Fluorine-doped ZnO thin films deposited by spray pyrolysis technique

¹ Laboratoire de Physique des Matériaux, Faculté des Sciences, Rabat, Morocco
² Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, Madrid, Spain
³ Équipe Batteries Lithium et Dépôts Électrolytiques, Faculté des Sciences, Rabat, Morocco
⁴ Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504 CNRS-UDS, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France

Corresponding author: a-lefdil@fsr.ac.ma

Received: 22 September 2010
Accepted: 5 November 2010
Published online: 28 January 2011

Abstract

Fluorine doped ZnO thin films (FZO) are prepared onto glass substrates at 350 °C by the chemical spray pyrolysis technique. X-ray diffraction spectra show a polycrystalline of ZnO (wurtzite structure) where the amount of fluorine doping affects to preferential orientation (002 plane along c-axis) and does not vary the lattice parameters. Therefore, F introduction in lattice is by the substitution of O^-2 ions by F^-1 ions. Any variation is observed in transmittance and reflectance measurements in 400–2000 nm wavelength range when samples present F dopant; they have transmittance around 80% in the near infrared and visible zones. The FZO films are degenerate and exhibit n-type electrical conductivity. The best resistivity and mobility are 7.6 × 10^-3 Ω cm and 3.77 cm² V^-1 s^-1 respectively. The calculated values of the mean free path are very small compared to the grain sizes calculated using XRD measurements. Therefore, we suggest that ionized impurity and/or neutral impurity scattering are the dominant scattering mechanisms in these films.