Line Defects in Molybdenum Disulfide Layers

Abstract

Layered molecular materials and especially MoS2 are already accepted as\npromising candidates for nanoelectronics. In contrast to the bulk material, the\nobserved electron mobility in single-layer MoS2 is unexpectedly low. Here we\nreveal the occurrence of intrinsic defects in MoS2 layers, known as inversion\ndomains, where the layer changes its direction through a line defect. The line\ndefects are observed experimentally by atomic resolution TEM. The structures\nwere modeled and the stability and electronic properties of the defects were\ncalculated using quantum-mechanical calculations based on the\nDensity-Functional Tight-Binding method. The results of these calculations\nindicate the occurrence of new states within the band gap of the semiconducting\nMoS2. The most stable non-stoichiometric defect structures are observed\nexperimentally, one of which contains metallic Mo-Mo bonds and another one\nbridging S atoms.\n