Theoretical Study on the Regulation of Schottky Barrier and Electronic Structure in MoS2/X (X = Sb, As, P, Te) Heterojunctions by Crystal Plane Orientation.

Tuning crystallographic orientation is a crucial strategy for optimizing metal-semiconductor contacts and reducing the Schottky barrier height (SBH) to achieve low contact resistance. Based on density functional theory calculations, this study systematically investigates van der Waals heterostructures composed of MoS2 and low-index crystallographic planes (0001, 011̅2, and 101̅0) of VA-group (Sb, As, and P) and VIA-group (α/β-Te) elements. Among the 15 constructed configurations, 11 exhibit structural stability. The results demonstrate that the crystallographic orientation and elemental species jointly regulate the electronic properties of heterostructures: MoS2/Sb (0001) forms an n-type Ohmic contact (Φn = -0.12 eV) due to strong p-d orbital hybridization; Sb (101̅0)/MoS2 and MoS2/Sb (011̅2) exhibit n-type Schottky contact owing to weakened hybridization. In MoS2/As and MoS2/P systems, the SBH varies with crystallographic planes, primarily attributed to indirect mechanisms such as work function differences and interfacial charge transfer. Meanwhile, MoS2/Te heterostructures undergo a transition from metallic to semiconducting behavior depending on the crystal phase and facet orientation. This work elucidates the mechanism by which crystallographic orientation modulates interfacial charge transfer and orbital hybridization through dangling bond density and work function, enabling precise design from tunable Schottky barriers to ohmic contacts, thereby providing theoretical guidance for the development of two-dimensional semiconductor devices.