Self-catalytic VLS growth and optical properties of single-crystalline GeO2 nanowire arrays

Large-scale GeO2 nanowire arrays were successfully synthesized by a simple thermal evaporation method with the mechanism of Self-catalytic Vapor–Liquid–Solid growth. Its morphology and microstructure were determined by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and photoluminescence spectroscopy (PL). The one-dimensional GeO2 nanostructures are extremely sensitive to electron irradiation, and the nanowires were transformed from crystal into amorphous when performing high-resolution transmission electron microscopy (HRTEM). The nanowires have diameters of 100 nm, length of 800 nm and the spherical particles terminating at the tip of the nanowires have diameters of about 500 nm. Two blue emission peaks at 448 nm and 471 nm and a violet emission peak at 411 nm were observed in the room-temperature photoluminescence measurements.