Tunable Electronic Properties and Contact Performance of Type‐II HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ Van der Waals Heterostructure

Abstract Recently, the assembly of van der Waals heterostructures (vdWH) has proved to be an effective strategy to alter the properties and enhance the functionality of multifunctional devices based on 2D materials. Herein, first‐principles calculations are employed to construct the / vdWH, exploring its electronic properties, contact characteristics, and the impact of electric gating. The / vdWH is predicted to be structurally, thermally, and mechanically stable. The / vdWH leads to a reduction in the bandgap compared to the constituent components, potentially enhancing optical absorption. Furthermore, the / heterostructure forms the type‐II band alignment, localizing electrons and holes predominantly in the and layers, respectively. Such type‐II / heterostructure makes it promising candidate for the optoelectronic devices, benefiting from the spatial separation of photogenerated electron‐hole pairs. Notably, the electronic properties and contact characteristics of the / vdWH are controllable under electric gating. The negative electric gating facilitates to a transformation from type‐II to type‐I band alignment, while the positive electric field induces a shift from semiconductor to metal in the / vdWH. This findings can provide valuable insights into the fundamental aspects that contribute to the exceptional performance observed in / vdWH toward high‐performance multifunctional devices.