Stability and band offsets of nonpolar (112¯0) ZnO on (001) LaAlO3

Wurtzite-perovskite heterostructures consisting of a wide bandgap semiconductor and a high dielectric constant oxide afford the possibility of novel optoelectronic applications. In the present paper, the structural and electronic properties of nonpolar ZnO (112¯0) on LaAlO3 (001) substrates are studied by first-principles calculations. We study the initial adsorption of Zn and oxygen atoms on stoichiometric LaAlO3 (001) surfaces, and find that Zn atoms are more strongly bound to the substrate than oxygen atoms. The surface phase diagrams indicate that Zn atoms may substitute La or Al atoms at the nonstoichiometric LaAlO3 (001) surface. The atomic charges, electronic density of states, and band alignment are systematically analyzed for the optimized ZnO/LaO heterojunction. The band gap is found to be nonzero, and the conduction band offset and the valence band offset are 0.36 eV and 2.61 eV, respectively.