Enhanced Charge Carrier Transport in WSe ₂ Field‐Effect Transistors via Monolayer MoS ₂ Tunneling Contacts

ABSTRACT High contact resistance at the metal‐semiconductor interface remains a critical bottleneck in achieving high‐performance field‐effect transistors based on 2D transition metal dichalcogenides, particularly ambipolar tungsten diselenide (WSe ₂ ). Here, we demonstrate a novel tunneling contact architecture using monolayer molybdenum disulfide (MoS ₂ ) inserted between Cr electrodes and few‐layer WSe ₂ channels. The MoS ₂ /WSe ₂ tunneling contact device exhibits significantly improved charge injection characteristics compared to conventional surface contacts, as revealed by output characteristics, Schottky barrier height (SBH) analysis, and transport measurements across temperature. The MoS ₂ tunneling contact configuration reduces SBH to 43.34 meV for holes and 1.2 meV for electrons, enabling efficient direct tunneling in the p‐type and n‐type regimes, respectively. These enhancements are attributed to dipole formation at the interface and suppression of deep‐state pinning. Field‐effect mobility measurements show over 50 times improvement in the p‐type regime and 3 times in the n‐type regime, while achieving more than two orders of magnitude reduction in contact resistance. This work establishes MoS ₂ ‐tunneled heterostructure contacts as a scalable and effective strategy for realizing ambipolar, low‐resistance, and high‐mobility 2D electronics.