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

We proposed a tunable terahertz (THz) broadband absorber using monolayer MoS2 patterned with subwavelength Ring-Cross array. The combination of MoS2 micro-ring and MoS2 micro-cross exhibits excellent broadband absorption properties which can be continuously tuned by controlling the bias voltage to regulate the carrier concentration of MoS2. 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 MoS2 surface plasmons.