A surface acoustic wave H₂S gas sensor employing nanocrystalline SnO₂ thin film

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• 作者：Wei Luo^a ; ^bAuthor Vitae ; Qiuyun Fu^a ; ^{fuqy@mail.hust.edu.cn}Author Vitae ; Dongxiang Zhou^aAuthor Vitae ; Jianfeng Deng^aAuthor Vitae ; Huan Liu^aAuthor Vitae ; Guoping Yan^bAuthor Vitae
• 关键词：Surface acoustic wave sensor ; Tin oxide films ; Hydrogen sulfide sensor ; Nanocrystalline thin film
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：176
• 期：Complete
• 页码：746-752
• 全文大小：1638 K

文摘

A surface acoustic wave (SAW) H₂S gas sensor with high sensitivity and good recovery characteristics was presented. SnO₂ films with an average grain size of 25 nm were deposited as the sensitive film at the surface of the SAW devices using an aqueous sol-gel technique. The sensitivity toward H₂S gas was increased by optimizing parameters including film thickness and operating temperature. The maximal response (center frequency change) toward 68.5 ppm of H₂S was 112.232 kHz when the sensor was operated at 120 ¡ãC with SnO₂ film thickness of 275 nm. The frequency response of the SAW sensor showed good selectivity and a linear relation to H₂S gas with different concentrations. We demonstrated that the dominant sensing mechanism of this SAW sensor is the acoustoelectric effect arising from the electrical conductivity change of the SnO₂ film. Further analysis of the optimum parameters and the good recovery characteristics were conducted based on the acoustoelectric effect.