The effect of growth temperature on physical properties of heavily doped ZnO:Al films

Abstract

Abstract Heavily‐doped ZnO:Al films have been deposited on high temperature stable glass substrates using radio‐frequency (RF) magnetron sputtering. The effect of growth temperature on physical properties of the films has been investigated. The microstructure evolved a columnar structure into a granular one with the increase in growth temperature and then a typical honeycomb‐type microstructure representing huge grain formation indicating high densification. All Al‐doped ZnO films exhibited high optical transparency and the absorption edge shifted to the short wavelength (blue‐shift) as the growth temperature increased. The dense microstructure with a high crystallographic quality and large grains evolved at 500 °C enabled us to obtain 2.28 × 10 –3 Ω cm and high visible transmittance over 90% even if the ZnO film was doped with an Al content of approximately 5.5 at%. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)