Effect of Al-doped on physical properties of ZnO Thin films grown by spray pyrolysis on SnO₂: F/glass

¹ Laboratoire de Physique de la Matière condensée, Faculté des Sciences de Tunis, Tunis El Manar (2092) Tunisie
² Institut Electronique du Sud, Université de Montpellier II, Place Eugène BATAILLON 34 095 Montpellier cedex 05 France

^a e-mail: ajili.mejda@yahoo.fr

Abstract

Transparent conducting thin films of aluminum-doped zinc oxide (ZnO:Al) have been deposited on SnO₂:F/glass by the chemical spray technique, starting from zinc acetate (CH₃CO₂)₂Zn.2H₂O and aluminum chloride AlCl₃. The effect of changing the aluminum-to-zinc ratio y from 0 to 3 at.%, has been thoroughly investigated. It was found that the optical and electrical properties of Al doped ZnO films improved with the addition of aluminum in the spray solution until y=2%. At this Al doping percentage, the thin layers have a resistivity equal to 4.1 × 10⁻⁴ Ω.cm and a transmittance of about 90 % in the region [600-1000] nm. XRD patterns confirm that the films have polycristalline nature and a wurtzite (hexagonal) structure which characterized with (100), (002) and (101) principal orientations. The undoped films have (002) as the preferred orientation but Al doped ones have (101) as the preferred orientation. Beyond y= 1%, peak intensities decrease considerably.