High-Performance Contact-Doped WSe₂ Transistors Using TaSe₂ Electrodes

Abstract

Two-dimensional (2D) transitional metal dichalcogenides (TMDs) have garnered significant attention due to their potential for next-generation electronics, which require device scaling. However, the performance of TMD-based field-effect transistors (FETs) is greatly limited by the contact resistance. This study develops an effective strategy to optimize the contact resistance of WSe₂ FETs by combining contact doping and 2D metallic electrode materials. The contact regions were doped using a laser, and the metallic TaSe₂ flakes were stacked on doped WSe₂ as electrodes. Doping the contact areas decreases the depletion width, while introducing the TaSe₂ contact results in a lower Schottky barrier. This method significantly improves the electrical performance of the WSe₂ FETs. The doped WSe₂/TaSe₂ contact exhibits an ultralow Schottky barrier height of 65 meV and a contact resistance of 11 kΩ·μm, which is a 50-fold reduction compared to the conventional Cr/Au contact. Our method offers a way on fabricating high-performance 2D FETs.