Abstract
Grain boundaries in two-dimensional transition-metal dichalcogenides can strongly affect the transport properties by reducing the electron mobility or allowing gap conduction through extended grain boundary states. Here, by combining advanced modeling tools–density-functional-theory-calibrated tight-binding Hamiltonians and Green's function techniques–we investigate transport along and across mirror twin grain boundaries in . Our results show that the grain boundary conductive channels are strongly affected by sulfur vacancies, while short-range Anderson disorder has a moderate impact, which we quantitatively analyze, and long-range disorder has a very weak effect. As for transport across the grain boundaries, the system conductance turns out to be less than half that for the pristine system, and the spin-orbit coupling and intervalley scattering are found to play an important role. Our findings are beneficial to the understanding and the prediction of the impact of mirror twin grain boundaries in the transport phenomena and could be of help in designing electronic devices based on transition metal dichalcogenides.
5 More- Received 13 September 2019
- Revised 8 November 2019
DOI:https://doi.org/10.1103/PhysRevB.100.235403
©2019 American Physical Society