Broadband terahertz complementary metamaterials absorber and modulator based on graphene/MoS 2 heterojunction

Abstract Metamaterials have been widely used in the field of terahertz (THz) to enhance the interaction between THz waves and materials. The 2D heterojunctions are deposited by two or more layers of different 2D materials, showing excellent optoelectronic properties. Among them, the heterojunction composed of graphene and molybdenum disulfide (MoS 2 ) presents unique photoelectric characteristics and adjustable bandgap characteristics. In this paper, a broadband THz complementary metamaterial absorber based on graphene and MoS 2 heterojunction is proposed and investigated. Through simulations, it has been found that the surface plasmon resonance assists the absorber to achieve more than 90% absorption in the frequency range of 2.1–3.9 THz at 0.9 eV graphene Fermi level. Meanwhile, the absorber shows the ability in absorption modulation. By adjusting the Fermi level of graphene, a maximum modulation depth of 75% and a maximum center frequency modulation depth of 13% can be obtained. This work has practical significance and value for the development of 2D heterojunction-based metamaterial in the development of multifunctional THz devices and provides a novel design strategy that combines the electrically tunable heterojunction with a complementary metamaterial resonator for terahertz broadband metamaterial absorbers and modulators.