Electronic Properties of Janus TMD WSSe/WX₂ (X = S, Se) Heterostructure by External Strain: A Hybrid Functional Study

Harvesting solar energy for artificial photosynthesis is an emerging field in alternative energy research. In this work, the structural, electronic, and optical properties of WX2 (X = S, Se)/WSSe heterostructures were systematically studied. Based on the computation results, these heterostructures outperform the isolated WSSe or WX2 monolayers in terms of photocatalytic performance. A type-II band alignment is present in both of the investigated heterostructures, which encourages the spatial separation of photogenerated carriers and raises the total photocatalytic efficiency. Remarkably, band gap alterations in the 0.2–2.0 eV range can be promoted by applying strain-engineering modulation, which allows for well-tuned electrical features. Through methodical research, the tunable bandgap and integrated electric field produced by the dipole moment under strain of the WSSe/WX2 (X = S, Se) heterostructure with various stacking configurations can be utilized as exceptional photocatalysts for water splitting even in the presence of infrared light. Our calculation results reveal that 2D WSSe/WX2 is a promising candidate for electronics, optoelectronics, and photocatalytic water-splitting applications.