GaN/ZnO superlattice nanowires as photocatalyst for hydrogen generation: A first-principles study on electronic and magnetic properties

In hetero-nanostructures of solid state materials, the reconstruction of charge and spin at the interface can strongly affect the electronic and magnetic properties of the system. The nanomaterials with diverse functions can be achieved by precisely controlling the atomic structure and composition at the interface. Here, we present that the ferromagnetism and bandgap can be controlled by engineering the interfaces in non-magnetic semiconductor (GaN/ZnO) superlattice nanowires. We show that ferromagnetic p-type Zn-N interface can be developed by creating defects at the n-type Ga-O interface because of the defect-induced polar discontinuity. We further show that the bandgaps of the superlattice nanowires are narrowed with the formation of intermediate bands within the bandgaps, resulting in the enhancement of visible-light absorption. These nanostructures may find applications in photocatalyst for water splitting because of the improvement of carrier mobility and light absorption. (C) 2012 Elsevier Ltd. All rights reserved.