Introducing a novel approach to linear and nonlinear electrical conductivity of MoS2

Abstract

In regards to the interaction between 2D materials and laser beams, electrical conductivity is the cornerstone due to the fact that the optical absorption is correlated to electrical and opto-electrical properties. In this paper, the linear electrical conductivity (σ(1)) and nonlinear properties (σ(2) and σ(3)) for MoS2 will be investigated theoretically. So as to study the linear electro-optics effect (Pockels effect) in monolayer and the quadratic electro-optics (Kerr effect) in a bilayer of MoS2, σ(2) and σ(3) are derived, respectively. In this work, in order to achieve the σ(1), σ(2) and σ(3), we calculate the first, second and third order of susceptibility of MoS2 (χ(1), χ(2) and χ(3)) by implication of the first order electrical permeability of MoS2 (ɛ(1)), which has been reported in preceding studies. In the next step, by taking advantage of ɛ(E) = ɛ(1) + χ(2)|E| and σ(E) = σ(1) + σ(2)|E|, which express the linear electro-optics (Pockels) effect, the second order of electrical conductivity (σ(2)) can be acquired. Moreover, by considering ɛ(E) = ɛ(1) + χ(3)|E|2 and σ(E) = σ(1) + σ(3)|E|2 as the embodiment of the quadratic electro-optics (Kerr) effect, the third order of electric conductivity (σ(3)) are being calculated. Having this potential for calculating the optical nonlinear response in TMDs would lay the groundwork for designing and engineering a new generation of nonlinear devices premised upon TMDs.