Dual-Additive Assisted Chemical Vapor Deposition for the Growth of Mn-Doped 2D MoS2 with Tunable Electronic Properties

Abstract

Doping of bulk silicon and III-V materials has paved the foundation of the current semiconductor industry. Controlled doping of 2D semiconductors, which can also be used to tune their bandgap and type of carrier thus changing their electronic, optical, and catalytic properties, remains challenging. Here the substitutional doping of nonlike element dopant (Mn) at the Mo sites of 2D MoS₂ is reported to tune its electronic and catalytic properties. The key for the successful incorporation of Mn into the MoS₂ lattice stems from the development of a new growth technology called dual-additive chemical vapor deposition. First, the addition of a MnO₂ additive to the MoS₂ growth process reshapes the morphology and increases lateral size of Mn-doped MoS₂ . Second, a NaCl additive helps in promoting the substitutional doping and increases the concentration of Mn dopant to 1.7 at%. Because Mn has more valance electrons than Mo, its doping into MoS₂ shifts the Fermi level toward the conduction band, resulting in improved electrical contact in field effect transistors. Mn doping also increases the hydrogen evolution activity of MoS₂ electrocatalysts. This work provides a growth method for doping nonlike elements into 2D MoS₂ and potentially many other 2D materials to modify their properties.

Keywords: MoS 2; doping; dual-additive chemical vapor deposition; electronic properties; field effect transistors; hydrogen evolution reaction.