The interfacial relationship and the microstructure of non-polar (11•0) ZnO films epitaxially grown on (1¯1•2) R-plane sapphire by molecular beam epitaxy were investigated by transmission electron microscopy. The already-reported epitaxial relationships [11¯•0]ZnO||[11•0]sapphire and <00•1>ZnO||[1¯1•1]sapphire were confirmed, and the orientation of the Zn–O (cation-anion) bond along [00•1]ZnO was determined in films as being uniquely defined with respect to a reference surface Al–O bond on the sapphire substrate. The microstructure of the films was dominated by the presence of I1 basal stacking faults [density = (1–2) x 105/cm] and related partial dislocations [density = (4–7) x 1010/cm2]. It was shown that I1 basal stacking faults corresponded to dissociated perfect dislocations, either c or a+c type.

Interfacial Structure and Defect Analysis of Nonpolar ZnO Films Grown on R-Plane Sapphire by Molecular Beam Epitaxy. Vennéguès, P., Chauveau, J.M., Korytov, M., Deparis, C., Zuniga-Perez, J., Morhain, C.: Journal of Applied Physics, 2008, 103[8], 083525