Sensing performance of gas sensors fabricated from controllably grown ZnO-based nanorods on seed layers

• Published in: Journal of materials science Vol. 55; no. 21; pp. 8850 - 8860
• Main Authors: Singh, Pragya, Simanjuntak, Firman Mangasa, Wu, Yi-Chu, Kumar, Amit, Zan, Hsiao-Wen, Tseng, Tseung-Yuen
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-07-2020; Springer; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemical Routes to Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Detection; Gas sensors; Grain size; Materials Science; Morphology; Nanorods; Nitric oxide; Polymer Sciences; Room temperature; Sensors; Solid Mechanics; Surface roughness; Zinc oxide
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-020-04659-7

ZnO nanorods (NRs) grown on different ZnO seed layers deposited at various Ar–O
2
ambient conditions, and the morphologies of the seed layers that affect their response to nitric oxide (NO) gas were investigated. The sensing performance of the devices fabricated with the seed layers deposited under an O
2
-rich condition tends to deteriorate. We believe that the surface roughness, grain size, and defect concentration of the seed layer are responsible for this phenomenon. Despite the response to the gas was found to be less dependent on NR length, the gas sensing response is significantly dependent on the oxygen vacancy concentration and the exposure of the NR structure to the NO gas ambient surface. Excellent gas response (57.5% at 1 ppm and 7.1% at 100 ppb of NO gas) was achieved at room temperature—superior to the response presented by other proposed methods. This study not only proposes the potential of ZnO-NRs for high-performance NO gas sensor devices but also offers a simple and low-cost method to optimize the response without using any catalyst and additional treatment.