Synthesis and influence of annealing atmosphere on the luminescence properties of ZnGa2O4 nanowires

초록

ZnGa2O4 nanowires were synthesized on Si substrates by the thennal evaporation of a mixture of Zn and GaN powders. The ZnGa2O4 nanowires varied in size from a few tens to a few hundreds of micrometers in diameter, and up to a few hundreds of micrometers in length. The ZnGa2O4 nanowires were found to be a face -centered cubic-strucmred monocrystalline phase. The photoluminescence properties of the ZnGa2O4 nanowires appeared to depend strongly on the annealing atmosphere. The ZnGa2O4 nanowires annealed in a hydrogen atmosphere showed a relatively weak broad visible emission band, ranging from 500 to 700 om. In contrast, the ZnGa2O4 nanowires annealed in an oxygen atmosphere showed a relatively strong near-ultraviolet emission band centered at approximately 380 nm. On the other hand, the ZnGa2O4 nanowires annealed in an argon atmosphere showed a sharp taller ultraviolet emission peak centered at approximately 380 nm as well as a broad green emission band centered at approximately 510 nm. The origins of the enhanced luminescence of the ZnGa2O4 nanowires by annealing in different atmospheres are discussed.