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

• Published in: Thin solid films 2014-10, Vol.568, p.25-30
• Main Authors: Sommer, Nicolas, Götzendörfer, Stefan, Köhler, Florian, Ziegner, Mirko, Hüpkes, Jürgen
• Format: Article
• Language: English
• Subjects: Aluminum; Aluminum-doped zinc oxide; Charge carriers; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Glass; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Morphology; Physics; Rough substrates; Silicon thin film solar cells; Sputtering; Structure and morphology; thickness; Surface layer; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Texture; Texture-etched glass; Theory and models of film growth; Thin film structure and morphology; Transparent conducting oxide; Zinc oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2014.07.045

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. •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