Chemical sensing investigations on Zn-In₂O₃ nanowires

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• 作者：N ; an Singh ; Andrea Ponzoni ; Elisabetta Comini ; Pooi See Lee
• 关键词：Indium oxide ; Zn-doping ; Nanowires ; Gas sensor ; Oxygen vacancies
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2012
• 出版时间：August-September, 2012
• 年：2012
• 卷：171-172
• 期：Complete
• 页码：244-248
• 全文大小：758 K

文摘

This work illustrates the sensing behavior of Zn-doped and undoped In₂O₃ nanowires toward pollutant gases. An enhanced sensor response to reducing gases (e.g. H₂, CO and ethanol) from indium zinc oxide (IZO) nanowires in comparison to In₂O₃ nanowires is obtained. Zn-doping increases the oxygen vacancies which enhance the oxygen ion adsorption on the nanowire surface. These adsorbed oxygen ions enhance the sensor responses for CO (from 4.5 to 21.5 for 400 ppm), H₂ (from 4.7 to 32.5 for 4000 ppm) and ethanol (from 3.5 to 60 for 100 ppm). On the other hand, the sensor response for NO₂ reduces (from 17.5 to 6.5 for 1 ppm NO₂) after Zn-doping. Opposing temperature dependent sensor response from IZO nanowires toward NO₂ is observed at higher temperature (above 300 ¡ãC). This is attributed to the downshift in the Fermi level of IZO due to dissociative NO₂ interaction at higher working temperatures which produces oxygen ions that diffuse into the nanowire.