کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
745647 | 894426 | 2011 | 7 صفحه PDF | دانلود رایگان |

The conductometric gas sensing characteristics of Cr2O3 thin films – prepared by electron-beam deposition of Cr films on quartz substrate followed by oxygen annealing – have been investigated for a host of gases (CH4, CO, NO2, Cl2, NH3 and H2S) as a function of operating temperature (between 30 and 300 °C) and gas concentration (1–30 ppm). We demonstrate that these films are highly selective to H2S at an operating temperature of 100 °C, while at 220 °C the films become selective to Cl2. This result has been explained on the basis of depletion of chemisorbed oxygen from the surface of films due to temperature and/or interaction with Cl2/H2S, which is supported experimentally by carrying out the work function measurements using Kelvin probe method. The temperature dependent selectivity of Cr2O3 thin films provides a flexibility to use same film for the sensing of Cl2 as well as H2S.
Journal: Sensors and Actuators B: Chemical - Volume 157, Issue 2, 20 October 2011, Pages 466–472