Microdisk array based Weyl semimetal nanofilm terahertz detector

High-performance terahertz wave detectors at room temperature are still urgently required for a wide range of applications. The available technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, complicated structure, and high noise equivalent power (NEP). Here, we have demonstrated a Weyl semimetal surface plasmon-enhanced high-performance terahertz wave detectors which are based on microdisk array deposited WTe₂ nanofilm epitaxially grown on GaN substrate for room temperature operation. With the microdisk array combined the WTe₂ layer, strong terahertz wave surface plasmon polaritons can be generated at the WTe₂-air interfaces, which results in significant improvement in detecting performance. For the 40 μm diameter microdisk array, a detectivity (D ^*) of 5.52 × 10¹² cm Hz^1/2 pW^-1 at 0.1 THz is achieved at room temperature. In addition, the responsivity (R _A) of 8.78 A W^-1 is also obtained. Such high-performance millimeter and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing.