MoS2 field-effect transistor with graphene contacts

Abstract

Tailoring the electronic properties of molybdenum disulfide (MoS₂) is essential to obtain the best performance of its electronic and optoelectronic devices. Here, we report a simple methodology to improve the performance of bi-layer (BL) MoS₂ field-effect transistors (FETs) by a combination of nitrogen (N₂) gas and deep-ultraviolet (DUV) light treatment. Threshold voltages of BL MoS₂ FETs shifted towards a negative gate voltage after treatment with N₂ gas in the presence of DUV light. The charge-carrier mobility of BL MoS₂ was improved significantly after exposure to N₂ gas under DUV light irradiation. The carrier density of BL MoS₂ was enhanced after treatment with N₂ gas in the presence of DUV light. We believe that our work may also help improve the performance of other two-dimensional nanomaterials.