40 research outputs found
Electrically-induced n-i-p junctions in multiple graphene layer structures
The Fermi energies of electrons and holes and their densities in different
graphene layers (GLs) in the n- and p-regions of the electrically induced n-i-p
junctions formed in multiple-GL structures are calculated both numerically and
using a simplified analytical model. The reverse current associated with the
injection of minority carriers through the n- and p-regions in the
electrically-induced n-i-p junctions under the reverse bias is calculated as
well. It is shown that in the electrically-induced n-i-p junctions with
moderate numbers of GLs the reverse current can be substantially suppressed.
Hence, multiple-GL structures with such n-i-p junctions can be used in
different electron and optoelectron devices.Comment: 7 pages, 6 figure
Effect of electron thermal conductivity on resonant plasmonic detection in the metal/black-AsP/graphene FET terahertz hot-electron bolometers
We analyze the two-dimensional electron gas (2DEG) heating by the incident
terahertz (THz) radiation in the field-effect transistor (FET) structures with
the graphene channels (GCs) and the black-phosphorus and black-arsenic gate
barrier layers (BLs). Such GC-FETs can operate as bolometric THz detectors
using the thermionic emission of the hot electrons from the GC via the BL into
the gate. Due to the excitation of plasmonic oscillations in the GC by the THz
signals, the GC-FET detector response can be pronouncedly resonant, leading to
elevated values of the detector responsivity. The lateral thermal conductivity
of the 2DEG can markedly affect the GC-FET responsivity, in particular, its
spectral characteristics. This effect should be considered for the optimization
of the GC-FET detectors.Comment: 9 pages, 3 figure
Terahertz bolometric detectors based on graphene field-effect transistors with the composite h-BN/black-P/h-BN gate layers using plasmonic resonances
We propose and analyze the performance of terahertz (THz) room-temperature
bolometric detectors based on the graphene channel field-effect transistors
(GC-FET). These detectors comprise the gate barrier layer (BL) composed of the
lateral hexagonal-Boron Nitride black-Phosphorus/ hexagonal-Boron Nitride
(h-BN/b-P/h-BN) structure. The main part of the GC is encapsulated in h-BN,
whereas a short section of the GC is sandwiched between the b-P gate BL and the
h-BN bottom layer. The b-P gate BL serves as the window for the electron
thermionic current from the GC. The electron mobility in the GC section
encapsulated in h-BN can be fairly large. This might enable a strong resonant
plasmonic response of the GC-FET detectors despite relatively lower electron
mobility in the GC section covered by the b-P window BL. The narrow b-P window
diminishes the Peltier cooling and enhances the detector performance. The
proposed device structure and its operation principle promote elevated values
of the room-temperature GC-FET THz detector responsivity and other
characteristics, especially at the plasmonic resonances.Comment: 9 pages, 8 figure