DFT study for growth of m-plane GaN/ZnO interfaces

Abstract

We have performed density-functional theory calculations to investigate the alignment of gallium (Ga) and nitrogen (N) atoms at m-plane wurtzite GaN/ZnO hetero-interfaces. The potential energy surface (PES) for Ga adatom and N adatom on the clean m-plane ZnO(101̄0) and m-plane ZnO(101̄0) with co-adsorbed Ga and N adatoms are calculated. The most stable alignments in each calculation for PES show us that the hetero-interface structure between GaN and ZnO changes depending on the growth condition. Under the Ga-rich condition, the stable site of N adatom changes because of the self-surfactant effect of the Ga atoms. Under the stoichiometric condition, the stripe structure will be obtained along [0001] direction and the self-surfactant effect of Ga atoms dose not work. Under the N-rich condition, the N adatom forms N2 molecule with the N on the surface and desorb from the surface. We found the condition for growing up an ideal crystal in this hetero-interface. © 2012 The Surface Science Society of Japan.