Edge states of two-dimensional materials

Single layers of atomic thickness such as graphene, molybdenum disulfide and other transition metal dichalgogenides (TMDs) display unique electronic properties which depend on composition, dimensionality, strain, defects, chemical modification and nanostructuring, so that they may be engineered for specific applications. Intensive efforts to use two-dimensional (2D) materials in a wide range of technologies highlight the importance of edges in nanoribbons and nanoflakes. We will present theoretical results based on density functional theory calculations combined with simple models which clarify the effect of strain on TMD electronic and dielectric properties [1], the role of the metallic edge states in these otherwise semiconducting materials, especially in quasi-1D and 0D systems, and nanostructure stability [2]. The common origin of the edge states in TMD and graphene nanoribbons, as well as their main differences, will also be discussed.

1. A.E. Maniadaki et al, Solid State Commun. 227, 33 (2016).
2. D. Davelou et al, Phys. Rev. B 96, 165436 (2017).