Role of substrate temperature on the ammonia gas sensing performance of Mg-doped ZnO thin films deposited by spray pyrolysis technique: application in breath analysis devices

• Published in: Applied physics. A, Materials science & processing Vol. 124; no. 9; pp. 1 - 10
• Main Authors: Goudarzi, S., Khojier, K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2018; Springer Nature B.V
• Subjects: Ammonia; Applied physics; Atomic force microscopy; Characterization and Evaluation of Materials; Chemical composition; Condensed Matter Physics; Crystal structure; Crystallography; Detection; Field emission microscopy; Gas sensors; Glass substrates; Humidity; Machines; Magnesium; Manufacturing; Materials science; Microscopy; Morphology; Nanotechnology; Optical and Electronic Materials; Organic chemistry; Physics; Physics and Astronomy; Processes; Relative humidity; Reliability analysis; Reproducibility; Scanning electron microscopy; Selectivity; Sensitivity analysis; Spray pyrolysis; Surfaces and Interfaces; Thin Films; X-ray diffraction; Zinc oxide
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-018-2020-8

This research investigates the role of substrate temperature on crystallographic structure, surface morphology, and subsequently ammonia gas sensing performance of Mg-doped ZnO thin films as a breath analysis device. The Mg-doped ZnO thin films were deposited by spray pyrolysis technique on glass substrates at different temperatures (125 °C, 250 °C, 375 °C, and 500 °C). Crystallographic structure, surface morphology, and chemical composition of the samples were characterized using X-ray diffraction (XRD) method, atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM). Ammonia sensing characteristics of the samples were studied at room temperature and relative humidity of 80%. The results revealed that the Mg-doped ZnO thin film deposited at 375 °C showed the most sensitivity to ammonia gas. Selectivity and reliability (reproducibility as well as short and long time stability) of the mentioned sample were also investigated. The results showed that the Mg-doped ZnO thin film deposited at 375 °C can be a good candidate to sense the ammonia as a breath analysis device due to its good sensitivity, selectivity, and reliability at high-relative humidity.