An efficient Terahertz rectifier on the graphene/SiC materials platform

Abstract

We present an efficient Schottky-diode detection scheme for Terahertz (THz) radiation, implemented on the material system epitaxial graphene on silicon carbide (SiC). It employs SiC as semiconductor and graphene as metal, with an epitaxially defined interface. For first prototypes, we report on broadband operation up to 580 GHz, limited only by the RC circuitry, with a responsivity of 1.1 A/W. Remarkably, the voltage dependence of the THz responsivity displays no deviations from DC responsivity, which encourages using this transparent device for exploring the high frequency limits of Schottky rectification in the optical regime. The performance of the detector is demonstrated by resolving sharp spectroscopic features of ethanol and acetone in a THz transmission experiment.

100 GHz zinc oxide Schottky diodes processed from solution on a wafer scale

“…These values are much higher than the ones reported recently for MoS 2 flexible rectifiers (4.7 A W −1 ; ref. 21 ) and similar to those of SiC-graphene Schottky diodes 7 .…”

“…Their unipolar operation, involving only majority carriers, means that negligible storage of excess minority carriers occurs, leading to small capacitances that can further boost their operating frequency. Terahertz rectifiers based on a graphene-SiC materials platform were recently reported 7 . However, the high temperatures involved in their fabrication (thermal annealing at 1,700 °C) renders the technology impractical for large-volume, inexpensive applications, and incompatible with flexible commodity substrate materials, such as polymers.…”

Towards white light laser emission based on strained Poly:(Si/Ge)

“…The gure shows that there is no avalanche effect in the reverse biasing of the prepared junctions and a very small dark current in the order of 10 − 4 A. This makes the junctions able to use in recti cation applications [5,41]. The ideality factor n is calculated using Schottky equation from the plot of Ln I versus V as shown in Fig.…”

2D THz Optoelectronics

“…[ 51 ] Another way of utilizing rectification with Schottky contacts has been realized in detectors where graphene serves as a metal layer and n‐doped SiC as the semiconductor material. [ 52 ] This Schottky rectifier with epitaxially defined interface is connected to a logarithmic periodic antenna.…”