Graphene field-effect transistors as room-temperature terahertz detectors

Abstract

The unique optoelectronic properties of graphene make it an ideal platform for a variety of photonic applications, including fast photodetectors, transparent electrodes in displays and photovoltaic modules, optical modulators, plasmonic devices, microcavities, and ultra-fast lasers. Owing to its high carrier mobility, gapless spectrum and frequency-independent absorption, graphene is a very promising material for the development of detectors and modulators operating in the terahertz region of the electromagnetic spectrum (wavelengths in the hundreds of micrometres), still severely lacking in terms of solid-state devices. Here we demonstrate terahertz detectors based on antenna-coupled graphene field-effect transistors. These exploit the nonlinear response to the oscillating radiation field at the gate electrode, with contributions of thermoelectric and photoconductive origin. We demonstrate room temperature operation at 0.3 THz, showing that our devices can already be used in realistic settings, enabling large-area, fast imaging of macroscopic samples.

Characterization of Al2O3 gate dielectric for graphene electronics on flexible substrates

“…The leakage current is attributed to a combination of tunneling current and charging current. It is less than 100 μA/cm 2 when the gate voltage is 5 V, which is negligible compared to drain current in GFETs and photocurrent in terahertz detectors based on GFETs [11]. The breakdown electric field is about 5 mV/cm, which is similar to reported Al 2 O 3 ALD films on silicon [12].…”

TERA-MIR radiation: materials, generation, detection and applications

“…The limits of QCL science and technology (Miriam 2012) will be investigated combining academic and industrial teams. Graphene is also emerging as a spectacular THz material and we plan to further stimulate joint efforts within the action (Vicarelli et al 2012). Finally, integrating MIR components on a single chip to create a sensor system-on-a-chip and evaluating it is a task are also spectacular goals that we hope to see come through in the near future and that will be stimulated by our network.…”

Surface Plasmon Polariton Graphene Photodetectors

“…The interference between surface plasmon polaritons and the incident wave introduces new functionalities, such as light flux attraction or repulsion from the contact edges, enabling the tailored design of the photodetector's spectral response. This architecture can also be used for surface plasmon bio-sensing with direct-electricreadout, eliminating the need of complicated optics.Graphene-based photodetectors (PDs) [1,2] have been reported with ultra-fast operating speeds (up to 262GHz from the measured intrinsic response time of graphene carriers [3]) and broadband operation from the visible and infrared [3][4][5][6][7][8][9][10][11][12][13][14][15][16] up to the THz [17][18][19]. The simplest graphene-based photodetection scheme relies on the metal-graphene-metal (MGM) architecture [5,7,8,11,[20][21][22], where the photoresponse is due to a combination of photo-thermoelectric and photovoltaic effects [5,7,8,11,[20][21][22].…”