Strain and Electric Field Engineering of G-ZnO/SnXY (X, Y = S, Se) S-Scheme Heterostructures for Photocatalyst and Electronic Device Applications: A Hybrid DFT Calculation

Yue Tang; YiPeng Wang; Xinlu Cheng; Hong Zhang

doi:10.1021/acsami.4c03666

Strain and Electric Field Engineering of G-ZnO/SnXY (X, Y = S, Se) S-Scheme Heterostructures for Photocatalyst and Electronic Device Applications: A Hybrid DFT Calculation

ACS Appl Mater Interfaces. 2024 May 29;16(21):27381-27393. doi: 10.1021/acsami.4c03666. Epub 2024 May 16.

Authors

Yue Tang¹, YiPeng Wang², Xinlu Cheng¹, Hong Zhang³

Affiliations

¹ Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
² College of Applied Technology, Shenzhen University, Shenzhen 518061, China.
³ College of Physics, Sichuan University, Chengdu 610064, China.

PMID: 38752270
DOI: 10.1021/acsami.4c03666

Abstract

Using hybrid density functional theory calculations, we systematically study the biaxial strain and electric field modulated electronic properties of g-ZnO/SnS₂, g-ZnO/SnSe₂, and g-ZnO/SnSSe S-scheme van der Waals heterostructures (vdWHs). g-ZnO/SnS₂ and g-ZnO/SnSSe are found to be promising photocatalysts for water splitting with high solar-to-hydrogen efficiencies, even under acidic, alkaline, and high-stress conditions. The strain effect on the bandgaps of g-ZnO/SnXY is explained in detail according to the correlation between geometry structure and orbital hybridization of SnXY, which could help understand the strain-induced band structure evolutions in other SnXY (X, Y = S, Se)-based vdWHs. It is surprising that under an external electric field, g-ZnO/SnS₂, g-ZnO/SnSe₂, and g-ZnO/SnSSe can offer the occupied nearly free-electron (NFE) states. In many materials, NFE states are usually unoccupied and is not conducive to the charge transport. The NFE state in g-ZnO/SnSe₂ is the most sensitive to the electric field and might be promising electron transport channel in nanoelectronic devices. g-ZnO/SnSe₂ might also have application potential in gas sensors and high-temperature superconductors.

Keywords: S-scheme heterostructure; electric field; hybrid density functional theory; nearly free electron state; photocatalytic water splitting; strain; van der Waals heterostructure.