Mechanical, optical, and thermoelectric properties of semiconducting ZnIn2X4 (X= S, Se, Te) monolayers

authored by

Mohammad Ali Mohebpour, Bohayra Mortazavi, Timon Rabczuk, Xiaoying Zhuang, Alexander V. Shapeev, Meysam Bagheri Tagani

Abstract

In the latest experimental success in the field of two-dimensional materials, ZnIn2S4 nanosheets with a highly appealing efficiency for photocatalytic hydrogen evolution were synthesized [S. Zhang, ACS Nano 15, 15238 (2021)1936-085110.1021/acsnano.1c05834]. Motivated by this accomplishment, herein, we conduct first-principles-based calculations to explore the physical properties of the ZnIn2X4 (X = S, Se, Te) monolayers. The results confirm the desirable dynamical and mechanical stability of the ZnIn2X4 monolayers. ZnIn2S4 and ZnIn2Se4 are semiconductors with direct band gaps of 3.94 and 2.77 eV, respectively while ZnIn2Te4 shows an indirect band gap of 1.84 eV. The optical properties achieved from the solution of the Bethe-Salpeter equation predict the exciton binding energy of the ZnIn2S4, ZnIn2Se4, and ZnIn2Te4 monolayers to be 0.51, 0.41, and 0.34 eV, respectively, suggesting the high stability of the excitonic states against thermal dissociation. Using the iterative solutions of the Boltzmann transport equation accelerated by machine learning interatomic potentials, the room-temperature lattice thermal conductivity of the ZnIn2S4, ZnIn2Se4, and ZnIn2Te4 monolayers is predicted to be remarkably low as 5.8, 2.0, and 0.4 W/mK, respectively. Due to the low lattice thermal conductivity, high thermopower, and large figure of merit, we propose the ZnIn2Se4 and ZnIn2Te4 monolayers as promising candidates for thermoelectric energy conversion systems. This study provides an extensive vision concerning the intrinsic physical properties of the ZnIn2X4 nanosheets and highlights their characteristics for energy conversion and optoelectronics applications.

Organisation(s)

Institute of Photonics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines

External Organisation(s)

Guilan University
Tongji University
Skolkovo Institute of Science and Technology

Type

Article

Journal

Physical Review B

Volume

105

ISSN

2469-9950

Publication date

27.04.2022

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Electronic version(s)

https://doi.org/10.1103/PhysRevB.105.134108 (Access: Closed)