2023/05/16 by Ravina Beniwal, M. Suman Kalyan, Beniwal, Ravina +9
Chemistry · Materials Science · #2D Materials and Applications #FOS: Physical sciences #Inorganic Chemistry and Materials #Machine Learning in Materials Science #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · pdf · doi:10.48550/arxiv.2305.09223
openalex publication_date 2023/05/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We explore the direct to indirect band gap transitions in MX2 (M= Mo/W, X= S/Se) transition metal dichalcogenides heterobilayers for different system compositions, strains, and twist angles based on first principles density functional theory calculations within the G0W0 approximation. The obtained band gaps that typically range between 1.4-2.0 eV are direct/indirect for different/same chalcogen atom systems and can often be induced through expansive/compressive biaxial strains of a few percent. A direct to indirect gap transition is verified for heterobilayers upon application of a finite 16∘ twist that weakens interlayer coupling. The large inter-layer exciton binding energies of the order of ∼~250~meV estimated by solving the Bethe-Salpeter equation suggest these systems are amenable to be studied through infrared and Raman spectroscopy.