Comparison of ammonia sensing characteristics of individual SnO2 nanowire and SnO2 sol-gel nanocomposite

摘要

SnO2 chemical sensors were fabricated by two different methods. The first one was based on contacting individual nanowires by in situ nanofabricatton in a Focused Ion Beam (FIB) microscope. The second one, the traditional sol-gel method, was based on tin dioxide nanopowder thermal agglomeration. Both types of sensors were capable of detecting air-diluted NH3 to the parts per million level. The responses to this gas were studied at different concentrations and operating temperatures, showing up reproducible characteristics. Their performances were discussed in relation to the accepted mechanisms for NH3 sensing in n-type metal oxides. Investigations were made on device stability, demonstrating that these nanowires have some advantages in comparison with sol-gel sensors.