Event Details
Thin Film Gas Sensors Based on Zinc Oxide Nanoinks
Presenter: Pengjun Duan
Supervisor:
Date: Wed, December 15, 2021
Time: 14:00:00 - 15:00:00
Place: via Zoom - please see link below
ABSTRACT
ZOOM MEETING INFORMATION:
URL: https://uvic.zoom.us/j/83628261102?pwd=eG13bjFONzY4bnRzRFNWSStncVNHQT09
Meeting ID: 836 2826 1102
Password: 359619
SPEAKER: Pengjun Duan
SUPERVISOR: Dr. Christo Papadopoulos
TITLE: Thin Film Gas Sensors Based on Zinc Oxide Nanoinks
ABSTRACT: Planetary ball milling (PBM) is a high-energy ball milling technology that was used to fabricate zinc oxide (ZnO) nanoinks by nano grinding, followed by thin film chemiresistive gas sensors fabrication via doctor blading method, which operates at room temperature. In order to create the different thin film gas sensor samples (with different particle sizes and porosity), the ZnO nanoinks were prepared by changing the grinding parameters, such as grinding time, grinding speed and solvents (ethylene glycol (EG) and deionized water (DI water)). To study the gas sensing performance, we tested these samples by using dry air/oxygen against hydrogen, argon and methane target gases, in addition to different temperatures and different relative humidity, under ambient light conditions. In this report, the particle size and RMS film roughness were measured by atomic force and scanning electron microscopy; the purity and structure of ZnO nanoparticles are confirmed by Raman spectroscopy, photoluminescence, and x-ray analysis. At room temperature, the gas sensor response of thin film sample reaches the peak for nanoinks milled at 400 rpm and 30 min. This is probably related to the increase of film porosity and the enhancement of electron concentration change, caused by oxygen ion adsorption/desorption on the surface of zinc oxide nanoparticles. In addition, research also indicates that the sensor response and dynamic behaviour improves with temperature increasing, reaching a peak value between 100 – 150 ºC. Our study proves the application of low-cost PBM nanoink as an active material for solvent treated thin film gas/humidity sensors, and provides some suggestions to improve gas sensors in future study, such as measuring system, ZnO nanomaterials with different morphologies, and doping.