NOx sensing properties of In2O3 nanoparticles prepared by metal organic chemical vapor deposition

In2O3 nanoparticles were deposited by low-temperature metal organic chemical vapor deposition. The response of 10-nm thick In2O3 particle containing layers to NOx and O2 gases is investigated. The lowest detectable NOx concentration is ∼200 ppb and the sensor performance is strongly dependent on the gas partial pressure as well as on the operating temperature. The sensor response towards 200 ppm of NOx is found to be above 104. Furthermore, the cross-sensitivity against O2 is very low, demonstrating that the In2O3 nanoparticles are very suitable for the selective NOx detection.