Exceptional Thermoelectric Properties of Bilayer GeSe: First Principles Calculation

Materials

Weibin Zhang¹  Haiyin Qing²  Jianhui Yang³  Qiang Fan⁴ 

[1] Institute of Physics and Electronic Information, Yunnan Normal University, Kunming 650500, China;School of Electronic Information and Artificial Intelligence, Leshan Normal University, Leshan 614004, China;School of Mathematics and Physics, Leshan Normal University, Leshan 614004, China;School of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614004, China;

关键词: heterostructure;    electronic structure;    thermoelectric properties;    GeSe;    SnSe;   

DOI  :  10.3390/ma15030971

来源: DOAJ

【 摘 要 】

The geometry structures, vibrational, electronic, and thermoelectric properties of bilayer GeSe, bilayer SnSe, and van der Waals (vdW) heterostructure GeSe/SnSe are investigated by combining the first-principles calculations and semiclassical Boltzmann transport theory. The dynamical stability of the considered structures are discussed with phonon dispersion. The phonon spectra indicate that the bilayer SnSe is a dynamically unstable structure, while the bilayer GeSe and vdW heterostructure GeSe/SnSe are stable. Then, the electronic structures for the bilayer GeSe and vdW heterostructure GeSe/SnSe are calculated with HSE06 functional. The results of electronic structures show that the bilayer GeSe and vdW heterostructure GeSe/SnSe are indirect band gap semiconductors with band gaps of 1.23 eV and 1.07 eV, respectively. The thermoelectric properties, including electrical conductivity, thermal conductivity, Seebeck coefficient, power factor, and figure of merit (ZT) are calculated with semiclassical Boltzmann transport equations (BTE). The results show that the n-type bilayer GeSe is a promising thermoelectric material.

【 授权许可】

Unknown