Tunable n-type and p-type Doping in MoS₂ by Co-Sputtering for Electronic Applications

Two-dimensional (2D) semiconductors offer a promising platform for developing advanced electronics, but controllable doping in 2D semiconductors, especially in selected areas, remains a major technological bottleneck. Here we demonstrate a controllable doping in selected areas of MoS₂ by co-sputtering 2D materials and dopant on single-crystal MoS₂ templates followed by post-growth sulfurization. We co-sputtered rhenium (Re) or vanadium (V) with MoS₂ onto a single-crystal MoS₂ film for the n-type and p-type selected-area doping, respectively. Post-growth annealing in H₂S was performed for healing the crystallinity after the co-sputtering. By controlling the sputtering parameters of dopants and MoS₂, tunable n-type and p-type doping concentrations were achieved. Evidences of the Re- or V-doped MoS₂ film have been characterized by Raman spectroscopy, photoluminescence spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, and scanning transmission electron microscopy. We successfully achieved degenerate n- and p-type doping in MoS₂. Field-effect transistors based on doped contact regions and undoped channel show improved device characteristics with reduced contact resistance. This work provides a promising approach for selected-area doping in 2D semiconductors for future electronic applications.