Interfacial Control of Degradation Pathways in 2D Heterostructures

In two‐dimensional (2D) electronic devices, heterointerfaces between dissimilar 2D materials are essential for mechanical support and electrical integration, yet they can alter interfacial electronic structure and reaction kinetics. The long‐term influence of interfacial material pairing on reactivity under ambient exposure remains poorly understood. Here, it is revealed that oxidation of 2H‐MoTe 2 proceeds rapidly through defect‐driven pathways on insulating layers, whereas metallic contacts strongly suppress such degradation during extended ambient exposure. This suppression arises from the rapid delocalization of oxidation‐induced carriers into the metallic layer, as confirmed by first‐principles calculations showing long‐range electronic perturbations, which lowers local reactivity and favors gradual basal‐plane oxidation. To further elucidate the role of oxygen and moisture during ambient aging, controlled exposures to these species are performed, revealing that oxygen primarily drives basal‐plane oxidation while moisture accelerates defect‐site corrosion. The work on heterointerface‐mediated charge redistribution and active species‐induced degradation provides a framework for examining oxidation mechanisms in air‐sensitive 2D materials and for designing passivation strategies to achieve long‐term stable device integration.