High temperature stability of postgrowth annealed transparent and conductive ZnO:Al films

High temperature stability of Al-doped ZnO transparent thin films in air has been improved by a combination of optimized growth parameters and postgrowth treatment. Optical transparency was better than 90% for wavelengths ranging from 380 to at least 2500 nm with films that also had resistivities of 2x10(-4) Omega cm. Depending on the growth conditions, film resistivities showed different degrees of increase in resistivity after storing in air at elevated temperatures. Films grown at lower pressures were stable up to 400 degrees C for short exposure times (2 h) and exhibited virtually no change in resistivity at 260 degrees C for over 2500 h. (C) 2008 American Institute of Physics.