非谐性
声子
化学
钙钛矿(结构)
分子动力学
热导率
化学物理
从头算
卤化物
从头算量子化学方法
计算化学
分子物理学
凝聚态物理
热力学
无机化学
结晶学
分子
物理
有机化学
作者
Tomoyuki Hata,Giacomo Giorgi,Koichi Yamashita
出处
期刊:Nano Letters
[American Chemical Society]
日期:2016-03-24
卷期号:16 (4): 2749-2753
被引量:99
标识
DOI:10.1021/acs.nanolett.6b00457
摘要
Methylammonium lead iodide perovskite (CH3NH3PbI3), the most investigated hybrid organic–inorganic halide perovskite, is characterized by a quite low thermal conductivity. The rotational motion of methylammonium cations is considered responsible for phonon transport suppression; however, to date, the specific mechanism of the process has not been clarified. In this study, we elucidate the role of rotations in thermal properties based on molecular dynamics simulations. To do it, we developed an empirical potential for CH3NH3PbI3 by fitting to ab initio calculations and evaluated its thermal conductivity by means of nonequilibrium molecular dynamics. Results are compared with model systems that include different embedded cations, and this comparison shows a dominant suppression effect provided by rotational motions. We also checked the temperature dependence of the vibrational density of states and specified the energy range in which anharmonic couplings occur. By means of phonon dispersion analysis, we were able to fully elucidate the suppression mechanism: the rotations are coupled with translational motions of cations, via which inorganic lattice vibrations are coupled and scatter each other.
科研通智能强力驱动
Strongly Powered by AbleSci AI