Thin Film Gas Sensors Based on Planetary Ball-Milled Zinc Oxide Nanoinks: Effect of Milling Parameters on Sensing Performance
Date
2021
Authors
Sapkota, Raju
Duan, Pengjun
Kumar, Tanay
Venkataraman, Anusha
Papadopoulos, Chris
Journal Title
Journal ISSN
Volume Title
Publisher
applied sciences
Abstract
Planetary ball-milled zinc oxide (ZnO) nanoparticle suspensions (nanoinks) were used to
produce thin film chemiresistive gas sensors that operate at room temperature. By varying milling or
grinding parameters (speed, time, and solvent) different thin film gas sensors with tunable particle
sizes and porosity were fabricated and tested with dry air/oxygen against hydrogen, argon, and
methane target species, in addition to relative humidity, under ambient light conditions. Grinding
speeds of up to 1000 rpm produced particle sizes and RMS thin film roughness below 100 nm, as measured by atomic force and scanning electron microscopy. Raman spectroscopy, photoluminescence,
and X-ray analysis confirmed the purity and structure of the resulting ZnO nanoparticles. Gas sensor
response at room temperature was found to peak for nanoinks milled at 400 rpm and for 30 min in
ethylene glycol and deionized water, which could be correlated to an increased film porosity and
enhanced variation in electron concentration resulting from adsorption/desorption of oxygen ions
on the surfaces of ZnO nanoparticles. Sensor response and dynamic behavior was found to improve
as the temperature was increased, peaking between 100 and 150 C. This work demonstrates the
use of low-cost PBM nanoinks as the active materials for solution-processed thin film gas/humidity
sensors for use in environmental, medical, food packaging, laboratory, and industrial applications.
Description
We thank Sahil Dawka for assisting with sample fabrication; the UBC Bioimaging
Facility for SEM, EDX, and PL spectroscopy; and Western Economic Diversification Canada and A.G Brolo for Raman spectroscopy. T. Kumar was supported by the MITACS Globalink program.
Keywords
ZnO, nanoparticles, planetary ball milling, gas sensor, thin films, nanoink
Citation
Sapkota, R., Duan, P., Kumar, T., Venkataraman, A., & Papadopoulos, C. (2021). Thin film gas sensors based on planetary ball-milled zinc oxide nanoinks: Effect of milling parameters on sensing performance. applied sciences, 11(9676), 1-17. https://doi.org/10.3390/app11209676