Structural, optical and electrical properties of In2O3/α-Fe2O3 heterostructure thin films for photocatalytic application

In this study, In2O3/alpha-Fe2O3 heterostructure thin film was prepared on glass substrate using a low-cost and simple spray pyrolysis technique. After successful deposition, the structure and morphology were investigated by X-ray diffraction, scanning electron microscopy, EDX and Raman microscopy. The X-ray diffraction studies confirm the rhombohedral phase of alpha-Fe2O3 and the cubic phase of In2O3 without other impurity peaks, this result also was proved by Raman spectroscopy. The surface morphology of In2O3/alpha-Fe2O3 thin film was determined by using scanning electronic microscopy (SEM), which indicates the formation of a very homogenous surface with a spherical grain randomly disturbed with diverse sizes. Hall effect measurements showed that the conduction of In2O3/alpha-Fe2O3 was n type, and the most electrons are free charge carriers. The resistivity, hall mobility and charge carriers concentration are equal to 5.7 x 10(-4) Omega cm, 5.82 cm(2)/V S and 1.87 x 10(21) cm(-3), respectively. On the other hand, the grain size was equal to 28.2 nm for In2O3 and 30.61 for In2O3/alpha-Fe2O3 thin films. The prepared In2O3/alpha-Fe2O3 thin film was used as a photocatalyst against methylene blue, and this layer demonstrates significantly higher photocatalytic efficiency with degradation rate compared to In2O3 thin layer which may be related to the surface roughness and crystallite size measured by XRD and SEM.