Wafer-Scale Oxygen-Doped MoS₂ Monolayer

Monolayer MoS₂ is an emergent 2D semiconductor for next-generation miniaturized and flexible electronics. Although the high-quality monolayer MoS₂ is already available at wafer scale, doping of it uniformly remains an unsolved problem. Such doping is of great importance in view of not only tailoring its properties but also facilitating many potential large-scale applications. In this work, the uniform oxygen doping of 2 in wafer-scale monolayer MoS₂ (MoS_{2- x} O_x ) with tunable doping levels is realized through an in situ chemical vapor deposition process. Interestingly, ultrafast infrared spectroscopy measurements and first-principles calculations reveal a reduction of bandgaps of monolayer MoS_{2- x} O_x with increased oxygen-doping levels. Field-effect transistors and logic devices are also fabricated based on these wafer-scale MoS_{2- x} O_x monolayers, and excellent electronic performances are achieved, exhibiting promise of such doped MoS₂ monolayers.