Effect of temperature on morphologies and optical study of ZnO thin films deposited by aerosol assisted chemical vapor deposition technique

Abstract

ZnO thin films were deposited on glass substrates by an aerosol assisted chemical vapor deposition method using Zn(II) semicarbazone complexes, ZnCl2(LH)2, (where LH = semicarbazones of cinnamaldehyde, 4-flouroacetophenone, benzaldehyde and 4-chlorobenzaldehyde) as precursors. X-ray diffraction patterns of as-deposited thin films show the formation of hexagonal ZnO (ICDD: 79-2205) at all the deposition temperatures, i.e. 350 °C, 400 °C and 450 °C. The UV–visible spectra show that the thin films are transparent in the visible range. The presence of the high intensity phonon mode at 438 cm−1 in the Raman spectra indicates the wurtzite phase of the ZnO thin films. Scanning electron microscopy images reveal the formation of different morphologies, hexagonal plates, nearly spherical particles and tetrapods at different temperatures. The roughnesses of the thin films were determined using atomic force microscopy.