CdS/ZnO Core/Shell Nanowire‐Built Films for Enhanced Photodetecting and Optoelectronic Gas‐Sensing Applications. Issue 8 (20th May 2014)

• Record Type: Journal Article
• Authors: Yang, Zheng; Guo, Linjuan; Zu, Baiyi; Guo, Yanan; Xu, Tao; Dou, Xincun
• Is Part Of: Advanced optical materials. Volume 2:Issue 8(2014:Aug.)
• Page Start: 738
• Page End: 745
• Publication Date: 2014-05-20
• Subjects: Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201400086
• Languages: English
• ISSNs: 2195-1071

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Uniform CdS/ZnO core/shell nanowires are hydrothermally synthesized using a two‐step process and assembled into a photodetector and a NO₂ optoelectronic sensor for the first time. The corresponding photodetector exhibits a fast, reversible, and stable optoelectronic response with a rise time of ∼26 ms, a decay time of ∼2.1 ms and a stability of over 5 months. The remarkable photosensitivity and fast photoresponse are attributed to the formation of a heterojunction structure between CdS and ZnO, which greatly inhibits the recombination of photoinduced electrons and holes. The CdS/ZnO core/shell nanowires also show an excellent visible‐light‐activated gas sensing performance towards ppb‐level NO₂ at room temperature. The responses range from 6.7% to 337% toward NO₂ concentrations of 5 to 1000 ppb. It is found that the sensitivity of the NO₂ sensor is dependent on the illuminated light intensity with a maximum value at 0.68 mW/cm². The sensing mechanisms of the CdS/ZnO nanowires under visible‐light irradiation and the influence of light intensity are also discussed. The present CdS/ZnO core/shell nanowire not only benefits the fabrication of efficient photodetectors, but also makes the instant, optically controlled sensing of ppb‐level NO₂ gas possible.</p> </abstract>