High frequency electromagnetic detection by nonlinear conduction modulation in graphene nanowire diodes

Abstract

We present graphene nanowires implemented as dispersion free self switched microwave diode detectors. The microwave properties of the detectors are investigated using vector corrected large signal measurements in order to determine the detector responsivity and noise equivalent power (NEP) as a function of frequency, input power, and device geometry. We identify two distinct conductance nonlinearities which generate detector responsivity: an edge effect nonlinearity near zero bias due to lateral gating of the nanowire structures, and a velocity saturation nonlinearity which generates current compression at high power levels. The scaling study shows that detector responsivity obeys an exponential scaling law with respect to nanowire width, and a peak responsivity (NEP) of 250 V/W (50 pW/ ffiffiffiffiffiffi Hz p ) is observed in detectors of the smallest width. The results are promising as the devices exhibit responsivities which are comparable to state of the art self switched detectors in semiconductor technologies. V C 2015 AIP Publishing LLC.

Estimation of intrinsic and extrinsic capacitances of graphene self-switching diode using conformal mapping technique

“…. The measured results in figure 1(b) yield a γ = 0.686 V -1 , accordingly βV = 68.6 V/W, and these values are well in accordance with previously reported values for similar devices [36]. The intrinsic cut-off frequency (f = 1/2πRC) of 0.16 THz is estimated for the fabricated graphene SSD from the zero-bias resistance (36 kΩ) and extrinsic capacitance (2.76 × 10 -17 F), that can be improved further by employing wider vertical trenches which in turn reduces the extrinsic capacitance.…”

Low-Frequency Noise in Electric Double Layer InGaZnO Thin-Film Transistors Gated with Sputtered SiO2-Based Electrolyte

“…, where kB is the Boltzmann constant, T is the temeprature and R is the resistance of the detector [6]. At = −5.4 V and −0.2 V , the NEP are 18.2 pW/Hz 1/2 and 5.4 pW/Hz 1/2 , respectively.…”

“…Since then, there have been experiments showing their capability to operate at room temperature at high frequencies, up to and including terahertz (THz) [3]. They have been operated as microwave and THz detectors [4][5][6], and fabricated in other materials such as GaN [5], organic polymer [7], and zinc-oxide thin films [8].…”

“…SSDs fabricated from graphene (also known as graphene SSDs, GSSDs) have also been demonstrated [6,9,10], modelled [11], and simulated [12,13]. Due to the capability of SSDs constructed from InGaAs/InAlAs and other materials to operate at THz frequencies [4], and the greater carrier mobility in graphene, it is expected that GSSDs will also be capable of operating at THz frequencies.…”

Microwave Detection Using Two-Atom-Thick Self-Switching Diodes Based on Quantum Simulations and Advanced Circuit Models

“…In principle, an SSD could be modeled as a 2-D field-effect transistor (FET) [8], [9] with short-circuited gate and drain. This type of devices has been fabricated using various semiconductor and 2-D electron gas (2DEG)-like materials, like AlGaN/GaN [6], GaN [7], InAs [5], graphene [2], [10], [11], and molybdenum disulfide (MoS 2 ) [12], [13]. Nevertheless, to the authors' knowledge, no attempt has been made so far to fabricate an SSD based on a monolayer MoS 2 /monolayer graphene heterojunction, mostly due to: 1) the difficulties in the growth of MoS 2 at the wafer scale and 2) its low mobility [14].…”