Lim Ae Ran
Department of Carbon Convergence Engineering, Department of Science Education, Jeonju University Jeonju 55069 Korea
Analytical Laboratory of Advanced Ferroelectric Crystals, Jeonju University Jeonju 55069 Korea.
RSC Adv. 2021 May 13;11(29):17622-17629. doi: 10.1039/d1ra02045e.
Hybrid perovskites have potential applications in several electrochemical devices such as supercapacitors, batteries, and fuel cells. Therefore, we studied the thermal behavior and structural dynamics of organic-inorganic hybrid perovskite [(NH)(CH)(NH)]CdBr crystals near phase transition temperatures, (=328 K) and (=363 K), which are correlated to the structural dynamics of cations and anions. The structural geometry and molecular dynamics with emphasis on the role of the [(NH)(CH)(NH)] cation and CdBr anion were discussed in terms of MAS H NMR, MAS C NMR, N NMR, and Cd NMR as a function of the temperature. The environments surrounding H, C, N, and Cd are investigated near and using these results. Spin-lattice relaxation times were discussed in terms of the change in temperature. The discontinuous changes of H and C near are consistent with the change of the lattice constant. Shorter values at high temperature indicate that H and C in the organic chains are more flexible at these temperatures. Based on these results, the physicochemical properties of the cation and anion during the III-II-I phase transitions were discussed. This study was conducted to improve the relatively weak thermal stability compared to the high efficiency for a variety of applications.
杂化钙钛矿在超级电容器、电池和燃料电池等多种电化学器件中具有潜在应用。因此，我们研究了有机-无机杂化钙钛矿[(NH)(CH)(NH)]CdBr晶体在接近相变温度（=328 K）和（=363 K）时的热行为和结构动力学，这与阳离子和阴离子的结构动力学相关。根据变温条件下的MAS H NMR、MAS C NMR、N NMR和Cd NMR，讨论了[(NH)(CH)(NH)]阳离子和CdBr阴离子作用下的结构几何和分子动力学。利用这些结果研究了接近和时H、C、N和Cd周围的环境。根据温度变化讨论了自旋晶格弛豫时间。接近时H和C的不连续变化与晶格常数的变化一致。高温下较短的 值表明有机链中的H和C在这些温度下更灵活。基于这些结果，讨论了III-II-I相变过程中阳离子和阴离子的物理化学性质。本研究旨在改善与多种应用中的高效率相比相对较弱的热稳定性。
