Highly sensitive hydrogen safety sensor based on Cr incorporated ZnO nano-whiskers array fabricated on ITO substrate

• Published in: Sensors and actuators. B, Chemical Vol. 237; pp. 912 - 923
• Main Authors: Renitta, A., Vijayalakshmi, K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2016
• Subjects: Cr-ZnO thin films; Crystal structure; Dopants; H2 sensor; Hydrogen; ITO substrate; Nano-whiskers; Nanostructure; Optical properties; SEM; Sensors; Spray pyrolysis; Substrates; Zinc oxide; Nano-whiskers; H2 sensor; ITO substrate; SEM; Spray pyrolysis; Cr-ZnO thin films
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2016.07.017

[Display omitted] This study explores the fabrication of a novel nano-whiskers array of Cr incorporated ZnO on ITO substrate exhibiting high sensing response to hydrogen (H2) gas at room temperature. The Cr-ZnO films prepared by a novel spray deposition route were characterized for its structure, composition, optical and luminescence properties. The crystal structure revealed that the Cr dopants were well integrated into the ZnO wurtzite lattice. All the films exhibit single crystalline nature with high c-axis orientation. Cr dopant played an essential role in the enhancement of the crystalline quality and optical band gap energy of the films. The PL spectra revealed strong and broad violet-blue emission from Cr-ZnO nano-whiskers with increasing Cr content. SE-micrograph of the films show the remarkable change in morphology from nanotubes to nanowires with increase in Cr dopant concentration. The Cr dopant exhibit significant effect in fine tuning the structure of nanoparticles and size of the nano-whiskers. The H2 gas sensing characteristics of Cr-ZnO nano-whiskers was investigated. Amongst all sensors fabricated with different Cr dopant concentration, the 4 at.% Cr incorporated ZnO sensor exhibited fast response and recovery towards low concentration of H2 at room temperature.