Influence of deposition conditions and substrate morphology on the electrical properties of sputtered ZnO:Al grown on texture-etched glass

• Growth of ZnO:Al on various texture-etched glass substrates
• Reduced influence of growth disturbances using optimized sputtering conditions
• Higher ZnO:Al charge carrier mobility on U-shaped than on V-shaped textures

The focus of this work is the growth of aluminum-doped zinc oxide (ZnO:Al) on texture-etched glass substrates. We investigated the influence of sputter parameters, pressure and temperature on the charge carrier mobility of ZnO:Al films grown on different substrate textures. An optimized sputtering process was developed which led to charge carrier mobilities on textured substrates that are close to those on flat substrates. Based on X-ray diffraction measurements, we qualitatively explain the effect of different sputtering conditions. Furthermore, the ZnO:Al charge carrier mobility was related to the substrate morphology. ZnO:Al films on U-shaped surface morphologies showed significantly higher charge carrier mobilities than those on V-shaped structures. ZnO:Al damp heat stability and etching behavior provided evidence that the number of ZnO:Al growth disturbances on textured substrates can be reduced by adequate substrate morphology and sputtering conditions.