Micro gratings written in ZnO: Al thin films using picosecond UV-laser interference patterning

Diffraction micro gratings have been written in ZnO:Al thin films using a picosecond laser operating at 355 nm. Micro gratings of 20 mu m diameter with a period of 860 nm show a groove depth up to 120 nm. The total transmittance of square-centimeter-size grating-textured ZnO:Al films was almost unchanged after grating formation, while the sheet resistance increased moderately. The textured films reached haze values of 9% at 700 nm. This simple texturing method can be applied also to ZnO:Al films that cannot be texture etched. (c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim