Terahertz detection by epitaxial-graphene field-effect-transistors on silicon carbide

Abstract

We report on room temperature detection of terahertz radiation by means of antenna-coupled field effect transistors (FETs) fabricated using epitaxial graphene grown on silicon carbide. The achieved photoresponsivity (similar to 0.25 V/W) and noise equivalent power (similar to 80 nW/root Hz) result from the combined effect of two independent detection mechanisms: over-damped plasma wave rectification and thermoelectric effects, the latter ascribed to the presence of carrier density junctions along the FET channel. The calculated plasmonic and thermoelectric response reproduces qualitatively well the measured photovoltages; the experimentally observed sign-switch demonstrates the stronger contribution of plasmonic detection compared to the thermoelectric one. These results unveil the potential of plasmonic detectors exploiting epitaxial graphene on silicon carbide for fast large area imaging of macroscopic samples

Scalable synthesis of WS 2 on graphene and h-BN: an all-2D platform for light-matter transduction

“…The combination of a sudden evaporation of S at the growth temperature of 900°C and high reactant flow rates, were found to balance the competing processes of sublimation, reaction, transfer, diffusion and precipitation of the reactants in favor of fast and dense WS 2 growth. WS 2 synthesis was performed on h-BN flakes exfoliated on quartz, CVD graphene transferred on quartz, and epitaxial graphene on silicon carbide (SiC) [17,18]. The choice of transparent substrates anticipates the use of the investigated heterostacks for optoelectronic applications.…”

MBE growth of self-assisted InAs nanowires on graphene

“…Bilayer graphene, buffer layer, and QFMLG samples were obtained on the silicon-terminated face of insulating silicon carbide (4H-SiC (0001)) [CREE Inc.] in a resistively heated cold-wall reactor [Aixtron HT-BM] [33,34]. First, the SiC (0001) substrates were hydrogen-etched for 5 minutes at a temperature of about 1300 °C and a pressure of 450 mbar, in order to obtain atomically flat surfaces [35].…”

Enhanced electron-phonon coupling in graphene with periodically distorted lattice

“…The samples for the optical experiments were obtained by thermal decomposition of the silicon face of silicon carbide (SiC) [24]. In this case, the interface between bilayer graphene and the SiC substrate is formed by a carbon buffer layer.…”

“…We excited epitaxial bilayer graphene grown on SiC(0001) [24,25], both in and out of resonance with the in-plane bond-stretching E 1u phonon at 200 meV (6.3 µm wavelength). The electronic properties of the driven state were then measured with both TeraHertz time-domain spectroscopy (THz TDS, Fig.…”