Lightly Se-Doped Monolayer MoS₂ Grown by Chemical Vapor Deposition Using SeS₂ Precursor

Transition metal dichalcogenide (TMDC)-based two-dimensional semiconductors are promising materials for next-generation electronic devices. However, challenges such as optimizing the carrier mobility, on/off current ratio, threshold voltage, and minimization of hysteresis remain. Herein, we report lightly Se-doped monolayer MoS 2 via chemical vapor deposition (CVD) using selenium disulfide (SeS 2 ) as a chalcogen source. Interestingly, doping with 5.5% Se (MoS 1.89 Se 0.11 ) enhanced the electron mobility compared to conventional MoS 2, contrary to the typical trend of increased effective mass with substitutional doping. Additionally, bandgap tunability was achieved by controlling the Se content via temperature control of SeS 2 . This approach offers a pathway for tailoring the properties of TMDCs for advanced applications.