杂浓度引起的发光猝灭。Mn∶CsPbCl3量子点的变温发光光谱证实, 随着温度的升高, Mn离子发光峰蓝移, 线宽加宽, 但其发光强度明显增加。

Photoluminescence(PL) properties of Mn doped CsPbCl3 (Mn∶CsPbCl3) perovskite quantum dots(QDs) with various Mn/Pb molar ratios were studied. Two emission bands peaked at around 400 nm and 600 nm, respectively, were observed in Mn∶CsPbCl3 QDs at room temperature. The PL intensity of Mn ion emission in the Mn∶CsPbCl3 QDs was significantly enhanced with respect to the band edge exciton emission as Mn/Pb molar ratio increased from 0.5∶1 to 5∶1. Both the exciton absorption and emission bands in the doped QDs shifted to the blue, which was consistent with the reduction of the QD size. The red shift of Mn2+ emission band with increasing the molar ratio was considered to result from the formation of Mn2+-Mn2+ pairs in the doped QDs due to high concentration Mn doping. Further, the PL quantum efficiency of Mn∶CsPbCl3 QDs as a function of Mn/Pb molar ratio was studied in detail. It is found that the PL quantum yield of Mn2+ gradually increases with the increasing of Mn/Pb molar ratio. The maximum PL quantum yield reaches 62% as Mn/Pb molar ratio is 2∶1. The PL quantum yield drops continually with the increasing of Mn/Pb molar ratio to 5∶1. The reduction of PL quantum yield at high concentration Mn doping is related to Mn doping concentration-induced PL quenching due to the formation of Mn2+-Mn2+ pairs. The temperature-dependence of PL spectra in Mn∶CsPbCl3 QDs demonstrates that Mn2+ emission band shifts to the blue and the emission width is broadened, while PL intensity increases, which is in contrast to Ⅱ-Ⅵ semiconductor QDs.