Effect of Flash Lamp and Furnace Annealing on the Electrical and Optical Properties of Ti-Al-Codoped ZnO Films...

Aluminum-doped zinc oxide (AZO) is one of the most commonly used transparent conductive oxides because of its low resistivity and high transmittance. AZO is an excellent candidate for transparent electronic devices, photovoltaics, and thin-film technologies. However, the resistivity and ultraviolet-visible (UV-vis) transmission of AZO are still significantly inferior to those of indium tin oxide (ITO). Two things are needed for the practical application of AZO: low resistance and low production costs. One method of reducing the resistance of the layer is codoping AZO with titanium, while lower production costs can be achieved by using more efficient technological processes. In this work, we investigated the influence of titanium codoping and millisecond-range flash lamp annealing (FLA) on the structural and optoelectronic properties of Ti-Al-doped ZnO (TAZO) thin films fabricated by magnetron sputter deposition. Ti was codeposited into the AZO films by placing Ti pellets on top of the AZO target during magnetron sputtering. Postdeposition annealing was performed using either conventional furnace annealing (FA) for 30 min or FLA for 23 ms. Our results show that thermal treatment by millisecond-range FLA improves the electrical conductivity of TAZO by a factor of approximately 100 while maintaining an average transmittance of over 80%. At the same time, FLA requires much less energy than conventional heating, which makes it more economically efficient. By directly comparing FA and optimized FLA, we demonstrate that FLA-treated samples achieve similar or superior crystallinity and a 1 order of magnitude lower sheet resistance while preserving comparable optical transmittance. These results demonstrate that the combination of FLA and Ti codoping significantly enhances the performance of TAZO thin films, making them promising candidates for transparent electrode applications in optoelectronic devices.