Investigation of dielectric constant of single layer MoS2 in visible light range based on Drude-Lorentz-Gaussian model

Understanding of optical properties of two dimensional MoS2 is important for its application in optoelectronics elements. Such properties can be determined by acceding to the permittivity function of the layer. The band gap of the MoS2 layer is in the range of 300 nm to 900 nm which is suitable for visible range. In this paper, the permittivity function is extracted by using Drude-Lorentz-Gaussian model which shows good consistency with experimental results. We show that the effect of Gaussian component supports the major carrier response of the permittivity function and each of Lorentz equations support oscillating behavior with small amplitude peaks in the imaginary part of the permittivity. As the permittivity response depends on the Fermi energy and temperature, we study the dielectric response at different temperatures and constant Fermi energy level and show that permittivity response increases with teperature around the peaks.