Selective H₂S sensing characteristics of hydrothermally grown ZnO-nanowires network tailored by ultrathin CuO layers

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• 作者：Niyanta Datta  ; [Author Vitae] ; Niranjan Ramgir  ; [Author Vitae] ; Manmeet Kaur  ; [Author Vitae] ; S. Kailasa Ganapathi  ; [Author Vitae] ; A.K. Debnath  ; [Author Vitae] ; D.K. Aswal ; ^{dkaswal@barc.gov.in} ; ^{dkaswal@yahoo.com}  ; [Author Vitae] ; S.K. Gupta  ; [Author Vitae]
• 关键词：ZnO-nanowires ; CuO ; H2S sensors ; p&ndash ; n junctions ; Photoluminescence
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2012
• 出版时间：20 May, 2012
• 年：2012
• 卷：166-167
• 期：Complete
• 页码：394-401
• 全文大小：1601 K

文摘

Random networks of ZnO nanowires (ZnO-NWs) have been fabricated on the Si/SiO₂ substrates by hydrothermal process using ZnO-nanoparticles as seed. The ZnO-NWs networks have been modified by depositing ultrathin CuO layers (nominal thickness: 10 nm) using thermal evaporation of Cu followed by oxygen annealing at 600 ¡ãC. The results of photoluminescence measurements on ZnO-NWs and CuO:ZnO-NWs networks suggest formation of a p-n junction between p-CuO and n-type ZnO. The gas sensing characteristics of both ZnO-NWs and CuO:ZnO-NWs networks have been investigated. It has been demonstrated that CuO:ZnO-NWs network has selective response toward H₂S with a sensitivity of ?0 (for 10 ppm) at an operating temperature of 200 ¡ãC. A sensing mechanism based on the destruction of p-n junctions due to the formation of metallic CuS (product of chemical reaction between CuO and H₂S) has been proposed.