Interfacial cost transfer-mediated Fermi stage pinning in MBE-grown 2D 2H-MoSe2/2H-MoTe2 heterostructures


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 provider dynamics of the heterostructure, posing challenges of their gadget engineering. On this work, we current the scalable, layer-by-layer development of a trilayer MoSe2/MoTe2 heterostructure over a SiO2 substrate by way of molecular beam epitaxy (MBE). By leveraging the tunable probing depth of AR-XPS, we efficiently resolve the interfacial bonding modifications, similar 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 vitality 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 aspect and the anomalous upshift of the valence band most of MoSe2 within the heterostructure. These interfacial results additionally lead to a decreased barrier for gap injection, which might enhance bidirectional provider transport and gate-tunable gap conduction in such heterostructure-based gadgets. The findings spotlight the important 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 by means of heterostructure band engineering.
Graphical abstract: Interfacial charge transfer-mediated Fermi level pinning in MBE-grown 2D 2H-MoSe2/2H-MoTe2 heterostructures