Hybridized Graphene Oxide FETs with Amplified Gas Sensitivity

Abstract

The current study concerns a new approach to achieve amplified gas sensitivity in hybrid graphene oxide (GO) based field effect transistors (FET) sensors. Chemically synthesized TiO 2 nanoparticles, WO 3 nanoflowers and Pd nanoparticles were used to functionalize GO channel which was then implemented in back gated FET structure sensors fabricated on SiO 2 /Si substrate. Morphology of pure and hybridized GO were characterized with field emission scanning electron microscopy. IDS-VGS characteristics of all the FET sensors were measured in air and 100 ppm of ethanol/acetone ambient. Interestingly, all the sensors exhibited a peak response magnitude at a particular VGS closed to the Dirac point. Therefore, to achieve a high sensitivity, transient response was measured at VGS≈VDirac, while VDS=1V (constant). ~49%, ~55%, ~229% and ~129% response towards 100 ppm of ethanol/acetone were recorded for pure GO, p-TiO 2 -GO, WO 3 - GO and Pd-GO sensors, respectively. The recorded responses at VGS≈VDirac were. 7,11,21 and 64 times amplified than that of the VGS=0. The amplified sensitivity was achieved by modulating the carrier concentration of GO channel through optimized gate electrostatic. The functionalization of GO with TiO 2 , WO 3 and Pd further enhanced the catalytic activity, selectivity, dissociative adsorption properties of the sensing channel towards different VOCs.