High-Responsivity Graphene/InAs Nanowire Heterojunction Near-Infrared Photodetectors with Distinct Photocurrent On/Off Ratios

Abstract

Graphene is a promising candidate material for high-speed and ultra-broadband photodetectors. However, graphene-based photodetectors suffer from low photoreponsivity and I(light)/I(dark) ratios due to their negligible-gap nature and small optical absorption. Here, a new type of graphene/InAs nanowire (NW) vertically stacked heterojunction infrared photodetector is reported, with a large photoresponsivity of 0.5 AW(-1) and I(light)/I(dark) ratio of 5 × 10(2), while the photoresponsivity and I(light)/I(dark) ratio of graphene infrared photodetectors are 0.1 mAW(-1) and 1, respectively. The Fermi level (E(F)) of graphene can be widely tuned by the gate voltage owing to its 2D nature. As a result, the back-gated bias can modulate the Schottky barrier (SB) height at the interface between graphene and InAs NWs. Simulations further demonstrate the rectification behavior of graphene/InAs NW heterojunctions and the tunable SB controls charge transport across the vertically stacked heterostructure. The results address key challenges for graphene-based infrared detectors, and are promising for the development of graphene electronic and optoelectronic applications.

A self-powered high-performance graphene/silicon ultraviolet photodetector with ultra-shallow junction: breaking the limit of silicon?

“…To the best of our knowledge, this is one of the shortest decay time reported for non-waveguide Gr/Si UV photodetectors. 57,58 We believe that the response time of the Gr/Si UV photodetector is largely limited by the circuit time constant τ~R s C, where R s is the serial resistance and C is the total parasitic capacitance. We use R s~2 00 Ω as derived from the forward J-V curve, and the measured C is 16 pF for an effective junction area of 0.0225 mm 2 at V b = 0.0 V. Thus, τ c is calculated to be~3.2 ns, close to the experimentally measured decay time.…”

Surface Plasmon-Enhanced Nano-photodetector for Green Light Detection

“…One can see clearly that both devices can be reversibly switched between high and low resistance states, with excellent reproducibility and stability. Notably, the dark current is slightly increased from 0.96 to 1.42 nA due to the charge transfer as a result of difference in work function [15,33]. What is more, the photocurrent for AuNPs@ZnTeNW is increased by sevenfold from 17.7 to 142 nA, yielding an increase of on/off ratio from 18.4 to 98.6.…”

“…LSPR effect has proved to be a highly reliable and efficient sensing strategy that can provide a noninvasive, label-free means of detection in real time [4,5]. In addition, LSPR effect has also been utilized as an approach to localize incident light at nanoscale level for improving light confinement when designing high-performance optoelectronic device [6,7], such as photovoltaic devices [8][9][10], light emitting diode (LEDs) [11,12], photodetector [13][14][15], optical waveguide [16,17], electrochromic devices [18], and thermoelectric devices [19,20].…”

Controllable Fabrication of Nanostructured Graphene Towards Electronics

“…[ 176 ] Furthermore, as shown in Figure 19 e, FETs based on graphene/ InAs nanowire heterostructures can be applied to near-infrared photodetectors which had a much larger photoresponsivity and light/dark current ratio. [ 177 ] Though graphene-based FETs are widely used due to the high intrinsic mobility of graphene, there are still many limitations. The defect of graphene could result in poor contact and charge trapping between graphene and dielectric layer, which could have negative effects on the properties of the electronics.…”