Optical and Structural Properties of ZnO Thin Films Fabricated by Sol-Gel Method

Abstract

Highly oriented and transparent ZnO thin films have been fabricated on ultrasonically cleaned quartz substrates by the sol-gel technique. X-ray diffraction, UV-VIS, FTIR, photoluminescence and SEM are used to characterize ZnO thin films. X-ray diffraction study show that all the films prepared in this work have hexagonal wurtzite structure, with lattice constants a = b = 3.260 Å, c = 5.214 Å. The optical band gap energy of the thin films is found to be direct allowed transition ~3.24 eV. The FTIR spectrum of the film has the characteristics ZnO absorption band at 482 cm?1. The photoluminescence spectrum of the samples has an UV emission peak centred at 383 nm with broad band visible emission centred in the range of 500 - 600 nm.