Misorientation-angle-dependent electrical transport across molybdenum disulfide grain boundaries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 26813605.
- Also identified by DOI 10.1038/ncomms10426 and PMC identifier 4737806.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Grain boundaries in monolayer transition metal dichalcogenides have unique atomic defect structures and band dispersion relations that depend on the inter-domain misorientation angle. Here, we explore misorientation angle-dependent electrical transport at grain boundaries in monolayer MoS2 by correlating the atomic defect structures of measured devices analysed with transmission electron microscopy and first-principles calculations. Transmission electron microscopy indicates that grain boundaries are primarily composed of 5-7 dislocation cores with periodicity and additional complex defects formed at high angles, obeying the classical low-angle theory for angles <22°. The inter-domain mobility is minimized for angles <9° and increases nonlinearly by two orders of magnitude before saturating at ∼ 16 cm(2) V(-1) s(-1) around misorientation angle ≈ 20°. This trend is explained via grain-boundary electrostatic barriers estimated from density functional calculations and experimental tunnelling barrier heights, which are ≈ 0.5 eV at low angles and ≈ 0.15 eV at high angles (≥ 20°).