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 MoS₂ via chemical vapor deposition (CVD) using selenium disulfide (SeS₂) as a chalcogen source. Interestingly, doping with 5.5% Se (MoS_1.89Se_0.11) enhanced the electron mobility compared to conventional MoS₂, 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 SeS₂. This approach offers a pathway for tailoring the properties of TMDCs for advanced applications.