Transport properties of chemically synthesized MoS2 – Dielectric effects and defects scattering

We report on the electrical characterization of synthetic, large-area MoS2 layers obtained by the sulfurization technique. The effects ofdielectric encapsulation and localized defect states on the intrinsictransport properties are explored with the aid of temperature-dependent measurements. We study the effect ofdielectric environment by transferring as-grown MoS2films into differentdielectrics such as SiO2, Al2O3, HfO2, and ZrO2 with increasingdielectric permittivity. Electrical data are collected on a statistically-relevantdevice ensemble and allow to assessdevice performances on a large scale assembly. Ourdevices show relative in-sensitiveness ofmobility with respect todielectric encapsulation. We conclude that thedevice behavior is strongly affected by several scattering mechanisms of different origin that can completely mask any effect related todielectric mismatch. At low temperatures, conductivity of thedevices is thermally activated, a clear footprint of the existence of amobility edge separating extended states in the conduction band from impurity states in the band-gap.

Source: Applied Physics Letters - December 6, 2016 Category: Physics Authors: Massimo Mongillo, Daniele Chiappe, Goutham Arutchelvan, Inge Asselberghs, Marta Perucchini, Mauricio Manfrini, Dennis Lin, Cedric Huyghebaert and Iuliana Radu Source Type: research