Phonon thermal transport in ferroelectric α-In2Se3 via first-principles calculations

Haoyue Qi; Chao Wu; Ping Lu; Chenhan Liu

doi:10.1088/1361-6528/ad0c75

Phonon thermal transport in ferroelectric α-In2Se3 via first-principles calculations

Nanotechnology. 2023 Dec 4;35(8). doi: 10.1088/1361-6528/ad0c75.

Authors

Haoyue Qi¹, Chao Wu², Ping Lu¹, Chenhan Liu¹

Affiliations

¹ Micro- and Nano-scale Thermal Measurement and Thermal Management Laboratory, Jiangsu Key Laboratory for Numerical Simulation of Large-Scale Complex Systems, School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, 210023, People's Republic of China.
² Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, 211100, People's Republic of China.

PMID: 37963408
DOI: 10.1088/1361-6528/ad0c75

Abstract

Two-dimensional (2D) ferroelectrics are promising candidates in the field of microelectronics due to their unique properties such as excellent photoelectric responsiveness. However, the thermal properties of 2D ferroelectrics are less investigated. Here, the thickness dependent thermal conductivity in ferroelectricα-In₂Se₃is systematically investigated by the first-principles method combined with the phonon Boltzmann transport equation. On this basis, the strain and oxidation effects on the thermal conductivity of monolayerα-In₂Se₃is further studied. The calculation results show that the thermal conductivity has a significant reduction with decreasing film thickness or increasing tensile strain, and the anharmonic phonon-phonon scattering rate is the intrinsic mechanism for the reduction in thermal conductivity. On the other hand, the replacement of Se atoms by O atoms can achieve a bidirectional and wide-range (12×) tuning of thermal conductivity. The increase in specific heat and phonon group velocity is responsible for the thermal conductivity enhancement at high doping levels while that in phonon-phonon scattering rate is responsible for the thermal conductivity reduction at low doping levels. In all cases, acoustic phonons dominate the in-plane thermal transport behavior. These findings broaden our understanding of phonon transport and its control in ferroelectric semiconductorα-In₂Se₃.

Keywords: ferroelectric; oxidization; tensile strain; thermal conductivity; thickness.