Graphene field effect transistors as room-temperature Terahertz detectors

TL;DR

This paper presents graphene-based field-effect transistors that operate efficiently as room-temperature Terahertz detectors, offering promising applications in fast imaging and sensing in the THz spectrum.

Contribution

The study demonstrates the first practical room-temperature THz detectors using antenna-coupled graphene FETs with high sensitivity and real-world applicability.

Findings

Operates at 0.3 THz with noise equivalent power < 30 nW/Hz^(1/2)

Uses non-linear FET response to oscillating radiation

Suitable for large-area, fast imaging applications

Abstract

The unique optoelectronic properties of graphene [1] make it an ideal platform for a variety of photonic applications [2], including fast photodetectors [3], transparent electrodes [4], optical modulators [5], and ultra-fast lasers [6]. Owing to its high carrier mobility, gapless spectrum, and frequency-independent absorption coefficient, it has been recognized as a very promising element for the development of detectors and modulators operating in the Terahertz (THz) region of the electromagnetic spectrum (wavelengths in the hundreds of micrometers range), which is still severely lacking in terms of solid-state devices. Here we demonstrate efficient THz detectors based on antenna-coupled graphene field-effect transistors (FETs). These exploit the non-linear FET response to the oscillating radiation field at the gate electrode, with contributions of thermoelectric and photoconductive origin. We demonstrate room temperature (RT) operation at 0.3 THz, with noise equivalent power (NEP) levels < 30 nW/Hz^(1/2), showing that our devices are well beyond a proof-of-concept phase and can already be used in a realistic setting, enabling large area, fast imaging of macroscopic samples.