Two novel methods for evaluating the performance of OTFT gas sensors

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• 作者：Tao XieAuthor Vitae ; Guangzhong Xie ; ^{gzxie@uestc.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Hongfei DuAuthor Vitae ; Yuanjie SuAuthor Vitae ; Zongbiao YeAuthor Vitae ; Yuyan ChenAuthor Vitae ; Yadong Jiang ^{jiangyd@uestc.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：P3HT ; ZnO-nanorods ; Composite film ; OTFT ; Gas sensor
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：230
• 期：Complete
• 页码：176-183
• 全文大小：2918 K

文摘

Two methods were proposed to evaluate the performance of organic thin film transistor (OTFT) gas sensors. A back-gated OTFT gas sensor with poly(3-hexylthiophene) (P3HT)/zinc oxide (ZnO) nanorods composite films as the active layer and gas sensing layers were prepared for nitrogen dioxide (NO₂) detection. The electrical parameters of OTFTs based on pure P3HT film and P3HT/ZnO-nanorods composite films were calculated and analyzed. The response characteristics of gas sensor to NO₂ were studied. It can be found that the response of OTFT gas sensor was inaccurate according to conventional definition. The effects of humidity and temperature on the response of sensors were evaluated. However, OTFT, as a multiparameter sensor, can provide more information to evaluate the gas sensing properties. The variation of V_th of OTFT gas sensor was associated with the content of ZnO-nanorods and the concentration of NO₂. The variation mechanism of V_th was analyzed as well. The results indicated the variation of V_th as the response of sensor was reliable. The variation of V_th was attributed to the impact introduced by NO₂ molecules on the charge carrier motion. In addition, the slope of fitting line (ΔI versus log t) was proposed as a new method to evaluate the gas properties of OTFT sensors. The calculated results illustrated that the sensitivity can be magnified compared to the variation of V_th and increased 40.2% due to appropriate amount of ZnO-nanorods doping.