Domain boundaries and growth manner of a-plane ZnO film on symmetric (001)LaAlO3 substrate

Non-polar a-plane ZnO film grown on (00 1)LaAlO3 (LAO) substrate has been systematically characterized by employing transmission electron microscope. On (00 1)LAO substrate, a-plane ZnO film comprises two main orientation types of domains perpendicular to each other. In one orientation type of a-plane ZnO domains, stacking mismatch boundary (SMB) and inversion domain boundary (IDB) form in the coalescence of two domain islands parallel to each other. SMB is composed of m-and r-planes. IDB extends along m-plane. The in-plane growth of a-plane ZnO domains extends along the direction with-45 degrees -rotation to [0 0 01]ZnO. The bound-aries of two perpendicular a-plane ZnO domains consist of 45 degrees -boundaries and r-plane twin boundaries. The profile of a-plane ZnO domain appears as L-shape.