Electrical Polarity Modulation in V-Doped Monolayer WS₂ for Homogeneous CMOS Inverters

As demand for higher integration density and smaller devices grows, silicon-based complementary metal-oxide-semiconductor (CMOS) devices will soon reach their ultimate limits. 2D transition metal dichalcogenides (TMDs) semiconductors, known for excellent electrical performance and stable atomic structure, are seen as promising materials for future integrated circuits. However, controlled and reliable doping of 2D TMDs, a key step for creating homogeneous CMOS logic components, remains a challenge. In this study, a continuous electrical polarity modulation of monolayer WS₂ from intrinsic n-type to ambipolar, then to p-type, and ultimately to a quasi-metallic state is achieved simply by introducing controllable amounts of vanadium (V) atoms into the WS₂ lattice as p-type dopants during chemical vapor deposition (CVD). The achievement of purely p-type field-effect transistors (FETs) is particularly noteworthy based on the 4.7 at% V-doped monolayer WS₂, demonstrating a remarkable on/off current ratio of 10⁵. Expanding on this triumph, the first initial prototype of ultrathin homogeneous CMOS inverters based on monolayer WS₂ is being constructed. These outcomes validate the feasibility of constructing homogeneous CMOS devices through the atomic doping process of 2D materials, marking a significant milestone for the future development of integrated circuits.