Tunable terahertz broadband absorber based on MoS2 ring-cross array structure

Abstract

We proposed a tunable terahertz (THz) broadband absorber using monolayer MoS 2 patterned with subwavelength Ring-Cross array. The combination of MoS 2 micro-ring and MoS 2 micro-cross exhibits excellent broadband absorption properties which can be continuously tuned by controlling the bias voltage to regulate the carrier concentration of MoS 2 . Detailed investigation shows that the continuous absorption can be caused by three different dipole resonance excitation modes. Furthermore, the absorber is polarization independent and incidence angle insensitive due to the rotated symmetry of the unit cell. Additionally, a wide absorption frequency range from 1.2 THz to 2.67 THz with a high absorption above 90%, and the absorption bandwidth (ABW) can reach 76.0% under the optimal absorption condition can be achieved. This structure may provide a new direction for the design of tunable THz devices with MoS 2 surface plasmons. • A tunable terahertz broadband absorber was proposed using monolayer MoS 2 patterned with subwavelength Ring-Cross array. • Continuously tuning properties can be achieved by controlling bias voltage to regulate the carrier concentration of MoS 2 . • The continuous absorption can be caused by three different dipole resonance excitation modes. • The absorber is polarization independent and incidence angle insensitive for TM or TE mode. • A wide absorption frequency range from 1.2 THz to 2.67 THz and the relative absorption bandwidth can reach 76.0%.