Abstract
We present the successful synthesis and characterization of pure and Al: Fe2O3 thin films prepared by spray pyrolysis. The XRD analysis showed a rhomboedric structure with (104) as a preferential orientation for all the layers. AFM and SEM observations exhibited a dense surface with grains uniformly distributed. Optical measurements demonstrated that Al: Fe2O3 (y = 6 and 8 at. %) were highly transparent. In addition, the band gaps values found in the range from 1.98 to 2.17 eV. Hall Effect measurements indicated an n-type conductivity with the lowest resistivity of 2.68 x 102 Ω.cm which reached for the 8 at. % Al: Fe2O3 thin films. Moreover, Al: Fe2O3 thin film based sensor demonstrated a good response to a small amount of ethanol vapor with the adequate response and recovery period at a low operating temperature equal to 250 °C.
•The n-type Fe2O3:Al thin films with low resistivity were obtained by spray method.•All the thin films of Fe2O3:Al have (104) as a preferential orientation.•The electrical properties of Fe2O3:Al are extremely sensitive to the aluminum doping.•Film doped with 8 at. % Al concentration exhibits a fast response to low gas concentration.