二甲基胺阳离子掺杂甲胺铅溴钙钛矿材料的固体NMR研究

马开阳,乔文成,王雪璐,姚叶锋

A Solid-state NMR Study of Dimethylamine Cation-doped MAPbBr3 Perovskite Materials

MA Kaiyang,QIAO Wencheng,WANG Xuelu,YAO Yefeng

图4 MA在MAPbBr3不同相结构中的运动模型和模拟2H NMR谱[22].(a) MA处于静止状态；(b) MA离子开始进行甲基内旋转运动.拟合条件：C-D键与C-N轴之间的夹角θ = 70?，运动速率达到快极限（fast limit）；(c) MA进行甲基内旋转运动的同时绕Rc轴进行轴向旋转运动.拟合条件：C-N键与Rc轴间的夹角θ = 54.7?，绕Rc轴旋转的速率（Ω）分别为30 kHz和60 kHz；(d) MA离子进行快速的各向同性运动，运动速率达到fast limit

Fig. 4 Motion models of MA and the corresponding simulated 2H spectra in MAPbBr3 with different phase structures[22]. (a) MA in static state and the simulated spectrum; (b) The methyl group of MA under intrinsic rotation along C-N bond and the simulated spectrum. Simulation condition: the angle between C-D bond and C-N axis θ = 70?, and the rotation rate reaches fast limit; (c) MA undergoes intrinsic methyl rotation and meanwhile rotates around Rc axis. Simulation condition: the inclined angle between C-N bond and Rc axis is θ = 54.7?, and the rotation rates (Ω) along the Rc axis are 30 kHz and 60 kHz, respectively; (d) MA undergoes isotropic tumbling and the motion rate reaches fast limit