Enhancement in the Sensing Efficacy of ZnO-based Ethanol Sensor: Fe-ZnO Film

Authors D.K. Chaudhary1, S.K. Joshi2, S. Thapa3, Y. Yue4, P. Zhu4

1Department of Physics, Amrit Campus, Tribhuvan University, 44600 Kathmandu, Nepal

2Central Department of Chemistry, Tribhuvan University, 44618 Kathmandu, Nepal

3Department of Physics, Concordia College, Moorhead, MN 56562, USA

4Department of Electrical and Computer Science, University of Missouri, Columbia, MO 65211, USA

Е-mail dinesh.chaudhary@ac.tu.edu.np
Issue Volume 16, Year 2024, Number 2
Dates Received 28 December 2023; revised manuscript received 22 April 2024; published online 29 April 2024
Citation D.K. Chaudhary, S.K. Joshi, J. Nano- Electron. Phys. 16 No 2, 02011 (2024)
DOI https://doi.org/10.21272/jnep.16(2).02011
PACS Number(s) 81.20. – n, 78.66. – w, 07.07 – Df
Keywords Fe-ZnO film, Spin-coating (2) , Surface morphology (2) , Ethanol sensing, Gas response.

This study compares the gas sensing performance of the ZnO and 5% Fe-doped ZnO (Fe-ZnO) films synthesized by a spin coating technique. The XRD analysis unveiled the polycrystalline nature of the initially prepared films, showing a decrease in crystallite size from 25.69 ± 0.95 nm for ZnO to 19.49 ± 0.72 nm for Fe-ZnO. Furthermore, the introduction of Fe into ZnO increased the band gap, with values shifting from 3.190 ± 0.105 eV for ZnO to 3.244 ± 0.147 eV for Fe-ZnO and decreased the grain sizes. The reduced grain sizes helped to increase the gas response of the ZnO film. The ethanol vapor sensing experiments performed at a broader temperature range of 100-300 ºC demonstrate that the best gas response of the Fe-ZnO film at 260 ºC is 17.8 ± 0.4 which was nearly 1.5 times greater than that of the ZnO film at the same temperature. Moreover, it's worth noting that the Fe-ZnO thin film exhibited quicker response and recovery in comparison to the ZnO thin film, with response and recovery times of 32 ± 2 and 162 ± 3 s, accordingly, for 40 ppm ethanol exposure. These findings contribute to a deeper understanding of gas sensing mechanisms in both ZnO and Fe-ZnO thin films which hold promise for future developments in gas sensor technology.

List of References