Asymmetrical Transport Distribution Function: Skewness as a Key to Enhance Thermoelectric Performance  

作　　者：Jin-Cheng Zhen 

机构地区：[1]Department of Physics,Xiamen University,Xiamen 361005,China [2]Department of Physics and Department of New Energy Science and Engineering,Xiamen University Malaysia,Sepang 43900,Malaysia

出　　处：《Research》2022年第4期397-410,共14页研究（英文）

基　　金：This research was supported by Xiamen University Malaysia Research Fund(No.XMUMRF/2019-C3/IORI/0001).

摘　　要：How to achieve high thermoelectric figure of merit is still a scientific challenge.By solving the Boltzmann transport equation,thermoelectric properties can be written as integrals of a single function,the transport distribution function(TDF).In this work,the shape effects of transport distribution function in various typical functional forms on thermoelectric properties of materials are systematically investigated.It is found that the asymmetry of TDE,characterized by skewness,can be used to describe universally the trend of thermoelectric properties.By defining symmetric and asymmetric TDF functions,a novel skewness is then constructed for thermoelectric applications.It is demonstrated,by comparison with ab initio calculations and experiments,that the proposed thermoelectric skewness not only perfectly captures the main feature of conventional skewness but also is able to predict the thermoelectric power accurately.This comparison confirms the unique feature of our proposed thermoelectric skewness,as well as its special role of connection between the statistics of TDF and thermoelectric properties of materials.It is also found that the thermoelectric performance can be enhanced by increasing the asymmetry of TDF.Finally,it is also interesting to find that the thermoelectric transport properties based on typical quantum statistics(Fermi-Dirac distributions)can be well described by typical shape parameter(skewness)for classical statistics.

关 键 词：properties materials FERMI 

分 类 号：O17[理学—数学]