MoSe2 and MoTe2 primarily based heterostructures, owing to their outstanding photoresponsivity and tunable electrical traits, have emerged as promising candidates for field-effect transistors (FETs) and near-infrared (NIR) optoelectronic purposes. Nevertheless, the contributions of various interfacial processes impose limitations on the band tunability and service dynamics of the heterostructure, posing challenges of their system engineering. On this work, we current the scalable, layer-by-layer development of a trilayer MoSe2/MoTe2 heterostructure over a SiO2 substrate through molecular beam epitaxy (MBE). By leveraging the tunable probing depth of AR-XPS, we efficiently resolve the interfacial bonding modifications, akin to Te migration throughout the interface and localized Mo–Se–Te bonding. Our investigations present that these site-specific processes on the interface induce uneven power stage shifts, Fermi stage pinning, and modulation of the valence band edge. Consequently, deviations from predicted band alignment are noticed, with the Fermi stage pinned round 0.58 eV above the valence band edge on the MoTe2 facet and the anomalous upshift of the valence band most of MoSe2 within the heterostructure. These interfacial results additionally end in a decreased barrier for gap injection, which may enhance bidirectional service transport and gate-tunable gap conduction in such heterostructure-based gadgets. The findings spotlight the essential function of interfacial interactions in governing band alignment of the ultrathin transition steel dichalcogenide (TMDC) heterostructures, offering key insights for advancing nanoelectronic and optoelectronic gadgets via heterostructure band engineering.
