Polarity-Reversed Robust Carrier Mobility in Monolayer MoS₂ Nanoribbons

Abstract

Using first-principles calculations and deformation potential theory, we investigate the intrinsic carrier mobility (μ) of monolayer MoS₂ sheet and nanoribbons. In contrast to the dramatic deterioration of μ in graphene upon forming nanoribbons, the magnitude of μ in armchair MoS₂ nanoribbons is comparable to its sheet counterpart, albeit oscillating with ribbon width. Surprisingly, a room-temperature transport polarity reversal is observed with μ of hole (h) and electron (e) being 200.52 (h) and 72.16 (e) cm² V^–1s^–1 in sheet, and 49.72 (h) and 190.89 (e) cm² V^–1 s^–1 in 4 nm nanoribbon. The high and robust μ and its polarity reversal are attributable to the different characteristics of edge states inherent in MoS₂ nanoribbons. Our study suggests that width reduction together with edge engineering provide a promising route for improving the transport properties of MoS₂ nanostructures