Development of Graphene Based Gas Sensors
type: CreativeWork
description: Graphene is a two dimensional structure of sp2 hybridized carbon atoms arranged in a hexagonal structure. The use of graphene in any application begins with the challenge of producing high quality graphene. The quality, size, and structure of graphene films vary with the desired applications. While reduced graphene flakes are needed for composite materials or conductive paints, planar graphene is needed for high performance electronic devices. The purpose of this research was to study the sensing behavior of graphene. Therefore, a planar sheet of high quality graphene was essential for gas sensing applications. In this study, Chemical Vapor Deposition (CVD) was used to grow large scale graphene on copper foil. Graphene deposition was carried out on a copper foil and transferred to different substrates by wet etching of Cu foil by ferric chloride solution followed by the removal of polymer layer. After the synthesis and transfer of graphene to desired substrate, Raman spectroscopy was used to analyze the quality and number of layers of graphene. Reflectance and Transmittance spectroscopy measurements were also performed to analyze the quality and optical properties of graphene. After the characterization of graphene films, graphene based devices (two-electrode, multiple electrodes (cross-finger type) and top/back gated field effect transistors) were fabricated using photolithography and lift-off processes. A novel technique was developed to grow graphene directly on target substrate with the use of thin film of catalytic metals such as nickel and copper. For the gas sensing behavior, two different approaches (transistor based approach and resistance based approach) were employed to study the adsorption/desorption behavior of ammonia (NH3) on the graphene surfaces. When resistive based graphene sensors were used for the detection of different reducing gases (H2, NH3, CH4) in a practically important operating temperature range, the selectivity of NH3 detection was pron…
abstract: Graphene is a two dimensional structure of sp2 hybridized carbon atoms arranged in a hexagonal structure. The use of graphene in any application begins with the challenge of producing high quality graphene. The quality, size, and structure of graphene films vary with the desired applications. While reduced graphene flakes are needed for composite materials or conductive paints, planar graphene is needed for high performance electronic devices. The purpose of this research was to study the sensing behavior of graphene. Therefore, a planar sheet of high quality graphene was essential for gas sensing applications. In this study, Chemical Vapor Deposition (CVD) was used to grow large scale graphene on copper foil. Graphene deposition was carried out on a copper foil and transferred to different substrates by wet etching of Cu foil by ferric chloride solution followed by the removal of polymer layer. After the synthesis and transfer of graphene to desired substrate, Raman spectroscopy was used to analyze the quality and number of layers of graphene. Reflectance and Transmittance spectroscopy measurements were also performed to analyze the quality and optical properties of graphene. After the characterization of graphene films, graphene based devices (two-electrode, multiple electrodes (cross-finger type) and top/back gated field effect transistors) were fabricated using photolithography and lift-off processes. A novel technique was developed to grow graphene directly on target substrate with the use of thin film of catalytic metals such as nickel and copper. For the gas sensing behavior, two different approaches (transistor based approach and resistance based approach) were employed to study the adsorption/desorption behavior of ammonia (NH3) on the graphene surfaces. When resistive based graphene sensors were used for the detection of different reducing gases (H2, NH3, CH4) in a practically important operating temperature range, the selectivity of NH3 detection was pron…
author: Gautam, Madhav
language: English
keywords: Engineering, Mechanical Engineering, Materials Science, Electrical Engineering, Graphene, Synthesis, Gas Sensors, Field effect transistors, GFET devices, Ammonia sensing, Organic vapor sensing, Gas sensing mechanism
date published: 2013-09-05
date modified: 2026-07-24T03:37:16Z
provider: OhioLINK
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Toledo