Energetics and electronic structures of MoS2 nanoribbons

We study the energetics and electronic structures of MoS2 nanoribbons with clean armchair, chiral, and zigzag edges by conducting the first-principle total energy calculations based on the density functional theory. Our calculations showed that the nanoribbon with zigzag edges is the most stable among the ribbons studied here. The ribbons with armchair or near armchair edges are semiconductors with a direct band gap at the Gamma point, owing to the large edge relaxation reducing the unsaturated nature of edge atoms, while the ribbons with zigzag and near zigzag edges are metals with the finite density of state at the Fermi level. According to the asymmetric atomic arrangement in ribbons with the chiral and zigzag edges, they have polarity across the ribbon, which monotonically increase with increasing edge angle. (C) 2019 The Japan Society of Applied Physics