Controllable synthesis of Sn:ZnO/SnO2 nanorods: pH-dependent growth for an ethanol gas sensor

• Published in: Journal of Materials Science: Materials in Electronics
• Main Author: Mohamed R.; Mamat M.H.; Malek M.F.; Ismail A.S.; Rafaie H.A.; Rusop M.
• Format: Article
• Language: English
• Published: Springer 2020
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088970697&doi=10.1007%2fs10854-020-04103-1&partnerID=40&md5=6d531c13edaabbfe312a4e8da9c88fe0

Tin-doped zinc oxide/tin oxide nanorod (Sn:ZnO/SnO2 NR) films were successfully synthesized using a solution immersion method by manipulating the pH concentration of the solutions to fabricate an ethanol gas sensor. Sn:ZnO/SnO2 NR films were prepared at constant Sn:ZnO solution pH (5.5), while the pH of the SnO2 solutions was varied between 4.5 and 6.5. In this study, the structural, morphological, and optical properties of Sn:ZnO/SnO2 NR films were investigated. The diameter and thickness of Sn:ZnO/SnO2 NR films were found to increase with the SnO2 pH. Interestingly, the Sn:ZnO/SnO2 NR sample that was prepared at SnO2 solution pH 5.5 showed the highest relative peak intensity along the c-axis plane orientation, which enhanced the sensor performance due to the shorter carrier pathway. In addition, this sample indicated a higher level of surface donor-related defects, which are favorable for sensing device performance. The samples were exposed to ethanol gas to measure their gas-sensing properties. Sn:ZnO/SnO2 NR films prepared at SnO2 solution pH 5.5 showed the highest sensing performance with short response/recovery times. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.