Highly textured zinc oxide films were produced on basal plane sapphire substrates by chemical solution deposition. Films with oriented growth were achieved by spin coating a 0.75 M precursor solution of zinc acetate dihydrate and ethanolamine in 2-methoxyethanol, heated at 300 deg C/10 min, then at 500 deg C/5 h, and finally at 850 deg C/12 h. Films were characterized with x-ray diffraction (XRD) and scanning and transmission electron microscopy. The films exhibited only the (0002) ZnO line in XRD diagrams, proving a very well-developed out-of-plane texture. At temperatures above 700 deg C the ZnAl_2O_4 spinel was observed, which formed as a reaction layer between sapphire and ZnO. Few specimens produced both in-plane and out-of-plane oriented growth of ZnO on basal plane sapphire. It was hypothesized that the substrate miscut, uncontrolled for the current experiments, could be the cause of the infrequent growth of epitaxial films.
展开▼
