Visible-light activated ZnO/CdSe heterostructure-based gas sensors with low operating temperature

• Published in: Applied surface science 2016-01, Vol.360, p.652-657
• Main Authors: Wu, Bin, Lin, Zhangqing, Sheng, Minqi, Hou, Songyan, Xu, Jifang
• Format: Article
• Language: English
• Subjects: Activated; Cadmium selenides; Gas sensor; Gas sensors; Heterostructures; Intermetallics; Light (illumination); Low operating temperature; Operating temperature; Visible light illumination; Zinc oxide; ZnO/CdSe
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.11.037

⿢The ZnO/CdSe based sensors worked in low temperature.⿢The optimum operating temperature of 160°C is 100°C lower than that of ZnO.⿢The sensitivity was 20-fold higher in dark than that of ZnO.⿢The sensitivity was 3-fold higher under illumination than that of ZnO. Three-dimensional ZnO/CdSe heterostructure (ZnO/CdSe HS) was fabricated with large scale and its gas-sensing application with low operating temperature was explored. Combining cost-effective chemical vapor deposition with solution growth methods, ZnO nanorods were grown on the surface of CdSe nanoribbons. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy were employed to confirm the formation of ZnO/CdSe HS. The ZnO/CdSe HSs were fabricated as gas sensors in the detection of ethanol at the optimum operating temperature of 160°C. Compared with ZnO-based gas sensors, the optimum operating temperature of the ZnO/CdSe HS-based sensor was approximately 100°C lower, while the sensitivity was 20-fold higher in the dark and 3-fold higher under visible light illumination condition. The enhancement of sensing properties was attributed to the advanced heterostructure and visible light activated CdSe.