Phonon transport properties of Janus Pb_(2)XAs(X=P,Sb,and Bi)monolayers:A DFT study  

作　　者：耿嘉鑫 张培 汤准韵 欧阳滔 Jiaxin Geng;Pei Zhang;Zhunyun Tang;Tao Ouyang(School of Physics and Optoelectronics and Hunan Key Laboratory for Micro-Nano Energy Materials and Device,Xiangtan University,Xiangtan 411105,China;Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials,School of Physics and Electronics,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]School of Physics and Optoelectronics and Hunan Key Laboratory for Micro-Nano Energy Materials and Device,Xiangtan University,Xiangtan 411105,China [2]Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials,School of Physics and Electronics,Hunan University of Science and Technology,Xiangtan 411201,China

出　　处：《Chinese Physics B》2024年第4期71-76,共6页中国物理B（英文版）

基　　金：Project supported by the Youth Science and Technology Talent Project of Hunan Province of China (Grant No.2022RC1197);the National Natural Science Foundation of China (Grant No.52372260)。

摘　　要：Grasping the underlying mechanisms behind the low lattice thermal conductivity of materials is essential for the efficient design and development of high-performance thermoelectric materials and thermal barrier coating materials.In this paper,we present a first-principles calculations of the phonon transport properties of Janus Pb_(2)PAs and Pb_(2)SbAs monolayers.Both materials possess low lattice thermal conductivity,at least two orders of magnitude lower than graphene and h-BN.The room temperature thermal conductivity of Pb_(2)SbAs(0.91 W/m K)is only a quarter of that of Pb_(2)PAs(3.88 W/m K).We analyze in depth the bonding,lattice dynamics,and phonon mode level information of these materials.Ultimately,it is determined that the synergistic effect of low group velocity due to weak bonding and strong phonon anharmonicity is the fundamental cause of the intrinsic low thermal conductivity in these Janus structures.Relative regular residual analysis further indicates that the four-phonon processes are limited in Pb_(2)PAs and Pb_(2)SbAs,and the three-phonon scattering is sufficient to describe their anharmonicity.In this study,the thermal transport properties of Janus Pb_(2)PAs and Pb_(2)SbAs monolayers are illuminated based on fundamental physical mechanisms,and the low lattice thermal conductivity endows them with the potential applications in the field of thermal barriers and thermoelectrics.

关 键 词：lattice thermal conductivity weak bonding phonon anharmonicity first principles calculations 

分 类 号：TB34[一般工业技术—材料科学与工程] O469[理学—凝聚态物理]