Enhanced Tunneling and Ohmic Contacts in MXene/TeO ₂ Heterostructures by Interfacial Engineering

Two-dimensional (2D) van der Waals contacts between metals and semiconductors offer a promising route to mitigate Fermi-level pinning (FLP) and metal-induced gap states (MIGS) in field-effect transistors (FETs). However, the Schottky barrier and tunneling barrier seriously degrade device performance, limited by the work functions and surface properties of 2D layered metals. Herein, we propose an interfacial engineering strategy to modulate the contact properties of MXene/TeO2 heterostructures by tailoring surface terminations (–O, –F, −OH) of MXene electrodes via first-principles calculations. We demonstrate that OH-terminated MXenes form strong hydrogen bonds with TeO2, effectively narrowing the van der Waals gap and enhancing the electron tunneling probability. Notably, OH-terminated MXenes achieve n-type Ohmic contacts at both vertical and lateral interfaces. This work provides a feasible approach for designing high-performance 2D electronic devices with optimized interfacial properties.