Surface Topography and Sensitivity Properties of SnO₂/Fe₂O₃ Nanocomposite Thin Films

In this study, nanocomposite SnO₂/Fe₂O₃ films have been successfully deposited on glass substrates by chemical spray pyrolysis (CSP) technique at substrate temperature of (400 °C), and the thickness of the prepared films were about (300 nm), and different composite concentration (20, 30, 40, 50 and 100%). The surface topography and sensitivity properties of these films have been investigated using Atomic Force Microscopy (AFM) and sensitivity to NO₂ gas in air ambient has been measured in gas sensing system. AFM results showed homogenous and smooth SnO₂/Fe₂O₃ nanocomposite films. The average grain size, average roughness (RS) and root mean square (RMS) roughness, ten point height, for SnO₂/Fe₂O₃ nanocomposite films were estimated from AFM. The sensitivity of nanocomposite SnO₂/Fe₂O₃ films to NO₂ gas in air ambient has been measured in gas sensing system. All samples were tested at different composite concentrations, and bias voltage (6 volt). The maximum sensitivity of the SnO₂/Fe₂O₃ nanocomposite thin film to NO₂ gas is found to be 90.84% at 250 °C for SnO₂ pure thin film. The lesser response and recovery time at this point were coming from 60%SnO₂/40%Fe₂O₃ at time 13 sec for response time and 23 sec for recovery time comparing to other samples.