Hf_(2)CF_(2)单层热传输及热电性质的第一原理研究  

First-principles study of the thermal transports and thermoelectric properties of MXene Hf_(2)CF_(2) monolayer

作　　者：董文欣 李铁平[1] 张莉 丁迎春 何开华[1] DONG Wen-Xin;LI Tie-Ping;ZHANG Li;DING Ying-Chun;HE Kai-Hua(Faculty of Maths and Physics,China University of Geosciences,Wuhan 430074,China;Department of Material and Chemical Engineering,Yibin University,Yibin 644000,China)

机构地区：[1]中国地质大学(武汉)数学与物理学院,武汉430074 [2]宜宾学院材料与化学工程学部,宜宾644000

出　　处：《原子与分子物理学报》2025年第4期168-176,共9页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(41474067);四川省科技支持计划(2023YFSY0036)。

摘　　要：二维MXene材料是一种新型的功能性材料,其在热电领域具有潜在应用价值.本文采用第一性原理计算方法,通过求解声子和电子的玻尔兹曼输运方程,计算研究了MXene Hf_(2)CF_(2)单层的热传输特征和热电性质.声子谱揭示了Hf_(2)CF_(2)单层具有热力学稳定性.在室温条件下,Hf_(2)CF_(2)单层的晶格热导率为14.25 Wm^(-1)K^(-1),且随着温度的升高而降低;电子热导率却随着温度和掺杂浓度的增加而升高.电输运性质中,电导率和Seebeck系数随载流子浓度的变化相反,确保能够获得优异的热电性能.在600 K条件下,n型MXene Hf_(2)CF_(2)单层的最大功率因子可以达到61.24 mW/(mK^(2)).载流子迁移率具有较高的各向异性,且电子的迁移率远远高于空穴的迁移率.基于热导及电导计算结果,n型MXene Hf_(2)CF_(2)单层沿x轴方向的热电优值可达到1.75,高于其他已报道的类似结构的热电优值,表明了MXene Hf_(2)CF_(2)单层是一种潜在的高性能n型热电材料.As a new functional material,two dimension MXene materials have potential application in the thermoelectric field.In this work,we calculated the thermal transports and thermoelectric properties of the MXene Hf_(2)CF_(2) monolayer by first-principles and solving Boltzmann transport equation for both phonon and electron components.The Hf_(2)CF_(2) monolayer is found to be stable from phonon spectra.At room temperature,the calculated lattice thermal conductivity of Hf_(2)CF_(2) is 14.25 Wm^(-1) K^(-1),and it decreases with the increasing temperature.However,the electronic thermal conductivity increases with increasing temperature and doping concentration.In terms of electrical transport properties,the variations of electrical conductivity and Seebeck coefficient with carrier concentration are completely opposite,allowing the Seebeck coefficient and electrical conductivity to work together to produce excellent thermoelectric performance.Meanwhile,the largest value of power factor can reach 61.24 mW/(mK^(2))for the n-type MXene Hf_(2)CF_(2) monolayer at 600 K.In addition,we also calculated the carrier mobility and found that it exhibits high anisotropy,with electron mobility significantly higher than hole mobility.This suggests that the thermoelectric performance of the material is likely dominated by n-type doping.The n-type MXene Hf_(2)CF_(2) monolayer achieves an optimal figure of merit of 1.75 at 600 K and carrier concentration of 1.80×1013 cm-2.This study indicates that the MXene Hf_(2)CF_(2) monolayer is a potential high-performance n-type thermoelectric material.

关 键 词：MXene Hf_(2)CF_(2) 热电性能 晶格热导率 第一性原理 

分 类 号：O469[理学—凝聚态物理]