Outstanding gas-sensing performance of graphene/SnO2 nanowire Schottky junctions

Abstract

Schottky junctions (SJ) are considered devices for sensing applications due to their unique properties. Herein, we report on the design, facile fabrication, and outstanding NO2 gas sensing properties of monolayer graphene (GP)/SnO2 nanowire (NW) SJ devices. The devices were prepared by directly growing single crystal SnO2 NWs on interdigitated Pt electrodes via thermal evaporation, followed by transferring a GP layer grown by chemical vapor deposition on top of the NW chip. The SJ-based sensor showed a reversible response to NO2 gas at concentrations of ppb levels with detection limits of about 0.024 ppb at a low operating temperature of 150 °C and bias voltage (1 V) with a response/recovery time of less than 50 s. The outstanding gas-sensing characteristics of the device were attributed to tuning the Schottky barrier height and barrier width at the tiny area of contact between GP and SnO2 NW through the adsorption/desorption of gas molecules.

Graphene Schottky diodes: An experimental review of the rectifying graphene/semiconductor heterojunction

“…The tuning the SBH and barrier width at the tiny area of contact between graphene and SnO2 nanowires through the adsorption/desorption of gas molecules is at the origin of the outstanding NO2 gas sensing properties of monolayer G/SnO2 nanowire Schottky junction devices presented in Ref. [238]. The devices were prepared by directly growing single crystal SnO2 nanowires on interdigitated Pt electrodes via thermal evaporation.…”

Synthesis and Characterization of Nanocomposites Tin Oxide-Graphene Doping Pd Using Polyol Method

“…However, SnO2-Pd nanomaterial still shows some drawbacks when applied as gas sensors, such as high working temperature (350 °C) and high resistance (~100 MQ). On the other hand, graphene is also widely applied in gas sensors such as in NO2 gas sensor [16][17][18][19], methane [11], alcohol [20][21][22] and vaporized water. Graphene shows some excellent performances such as ultrahigh sensitivity at extremely low concentrations, high specificity, fast response and recovery, low power consumption, room temperature operation and good reversibility [16].…”

Rheotaxially Grown and Vacuum Oxidized SnOx Nanolayers for NO2 Sensing Characteristics at ppb Level and Room Temperature

“…In order to discuss theoretically the smallest amount of NO 2 that could be detected, the signal to noise ratio was taken into account according to the International Union of Pure and Applied Chemistry recommendations [33], which specify that for reliable measurement the signal to noise has to be larger than 3. The procedure applied within this study, previously proposed by Li et al [34] and successfully applied in literature [21,[35][36][37] is given by Equation (1):…”