Semiconducting properties of In2O3 nanoparticle thin films in air and nitrogen

Oil soluble In2O3 nanoparticles were synthesized via the decomposition of indium acetylacetonate in organic solution. In2O3 nanoparticle thin films were prepared by spin-coating the dichloromethane solution of In2O3 on SiO2/Si substrates and annealing at various temperatures. X-ray diffraction and scanning electron microscopy show that the In2O3 nanoparticles are spherical and the quality of thin film surface varies with annealing temperature and time. Field-effect transistor devices of the In2O3 nanoparticles were fabricated and their electronic characteristics were studied in air and nitrogen. The semiconducting properties can be tuned by modifying exposing time of the In2O3-based devices in air. The electron mobility and on–off current ratio have a dramatic change in the starting stage exposed in air, suggesting the device is sensitive to air due to the presence of nanostructures in the In2O3 thin films. The results suggest that the In2O3 thin film device may find applications in gas sensors.