Plasmonic Terahertz Detector Based on Graphene Split-Gate FET with Nanoconstrictions in Lateral p-n Junction Depletion Region

Due to their unique properties, graphene layers (GLs), graphene bilayers (GBLs), graphene nanoribbons (GNRs),perforated graphene layers (PGLs) with nanoconstrictions, and other graphene-based structures can be used as buildingblocks for different electron, infrared (IR) and terahertz (THz) devices. In particular, these devices include IR and THzdetectors, sources, frequency converters, and modulators and operate using the interband and intraband transitions, tun-neling and plasmonic effects graphene. In the present communication, we propose the concept of the THz detector basedon the GL split-gate field-effect transistor (FET) with the electrically induced lateral perforated p-n-junction (PGL-FET),partitioned into an array of nanoconstrictions, and evaluate the PGL-FET-detector performance.

The operation of the PGL-FET detectors is enabled by the non-linearity of the p-n-junction current-voltage characteristics leadingto the rectification of the ac current produced by the THz radiation.The hole and electron two-dimensional systems induced under thegates by the applied gate voltages Vp and Vn of different polarity play the role of the plasmonic resonant cavities [1]. The resonant properties of the plasmonic cavities in FETs were used in the real-ization of different highly effective THz detectors operating at room temperature [2], in particular, using GL-FETs [3]. Since the GL inthe p-n-junction depletion region is perforated, this region consists of an array of nanoconstrictions, that results in the energy gap opening and formation of the barrier for the electrons and holes. The lattersuppresses the interband tunneling and strongly affects the linear and nonlinear characteristics of the p-n-junction (as in FETs based on the standard materials