Zn3N2 nanowires: growth, properties and oxidation

Zinc nitride (Zn3N2) nanowires (NWs) with diameters of 50 to 100 nm and a cubic crystal structure have been grown on 1 nm Au/Al2O3 via the reaction of Zn with NH3 including H-2 between 500A degrees C and 600A degrees C. These exhibited an optical band gap of a parts per thousand 3.2 eV, estimated from steady state absorption-transmission spectroscopy. We compared this with the case of ZnO NWs and discussed the surface oxidation of Zn3N2 NWs which is important and is expected to lead to the formation of a Zn3N2/ZnO core-shell NW, the energy band diagram of which was calculated via the self-consistent solution of the Poisson-Schrodinger equations within the effective mass approximation by taking into account a fundamental energy band gap of 1.2 eV. In contrast, only highly oriented Zn3N2 layers with a cubic crystal structure and an optical band gap of a parts per thousand 2.9 eV were obtained on Au/Si(001) using the same growth conditions.