Influence of SiO2 passivation and annealing on the luminescence properties of GeO2 nanowires

초록

GeO2-core/SiO2-shell nanowires were synthesized on (100) Si substrates by thermnal evaporation sputter-deposition of SiO2. X-ray diffraction, scanning electron microscopy and transmission electron microscopy (TEM) analyses showed that the mean diameter and lengths of the core-shell nanowires were approximately 100 nm and from a few tens to a few hundred of micrometer respectively. hundres of micrometers, respectively. The photoluminescence measurements showed that pure GeO2 nanowires had a violet emission band centered at approximately 430 nm. Our results show that the photoluminescence emission of GeO2 nanowires can be significantly enhaned in intensity by SiO2 coating followed by thennal annealing in a reducing atmosphere. We also revealed the origin of the PL enhancement with the aid of energy dispersive X-ray spectroscopy analyses.