Open AccessThermoelectric performances for both p- and n-type GeSe
Author(s) -
Qiang Fan,
Jianhui Yang,
Jianwu Cao,
Chunhai Liu
Publication year - 2021
Publication title -
royal society open science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 51
ISSN - 2054-5703
DOI - 10.1098/rsos.201980
Subject(s) - thermoelectric effect , materials science , condensed matter physics , fermi level , electrical resistivity and conductivity , thermoelectric materials , semiconductor , boltzmann constant , band gap , electronic band structure , electron , thermal conduction , density of states , electronic structure , thermal conductivity , optoelectronics , thermodynamics , physics , quantum mechanics , composite material
In this paper, the thermoelectric properties of p-type and n-type GeSe are studied systematically by using first principles and Boltzmann transport theory. The calculation includes electronic structure, electron relaxation time, lattice thermal conductivity and thermoelectric transport properties. The results show that GeSe is an indirect band gap semiconductor with band gap 1.34 eV. Though p-type GeSe has a high density of states near Fermi level, the electronic conductivity is relative low because there is no carrier transport pathway along the a -axis direction. For n-type GeSe, a charge density channel is formed near conduction band minimum, which improves the electrical conductivity of n-type GeSe along the a -axis direction. At 700 K, the optimal ZT value reaches 2.5 at 4 × 10 19 cm −3 for n-type GeSe, while that is 0.6 at 1 × 10 20 cm −3 for p-type GeSe. The results show n-type GeSe has better thermoelectric properties than p-type GeSe, indicating that n-type GeSe is a promising thermoelectric material in middle temperature.