Abstract
Thin films of graphene oxide - titanium dioxide were synthesized by spin coated on glass substrates. Annealing in air from room temperature to 300, 400 and 500 degrees C and at heating rate of about 0.16 degrees C/s affected the film structure, surface morphology and optical properties as studied by X-ray diffractometry, scanning electron microscopy, atomic force microscopy, and ultraviolet-visible transmittance spectroscopy. The film structure changed from amorphous to crystalline state with an increased annealing temperature. A crystalline TiO2 (i.e. anatase) formed at 500 degrees C. At a higher annealing temperature, the surface roughness and grain size of the films increased. The film transmittance reached a maximum of 80% in the visible region and the optical band-gap energy was changed from 3.00 to 3.71 eV. Therefore, these films could be applied in perovskite solar cells for energy harvesting.