MoTe₂ Microfilm Terahertz Detector at Room Temperature

Abstract

Terahertz detectors are attracting widespread attention due to the special frequency of terahertz waves between microwaves and infrared waves. However, the problems such as small detection area, difficulty in repeatable preparation, high noise equivalent power as well as the requirement for cooling system still exist. In order to fulfill this requirement, Weyl semimetal MoTe2 was chosen as the active layer in this work due to its narrow bandgap and Weyl-point enhancement. In this work, the fabircation of high-quality and large-scale (1 mm $\times$ 6.3 mm) MoTe2-based THz detectors realized with the magnetron sputtering deposition method. Addtionally, with an external voltage applied, our device exhibits obvious excitation of light current for THz detection and demonstrates a photoresponse of 2.65 A/W and a noise equivalent power of $16.84 \times 10^{-12}$ W Hz$^{-1/2}$ under the illumination of 0.1 THz wave at room temperature. Our research paves the way to the fabrication of large-scale THz detectors, also proves that the Weyl semimetal possess enormous potential in long-wave detection.