Tong Zhen, Dumitrică Traian, Frauenheim Thomas
Shenzhen JL Computational Science and Applied Research Institute, Shenzhen 518131, China.
Department of Mechanical Engineering, University of Minnesota, Minnesota 55455, United States.
Nano Lett. 2021 May 26;21(10):4351-4356. doi: 10.1021/acs.nanolett.1c00935. Epub 2021 May 12.
Monolayer molybdenum trioxide (MoO) is an emerging two-dimensional (2D) material with high electrical conductivity but unexplored thermal conductivity. Using first-principles calculations and a Boltzmann transport theoretical framework, we predict a record low room-temperature phonon thermal conductivity (κ) of 1.57 and 1.26 W/mK along the principal in-plane directions of the MoO monolayer. The behavior is attributed to the combination of soft flexural and in-plane acoustic modes, which are coupled through the finite layer thickness, and to the strong bonding anharmonicity, which gives rise to significant 3- and 4-phonon scattering. These insights suggest new indicators for guiding the search of 2D materials with low κ and motivates κ measurements in MoO and its applications as a thermoelectric and thermally protective material.
单层三氧化钼（MoO）是一种新兴的二维材料，具有高电导率，但热导率尚未得到研究。通过第一性原理计算和玻尔兹曼输运理论框架，我们预测MoO单层沿主要面内方向的室温声子热导率（κ）创纪录地低，分别为1.57和1.26 W/mK。这种行为归因于通过有限层厚度耦合的软弯曲和面内声学模式的组合，以及导致显著的三声子和四声子散射的强键非谐性。这些见解为寻找低κ二维材料提供了新的指标，并推动了对MoO热导率的测量及其作为热电和热防护材料的应用。
