Interface Defect Engineering of a Large‐Scale CVD‐Grown MoS2 Monolayer via Residual Sodium at the SiO2/Si Substrate

Abstract

AbstractAlkali metal halide‐assisted chemical vapor deposition (CVD) methods can produce wafer‐scale uniform monolayer transition metal dichalcogenides (TMDs). Further defect engineering is necessary to obtain high‐performance functional devices. While defect engineering has focused on the surface of the monolayer TMDs or the contact property, interface defect engineering is rare and non‐trivial. Based on a NaCl‐assisted CVD‐grown large‐scale uniform MoS2 monolayer on SiO2/Si substrate, a trace amount of Na cations is present, residing at the SiO2 substrate during the CVD‐growth process and contributes to the n‐type doping into the supported monolayer MoS2. Furthermore, the residual Na cations are electrically moved toward the bottom side of monolayer MoS2 to passivate the interfacial defects.