Highly conducting zinc oxide thin films achieved without postgrowth annealing

Heavily doped zinc oxide thin films were grown by radio frequency magnetron sputtering. High level of Al doping has been achieved at high growth temperatures (TG), thereby avoiding the need for postgrowth annealing. It is further shown that due to ionized impurity scattering, mobility decreases with increasing TG. Optical transmission spectra show that the bandgap varies from 3.22 to 3.68 eV with increasing Al content due to the combined effect of Burstien-Moss effect and bandgap renormalization. (C) 2010 American Institute of Physics. [doi:10.1063/1.3525575]