Abstract: The manipulation of dipole moments in Janus transition metal dichalcogenide van der Waals heterojunctions is a cutting-edge research topic in condensed matter physics. This study develops an atomic-scale theoretical model to investigate the bandgap modulation in Janus MoSSe/MoS2 heterojunctions under external electric fields and dipole moments, revealing the underlying physical mechanisms. Our work not only advances the fundamental understanding of the interplay between electric fields and dipoles, but also serves as an instructive case study, enhancing students theoretical and applied knowledge of dipole models in multidisciplinary contexts.

Key words: two-dimensional semiconductor, dipole moment, external electric field, band alignment