Optoelectronic and photocatalytic behaviour of a type-II GaAlS2/HfS2heterostructure: ab initio study

Disha Mehta; Yashasvi Naik; Nidhi Modi; P R Parmar; P B Thakor

doi:10.1088/1361-6528/ad43f3

Optoelectronic and photocatalytic behaviour of a type-II GaAlS₂/HfS₂heterostructure: ab initio study

Nanotechnology. 2024 May 17;35(31). doi: 10.1088/1361-6528/ad43f3.

Authors

Disha Mehta¹, Yashasvi Naik¹, Nidhi Modi², P R Parmar¹, P B Thakor¹

Affiliations

¹ Department of Physics, Veer Narmad South Gujarat University, Surat, Gujarat, 395007, India.
² Department of Physics, Sir P. T. Sarvajanik College of Science, Surat, Gujarat, 395001, India.

PMID: 38670075
DOI: 10.1088/1361-6528/ad43f3

Abstract

Theoretical examination based on first principle computation has been conducted for van der Waals heterostructure (vdwHS) GaAlS₂/HfS₂including structural, optoelectronic and photocatalytic characteristics. From the adhesion energy calculation, the AB configuration of GaAlS₂/HfS₂vdwHS is the most stable. A type-II GaAlS₂/HfS₂vdwHS is a dynamically and thermally stable structure. The band edge position, projected band, and projected charge densities verify the type-II alignment of GaAlS₂/HfS₂vdwHS. For GaAlS₂/HfS₂, GaAlS₂is acting as a donor and HfS₂is acting as an acceptor ensured by the charge density difference plot. The electron localized function validates the weak van der Waals interaction between GaAlS₂and HfS₂. The GaAlS₂/HfS₂vdwHS possess an indirect bandgap of 1.54 eV with notable absorption in the visible range. The findings assure that the GaAlS₂/HfS₂vdwHS is an efficient photocatalyst for pH 4-8. The band alignment of GaAlS₂/HfS₂is suitable for Z-scheme charge transfer. The strain influenced band edge suggests that the GaAlS₂/HfS₂vdwHS remains photocatalytic for strain-4%to+6%in both cases of uniaxial and biaxial strains.

Keywords: GaAlS2/HfS2 heterostructure; Z-scheme; optoelectronic behaviour; photocatalytic activity; strain effect; type-II band alignment.