Y. Zhang, M.S. Shur
Rensselaer Polytechnic Institute,
Keywords: plasmonic FETs, THz detector, graphene, hydrodynamic model, infrared frequency
Summary:We compare the limiting values of plasma frequency and the detection performance of the gated and ungated Si, GaN, InGaAs, diamond, and graphene gated and ungated TeraFETs. This analysis is performed in the frame of a hydrodynamic model considering the viscosity effect and assuming that the plasma frequency should be smaller than the optical phonon frequency. Such comparison shows that the plasma frequencies in the gated and ungated monolayer and bilayer graphene TeraFETs could reach the infrared range, which is much higher than for other more traditional materials. This enables using plasmonic graphene TeraFETs to operate as detectors, frequency multipliers, mixers, amplifiers, and sources up to infrared frequencies. Graphene detectors also exhibit a relatively high detection responsivity and a short response time, favoring the continuous wave and pulse detection applications. The high values of the plasma velocity and long momentum relaxation times in graphene allow reaching high plasma frequencies in much longer graphene channels than for more conventional plasmonic TeraFETs.