ScholarWorks@UNO

Investigating the Surface Modification of In2O3 for enhanced chemical sensing

In2O3 with wide band gap (3.6 eV) and visible light transparency is a very important n-type semiconductive material, which is being extensively investigated in various fields such as solar cells, UV laser, window heaters, flat panel display, gas sensors, etc. The fabrication and testing of In2O3 thin film gas sensors has been subjected to study in previous literature, but the effects of the addition of noble metal catalysts to In2O3 thin films is still a subject under investigation. Our work focuses on comparing the effects of physical and chemical methods of noble metal (Pt) deposition, on In2O3 nanocrystal thin films, on the sensitivity of the fabricated chemical sensors. A one-step synthesis was used to attach the Pt nanoparticles to the In2O3 nanocrystals. The newly synthesized nanocrystals would then be assembled into thin films for subsequent chemical sensor studies. Devices made with bare In2O3, physically modified In2O3, and chemically modified In2O3 were compared under H2S atmostpheres of different concentrations. The noble metal coated nanocrystals were characterized by X-ray diffraction (XRD), transmission electro n microscopy (TEM), and energy dispersive X-ray (EDS). The assembled nanocrystal thin films were characterized by field emission electron microscopy (FESEM). Devices made with bare In2O3, physically modified In2O3, and chemically modified In2O3 were tested and compared under H2S atmospheres of varying concentration.