Abstract
V sub(2)O sub(5) NRs were prepared by a spray pyrolysis onto heated glass substrates at various substrate temperatures. X-ray diffraction (XRD) results indicated that the films obtained at T sub( )s= 250 degree C have low peak intensities. However, the degree of crystallinity increases when the temperature was increases to T sub( )s= 350 degree C, and films have orthorhombic structures with preferential orientations along the (110) direction. FESEM observations showed that rod-like shaped morphology is in the 100-150 nm diameter range and in the 1-3 mu m length range. Optical transmittance in the visible range increases to reach a maximum value of approximately 80%, at a substrate temperature of T sub( )s= 350 degree C. The optical band gap is determined when there is a decline in optical absorbance spectra at an increasing substrate temperature; 2.46 eV in the amorphous phase, at 250 degree C to 2.02 eV in the nanocrystalline phase, at 350 degree C. Photoluminescence spectra revealed two main broad peaks at around 516-533 nm with high intensity.