Tunable electronic characteristics and Schottky barrier of Si₂P₃/MoSSe van der Waals heterostructures by electric field and strain modulation

In this work, we systematically investigate the interfacial contact characteristics of MoSSe/Si₂P₃ van der Waals heterostructures using first-principles calculations. Among various feasible stacking modes, the AA1-stacking configuration possesses the lowest total energy and excellent thermodynamic stability, serving as the optimal structural model. The interfacial Schottky barrier height and contact performance of the heterostructure can be efficiently tuned via interlayer spacing adjustment, external electric field application, and biaxial strain engineering. At the equilibrium state, the MoSSe/Si₂P₃ heterostructure exhibits intrinsic p-type Schottky contact behavior. Remarkably, reversible and controllable contact transitions from p-type Schottky to n-type Schottky contact, and further to barrier-free Ohmic contact, can be realized through the above three modulation strategies. In particular, the transition from Schottky to Ohmic contact occurs under specific critical modulation conditions, including interlayer compression below 1.8 Å, tensile strain larger than +8%, and negative electric field strength exceeding -0.9 V/Å. The synergistic effect of tunable interfacial contact properties and strain-induced metallicity enables the MoSSe/Si₂P₃ heterostructure to hold prominent application prospects for advanced next-generation nanoelectronic devices.