Enhancing the contact performance of transition metal dichalcogenide-based field effect transistors using UV-induced doping

A persistent challenge in transition metal dichalcogenide (TMD)-based transistors is the formation of a Schottky Barrier (SB) at the metal–TMD interface which introduces substantial contact resistance and degrades device performance. Minimizing the barrier height and hence contact resistance—ideally to near-zero—is essential for realizing high-performance two dimensional (2D) material-based field-effect transistors. Here, we present a non-invasive photodoping strategy that leverages ultraviolet irradiation to induce localized n-type doping near the contact region, in hBN/TMD field-effect transistors. This targeted doping with UV exposure significantly reduces the SB, leading to a remarkable improvement in device performance. We demonstrate this with hBN/MoS2 transistors, where we achieve a barrier height reduction of ∼100 meV, resulting in a seventy-fold increase in on-state current and a twenty-fold increase in mobility. We further demonstrate the generality of this approach by applying it to other TMD transistors, such as hBN/MoSe2 and hBN/WSe2 hybrids, all of which exhibit similar performance enhancements. These results outline a portable, broadly applicable, and scalable contact engineering strategy for next-generation 2D electronic devices.