Light absorption optimization in two-dimensional transition metal dichalcogenide van der Waals heterostructures

Abstract

Heterostructures of two-dimensional transition metal dichalcogenides (TMDCs) have recently received an upsurge of attention for application in optoelectronics. In this paper, we demonstrate efficient absorber van der Waals heterostructures in a form of air/hetero-TMDCs/substrate with various TMDC monolayers (MoSe2, WSe2, MoS2, and WS2). The dielectric permittivity of individual TMDC monolayers is determined using the Lorentz model. The absorption response of the designed heterostructure-TMDCs is determined by using the transfer matrix method. The effects of light polarization, angle of incident, and substrate on the absorption response are investigated. Finally, MoSe2/MoS2 and WS2/MoSe2 heterostructures on the SiO2(90 nm)/Si substrate are found to have absorption over 30% in a broadband wavelength range and in a wide incident angle, both useful designs for optoelectronic applications.