Computational modeling of transport properties of decorated SWCNT: application in H 2 S gas sensor
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RESEARCH PAPER
Computational modeling of transport properties of decorated SWCNT: application in H2S gas sensor Sheida Bagherzadeh-Nobari
&
Kiarash Hosseini Istadeh & Reza Kalantarinejad
Received: 21 May 2020 / Accepted: 2 September 2020 # Springer Nature B.V. 2020
Abstract Single-walled carbon nanotube (SWCNT) functionalized with Pd nanoclusters have been shown experimentally to be effective H2S gas sensors. To this end, we have modeled a field-effect transistor with semiconducting SWCNT functionalized with palladium nanoclusters as the channel. Using non-equilibrium Green’s function method combined with density functional theory, we have investigated the effect of Pd nanoclusters on the electrical properties of the device and the sensing ability of the device as an H2S gas sensor at zero bias voltage. We have modeled two devices, one with Au electrodes and the other with SWCNT electrodes to show the effect of Au electrodes on the electrical properties of the device. In order to analyze the reason for the changes in the electrical properties of the device, charge transfer and electrostatic potential of the system are investigated. Results show that in both devices, functionalization with Pd nanoclusters results with the accumulation of charge on the channel while H2S adsorption causes charge depletion in the channel. In all cases, both charge transfer and electrostatic gating are responsible for the changes in the charge-carrier concentration in the channel. Due to significant changes in the electrical
S. Bagherzadeh-Nobari (*) Department of Physics, Safadasht Branch, Islamic Azad University, Tehran, Iran e-mail: [email protected] K. H. Istadeh : R. Kalantarinejad Hamava Innovation Factory, No. 31, Azadi Innovation Factory, Lashgari Highway, Azadi Square, Tehran, Iran
properties of the device after H2S adsorption, detection is possible with high sensitivity. Keywords Quantum transport . Carbon nanotubes . H2S gas sensor . Palladium nanoclusters
Introduction Hydrogen sulfide gas is one of the most hazardous gases in the oil and gas industry that requires to be monitored and detected in low concentrations using real-time detection sensors. Commercial methods used to measure hydrogen sulfide in the air using gas chromatography (GC) or the spectrophotometric method (Shanthi and Balasubramanian 1996) with detection limits of 6.7 ppm and 130 ppb respectively (Chou and World Health Organization 2003). These methods are relatively expensive, burdensome, and not proper for implementing common, consecutive monitoring of hydrogen sulfide in ambient conditions. Conductometric gas sensors based on nanomaterials have gained huge attention due to their distinctive capabilities such as high sensitivity, fast response, and low detection limit (Kolmakov and Moskovits 2004; Yang et al. 2016; Chandran et al. 2017; Bagherzadeh-Nobari et al. 2018; Kalantari-Nejad et al. 2010). In these sensors, nanomaterials act as the transducer in form of the channel in field-effect transistors (FET) or as conducting material betwe
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