Photoluminescence of ZnO Nanowires with Eu Diffusion Process

摘要

ZnO nanowires with europium (Eu) diffusion process are studied. The ZnO nanowires were grown by chemical vapor deposition on Si substrate with employing Au as catalyst. The diameter of the resulting nanowires was about 200 nm with the length of about 1 urn. To perform the diffusion process, the ZnO nanowires were placed with an Eu shot in a furnace at 900℃. Annealing was performed under vacuum for 1 hr. From photoluminescence spectra excited by a He-Cd laser at room temperature, the green luminescence of the ZnO nanowires with Eu diffusion process observed at about 515 nm is attributed to Eu impurity in ZnO nanowires. Thermal annealing of diffusion process could cause the red shift of near-band-edge emission of ZnO nanowires. From microstructural observations by high-resolution transmission electron microscopy, there exists Eu_2O_3 formed on the surface of ZnO nanowires after Eu diffusion process.