Boundary-scattering induced Seebeck coefficient enhancement in thin films within relaxation time approximation

被引：2

作者：

Viet-Anh Tran ^{[1
]}

Phuong-Anh Tran ^{[1
]}

Hung Q Nguyen ^{[2
]}

Giang H Bach ^{[1
]}

Toan T Nguyen ^{[1
,3
]}

机构：

[1] Vietnam Natl Univ, Univ Sci, Fac Phys, 334 Nguyen Trai St, Hanoi, Vietnam

[2] Vietnam Natl Univ, Univ Sci, Nano & Energy Ctr, 334 Nguyen Trai St, Hanoi, Vietnam

[3] Vietnam Natl Univ, Univ Sci, Key Labs Multiscale Simulat Complex Syst, 334 Nguyen Trai St, Hanoi, Vietnam

来源：

PHYSICA B-CONDENSED MATTER | 2022年 / 635卷

关键词：

Seebeck coefficient; Semiconductor thin film; Boltzmann transport equation; Relaxation time approximation; Boundary scattering; QUANTUM-WELL STRUCTURES; THERMOELECTRIC FIGURE;

D O I：

10.1016/j.physb.2022.413800

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

We investigate the Seebeck coefficient based on the Boltzmann transport equation of electrons within the relaxation time approximation. Using boundary conditions along the film thickness of a thermoelectric material, we observe the enhancement of Seebeck coefficient due to electrons elastically scattering on the boundaries when the film thickness is reduced, which agrees with experimental observations and theoretical predictions. Using this simple approximation, the Seebeck coefficient of thin films increases up to 16% in comparison to the bulk value. The main factor that affects the increase of the Seebeck coefficient comes from the chemical potential which controls carrier concentrations. We also analyze the linear and non-linear temperature dependence of the Seebeck coefficient at various chemical potentials based on an explicit expression for the Seebeck coefficient in the bulk limit.

引用

页数：5