Near-Ideal van der Waals NbSe 2 Contacts for WSe 2 CMOS Electronics

Reliable, low-resistance contacts remain a central bottleneck in two-dimensional (2D) semiconductor devices, where Fermi-level pinning (FLP) at metal–semiconductor interfaces limits carrier injection and masks intrinsic transport. Here, we demonstrate that metallic van der Waals (vdW) contacts based on transferred NbSe 2 enable near-ideal p-type operation in WSe 2 field-effect transistors. Devices with NbSe 2 contacts exhibit clear p-type characteristics, ohmic behavior, and high on/off ratios, in contrast to conventional high-work-function metal contacts. Temperature-dependent measurements reveal a reduced Schottky barrier height of ∼0.06 eV, compared to ∼0.26 eV for Pt contacts. Four-point-probe measurements confirm a low contact resistance and channel-dominated transport, evidencing efficient carrier injection across the vdW interface. Furthermore, a dopant-free complementary metal–oxide–semiconductor (CMOS) inverter is realized by integrating p-type NbSe 2 and n-type Sb contacts on WSe 2 . These results establish metallic vdW contacts as an effective strategy to suppress FLP and enable high-performance 2D electronics.