Clathrate structure of YB_(3)C_(3) for high-performance thermoelectrics with superior mechanical properties  

作　　者：Yangfan Cui Shuai Duan Xiaojun Wang Qinghang Tang Jinyang Xi Xiaobing Liu Yongsheng Zhang Xin Chen 

机构地区：[1]Laboratory of High Pressure Physics and Material Science(HPPMS),School of Physics and Physical Engineering,Qufu Normal University,Qufu,Shandong,273165,China [2]Materials Genome Institute,Shanghai University,Shanghai,200444,China [3]Advanced Research Institute of Multidisciplinary Science,Qufu Normal University,Qufu,Shandong,273165,China

出　　处：《Journal of Materiomics》2024年第4期783-791,共9页无机材料学学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(11974208,52172212);Shandong Provincial Science Foundation(ZR2020YQ05,ZR2021YQ03,ZR2023JQ001);The authors acknowledge financial support from the program of“Young Scientists of Taishan Scholar”(No.tsqn202211128,tsqn202306184);“Distinguished Expert of Taishan Scholar”(No.tstp20221124).

摘　　要：Exploring high-performance thermoelectric materials with improved mechanical properties is important for broadening the application scope and the assembly requirement of stable devices.This work presents an effective strategy to discover hard thermoelectric material by inserting foreign atoms in the rigid covalent framework.We demonstrate this in boron-carbon clathrate VII structure,showing a promising candidate for highly efficient thermoelectric energy conversion,especially with Y atom filled in the cage,with a peak zT of 0.73 at 1,000 K.The ab initio calculations indicate that YB_(3)C_(3) system has low lattice thermal conductivity of 4.5 W/(m·K)at 1,000 K due to the strong rattling of encaged Y atom.The strongly covalent framework provides highly degenerate band structures consisting of heavy and light electron pockets,which can maintain high carrier mobility arising from small effective mass and thus large group velocity.Consequently,high power factor can be achieved in YB_(3)C_(3) for both electron and hole doping.In addition,it exhibits well mechanical properties and a Vickers hardness of 23.7 GPa because of the strong covalent boron-carbon framework.This work provides a novel avenue for the search of high-performance thermoelectric materials with excellent mechanical properties,based on boron-carbon clathrate structure.

关 键 词：Clathrate structure Thermoelectric performance First-principles calculations Mechanical properties Thermal conductivity 

分 类 号：TB34[一般工业技术—材料科学与工程]