The effect of uniaxial strain on the optical properties of monolayer molybdenum disulfide

In this paper, we present our numerical studies on the optical properties of the monolayer molybdenum disulfide (MoS2). In order to calculate the Hamiltonian of the MoS2 structure, an atomistic tight binding (TB) model is employed, which includes the nearest neighbors. The tight binding model takes into account d(z2), d(xy), and d(x2-y2) orbitals of the Mo atoms and p(x), p(y), p(z) orbitals of the S atoms. In addition, the dielectric function and the optical conductivity of a monolayer MoS2 is calculated based on the atomistic tight binding Hamiltonian. It is found that the absorption spectrum can be characterized by two peaks, associated with energies which provide optical applications in the range of the visible regime. Uniaxial tensile strain leads to a red shift of the peaks in the spectrum of the dielectric function. The amount of the shift varies with the tensile strain almost linearly. In contrast, an applied compressive strain along the direction of the zigzag edge gives rise to a blue shift of the dielectric function.