P-type Doping in Large-Area Monolayer MoS₂ by Chemical Vapor Deposition

Molybdenum disulfide (MoS₂) with excellent properties has been widely reported in recent years. However, it is a great challenge to achieve p-type conductivity in MoS₂ because of its native stubborn n-type conductivity. Substitutional transition metal doping has been proved to be an effective approach to tune their intrinsic properties and enhance device performance. Herein, we report the growth of Nb-doping large-area monolayer MoS₂ by a one-step salt-assisted chemical vapor deposition method. Electrical measurements indicate that Nb doping suppresses n-type conductivity in MoS₂ and shows an ambipolar transport behavior after annealing under the sulfur atmosphere, which highlights the p-type doping effect via Nb, corresponding to the density functional theory calculations with Fermi-level shifting to valence band maximum. This work provides a promising approach of two-dimensional materials in electronic and optoelectronic applications.