Carbon Nanotube Terahertz Detector

TLDR

Terahertz technologies hold promise for medicine, bioengineering, astronomy, environmental monitoring, and communications, yet solid‑state devices for this spectral region remain elusive. The study develops a powerless, compact, broadband, flexible, large‑area, polarization‑sensitive carbon‑nanotube THz detector that operates at room temperature. The detector’s performance was characterized thermoelectrically and opto‑thermally, revealing a photothermoelectric response driven by plasmonic absorption and antenna effects, and indicating that thermal management and Seebeck coefficient engineering can further improve it. The detector achieves broadband sensitivity across the THz gap, with responsivities up to ~2.5 V/W and polarization ratios up to ~5:1, confirming its photothermoelectric response originates from plasmonic absorption and antenna effects.

Abstract

Terahertz (THz) technologies are promising for diverse areas such as medicine, bioengineering, astronomy, environmental monitoring, and communications. However, despite decades of worldwide efforts, the THz region of the electromagnetic spectrum still continues to be elusive for solid state technology. Here, we report on the development of a powerless, compact, broadband, flexible, large-area, and polarization-sensitive carbon nanotube THz detector that works at room temperature. The detector is sensitive throughout the entire range of the THz technology gap, with responsivities as high as ∼2.5 V/W and polarization ratios as high as ∼5:1. Complete thermoelectric and opto-thermal characterization together unambiguously reveal the photothermoelectric origin of the THz photosignal, triggered by plasmonic absorption and collective antenna effects, and suggest that judicious design of thermal management and quantum engineering of Seebeck coefficients will lead to further enhancement of device performance.