Design Fabrication and Characterization of Zinc Oxide Schottky Contact Based Thin Film Transistors for Hydrogen Sensing Applications

Abstract

The extending concerns of industrial welfare, chemical regulation and environmental newlinecontamination are stimulating demands for designing and fabrication in gas sensing newlinetechnology to live up to customer expectations. Fast and precise sensors play a pivotal newlinerole in a sustainable society where hydrogen is one of the topmost renewable energy newlinecarriers and fossil fuel candidates. Apart from colorless, odorless, and tasteless nature of newlineH2, its inflammable and explosive nature get exposed when mixed with air because of its newlinelow minimum combustion energy and extensive flammable range. Therefore, accurate newlineand timely leak detection of hydrogen is essentially significant and the need of the hour newlinefor safety reasons in industrial and domestic sectors. Existing optical, acoustic wave, newlineelectrochemical and calorimetric sensors are not sufficient for continuous monitoring due newlineto huge size, high operating temperature (and#8805;300and#8451;), high fabrication cost, design newlinecomplexity, high power dissipation, poor resolution and so on. Existing gas sensors are newlinerequired to be highly sensitive and reproducible for commercial applications. High newlinebandgap energy (3.37 eV at 300 K), high mobility, huge exciton binding energy (60 meV newlineat 300 K), higher thermal conductivity (116 Wmand#8722;1K newlineand#8722;1 newline), superior chemical and thermal newlinestability, near UV emission, strong surface adsorption potential, d newline10 electronic newlineconfiguration and so on ensure ZnO to be a prominent material for hydrogen sensing. newlineTherefore, to obtain high sensing response and in addition to expand the functional newlinedomain of semiconducting oxide based TFTs, there is a need to develop a gas sensor by newlinetaking account of the target gas consuming ability of ZnO and current modulating ability newlineof TFT. Schottky barrier contacts are potentially advantageous as they eliminate thenecessity of any high doping in source/drain area and minimize the effect of parasitic resistances.