Natural charge spatial separation and quantum confinement of ZnO/GaN-core/shell nanowires

We performed density-functional calculations to investigate the electronic structure of ZnO/GaN-core/shell heterostructured nanowires (NWs) orientating along < 0001 > direction. The built-in electric field arising from the charge redistribution at the {1 (1) over bar 00} interfaces and the band offsets were revealed. ZnO-core/GaN-shell NWs rather than GaN-core/ZnO-shell ones were predicted to exhibit natural charge spatial separation behaviors, which are understandable in terms of an effective mass model. The effects of quantum confinement on the band gaps and band offsets were also discussed. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3504225]