Investigation of the bipolar effect in the thermoelectric material CaMg2Bi2 using a first-principles study

被引：120

作者：

Gong, J. J. ^{[1
]}

Hong, A. J. ^{[1
]}

Shuai, J. ^{[2
,3
]}

Li, L. ^{[1
]}

Yan, Z. B. ^{[1
]}

Ren, Z. F. ^{[2
,3
]}

Liu, J. -M. ^{[1
]}

机构：

[1] Nanjing Univ, Lab Solid State Microstruct & Innovat, Ctr Adv Microstruct, Nanjing 210093, Jiangsu, Peoples R China

[2] Univ Houston, Dept Phys, Houston, TX 77204 USA

[3] Univ Houston, TcSUH, Houston, TX 77204 USA

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2016年 / 18卷 / 24期

关键词：

ELECTRONIC-STRUCTURE; PERFORMANCE; SCATTERING; EFFICIENCY; PROPERTY;

D O I：

10.1039/c6cp02057g

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The bipolar effect in relatively narrow band-gap thermoelectric (TE) compounds is a negative process deteriorating the TE properties particularly at higher temperatures. In this work, we investigate the TE performance of the compound CaMg2Bi2 using the first-principles calculation and semi-classical Boltzmann transport theory in combination with our experimental data. It is revealed that this compound exhibits a remarkable bipolar effect and temperature-dependent carrier concentration. The bipolar effect imposes remarkable influence on all the electron-transport related TE parameters. An effective carrier concentration n(eff) as a function of temperature is proposed to account for the bipolar effect induced carrier excitations. The as-evaluated TE parameters then show good consistency with measured results. This work may shed light on our understanding of the bipolar effect in TE compounds.

引用

页码：16566 / 16574

页数：9

共 46 条

[1] Thermoelectric Efficiency of Single-Molecule Junctions: Phase Diagram Constructed from First-Principles Calculations [J].