摘要
The two-dimensional(2D)material-based thermal switch is attracting attention due to its novel applications,such as energy conversion and thermal management,in nanoscale devices.In this paper,we observed that the reversible 2H–1T′phase transition in MoTe_(2)is associated with about a fourfold/tenfold change in thermal conductivity along the X/Y direction by using first-principles calculations.This phenomenon can be profoundly understood by comparing the Mo–Te bonding strength between the two phases.The 2H-MoTe_(2)has one stronger bonding type,while 1T′-MoTe_(2)has three weaker types of bonds,suggesting bonding inhomogeneity in 1T′-MoTe_(2).Meanwhile,the bonding inhomogeneity can induce more scattering of vibration modes.The weaker bonding indicates a softer structure,resulting in lower phonon group velocity,a shorter phonon relaxation lifetime and larger Gr¨uneisen constants.The impact caused by the 2H to 1T′phase transition in MoTe_(2)hinders the propagation of phonons,thereby reducing thermal conductivity.Our study describes the possibility for the provision of the MoTe_(2)-based controllable and reversible thermal switch device.
作者
张定波
任卫君
王珂
陈帅
张力发
倪宇翔
张刚
Dingbo Zhang;Weijun Ren;Ke Wang;Shuai Chen;Lifa Zhang;Yuxiang Ni;Gang Zhang(School of Physical Science and Technology,Southwest Jiaotong University,Chengdu 610031,China;Institute of High Performance Computing,A*STAR 138632,Singapore;Center for Phononics and Thermal Energy Science,China-EU Joint Laboratory for Nanophononics,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China;School of Automation,Xi’an University of Posts and Telecommunications,Shaanxi 710121,China;NNU-SULI Thermal Energy Research Center,and Center for Quantum Transport and Thermal Energy Science(CQTES),School of Physics and Technology,Nanjing Normal University,Nanjing 210023,China)
基金
the China Scholarship Council(Grant No.202107000030)
RIE2020 Advanced Manufacturing and Engineering(AME)Programmatic(Grant No.A1898b0043)
A*STAR Aerospace Programme(Grant No.M2115a0092)。