Abstract

Effect of substrate temperature and concentration on spray deposited zinc oxide thin films

Author(s): R.T.Sapkal, S.S.Shinde, A.R.Babar, K.Y.Rajpure, P.S.Patil, C.H.Bhosale

Zinc Oxide (ZnO) thin films have been deposited onto glass substrates by economical spray pyrolysis at different substrate temperatures and concentrations of Zinc acetate used as precursor under atmospheric pressure. The filmswere characterized byXRD, optical transmittance and SEMtechniques. All the films are polycrystalline with hexagonal wurtzite structure, with caxis growth (002) perpendicular to substrate surface. At the substrate temperature of 4000C and solution concentrationof 0.2M, ZnOthin films exhibited highest crystallinity. The grain size, Zn – O bond length, dislocation density and stress of the films changes from72.26 nmto 105.33 nm., 1.9699 A0 to 1.9725A0, 1.863 x 10-4 (nm)-2 to 0.9032 x 10-4 (nm)-2and - 0.48798Gpa to 55.066 Gpa respectively. Morphological study showed surface microrods are obtained at lower concentration (0.1M). Length and diameter of surface microrods were found in the range from 1µm to 8 µm and 0.1 µm to 0.9 µm respectively. Optical band gap was found to be in the range 2.92 eV to 3.24 eV. The average transmission of the films is about 85%in the visible region.