Double bow-tie antenna based 2D MoTe2 detector for terahertz wave detection

The wide band-gap of two-dimensional (2D) MoTe2 makes it impossible to directly detect terahertz waves. In this paper, a planar THz antenna-based 2D MoTe2 detection structure is proposed for THz detection. Numerical study shows that the designed and optimized double bow-tie Au planar antennas structure achieves extremely strong terahertz wave coupling in a narrow band at 0.1THz, and the absorption reaches 99.99%, and the enhanced local field distributed in central region of antennas. The absorption of the double bow-tie antennas is 1.3 times than that of the single bow-tie antennas with the same main structure parameters. When combine the double bow-tie antennas with 2D MoTe2, 0.1THz wave was detected by them under a small bias applied on the antennas. The carriers among the detector are brought about by the injected electrons from the Au antennas by the electromagnetic-induced well. The experimental results show that the detection structure has good ohmic characteristics, and the detection responsivity is 0.02mA/W, and the specific detection rate is 4.67×10 5Jones. This kind of antenna-based 2D materials terahertz wave detector can easily adjust detection wavelength by changing structure parameters of antennas, which has potential applications in terahertz detection technology.