Optical absorption in air/monolayer MoS2/S (SSiO2 or Si) trilayer stacks at oblique incidence

The monolayer MoS2 with strong light-matter interaction and optoelectronic properties is useful to design different optical devices such as photonic absorbers. In this paper, the MoS2 monolayer is sandwiched in the following stacks: SiO2/MoS2/air and Si/MoS2/air to study of increasing optical absorption. We study theoretically the absorption of these stacks as a function of polarization, incident angle and wavelength to reach the maximum value in the visible regime. The absorption intensity reaches to be as high as 65% for internal reflection and s polarization, around the blue wavelength for air/MoS2/SiO2 stack. Absorption behavior including maxima points as a function of wavelength is correlated with imaginary component of refractive index of the monolayer MoS2 except around critical angle. Our results recommend important role of internal and external reflection, cover and substrate layer, angle of incidence and polarization to design elements for optical energy harvesting applications.