Preparation and Characterization of Mixed In2O3 –AgxO Nanostructure Thin Films on porous silicon as NH3 High Gas Sensor

Abstract

Mixed nanostructured thin films composed of In2O3 – AgxO, were synthesized on glass and porous silicon to produce NH3-gas sensor. The films’ structure of the sensor was analyzed by XRD and AFM. The results obtained that polycrystalline nanostructure thin films were prepared. The optical properties indicate that the transmission and the energy gap were decreased with the increase in AgxO ratio. The sensor conductivity changed from n-type for In2O3 up to 10 Vol% AgxO to p-type with mixed oxides. The synthesis gas sensor gives sensitivity toward 40 ppm NH3 gas at different temperatures (50, 100, 150 and 200) ˚C. The maximum sensitivity of mixed films on porous silicon for 15% AgxO ratio is 94.13% with a response time of 11.85 s and a recovery time of 20 s. Porous silicon improves the sensitivity of the prepared sensor by a factor of two with respect to the sensor over the glass. The good sensor properties of In2O3 – AgxO nanostructure mixed oxide at a low temperature indicated as highly efficient NH3 gas sensor.