【摘要】 本文利用氘核磁共振（²H NMR）技术对阳离子掺杂铅溴钙钛矿MA_0.6DMA_0.4PbBr₃中内嵌阳离子的运动状态进行了较为深入的研究．通过对二甲基胺（DMA）和甲胺（MA）阳离子的选择性氘代，我们实现了对上述材料中不同内嵌阳离子的选择性NMR观测．研究结果显示，在低温下，该材料中的DMA与MA阳离子都接近于双重旋转模型；随着温度升高，DMA与MA阳离子的运动自由度增加，其运动逐步转变为快速各向同性运动．且在相同温度时，DMA阳离子比MA阳离子运动更快，表明该材料中阳离子运动状态不一致．在对阳离子运动研究的基础上，我们对该材料相结构转变的分子机制进行了探讨．更多还原

【Abstract】 In this paper,²H nuclear magnetic resonance （NMR） was performed to study the motions of the embedded cations in the cation-doped lead bromide perovskite (MA_0.6DMA_0.4PbBr₃).By selectively deuterating dimethylamine （DMA） and methylammonium （MA） cations,we achieved selective NMR observations of the different embedded cations in the materials.The results show that at low temperatures,both the DMA and MA cations in the material have molecular motions close to the double rotation model.As the temperature increases,the motion freedom of the DMA and MA cations increases,and the motions gradually transform into fast isotropic motions.It was observed that the DMA cations have higher mobility than the MA cations in the same materials at the same temperature,indicating that there is a significant inhomogeneity in the states of cations in the material.Based on the study of the cation motions,the molecular mechanism of the phase transition of the material was discussed.更多还原