Tin oxide nanobelts electrical and sensing properties

Semiconducting oxides nanobelts of tin oxide have been obtained by vapour phase deposition, using SnO as source material. In this work, we present the results obtained using tin oxide nanobelts as conductometric gas sensors. Electrical characterization showed that the nanobelts were sensitive to oxygen and environmental polluting species, like CO and NO, as well as ethanol for breath analyzers and food control applications. The sensor response, defined as the relative variation in conductance or resistance due to the introduction of the gas, is 200% for 30 ppm of CO at 350 degrees C, 900% for 200 ppb NO2 at 300 degrees C, and 2500% for 10 ppm of ethanol at 350 degrees C. It has been studied the variation of the response as a function of the density of the nanobelts. The results demonstrate the potential of fabricating nanosize sensors using the integrity of a single nanobelt with sensitivity at the level of a few ppb and the necessity to control nanobelts density to optimize the sensing performances. (c) 2005 Elsevier B.V. All rights reserved.