title: A new (2 × 1) dimerized structure of monolayer 1T-molybdenum disulfide, studied from first principles calculations.
abstract: The geometric, electronic, and vibrational properties of monolayer 1T-molybdenum disulfide (MoS2) have been studied by using the first-principles calculations. A new (2 × 1) dimerized structure of monolayer 1T-MoS2, called as 1T'-MoS2, has been found, which is semi-conducting and more stable than the previously found ones. Interestingly, a semiconductor-metal transition is found under an applied tensile strain at about 4% or a compressive strain at about 5%, while the dimerization structure has been retained under both the tensile and compressive strains. Moreover, the vibrational properties of three kinds of monolayer MoS2, i.e., the 1T-MoS2, 1T'-MoS2, as well as the 1H-MoS2, have been studied, based upon which the different isomer structures of monolayer MoS2 can be easily distinguishable in experiments by analyzing their characteristic Raman spectra.
authors.affiliation: Group of Computational Condensed Matter Physics, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Hu
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Jinming
authors.initials: J
authors.lastname: Dong