Synthesis of chainlike In2Ge2O7/amorphous GeO2 core/shell nanocables and their luminescence

Novel chainlike In2Ge2O7/amorphous GeO2 core/shell nanocables were successfully synthesized by the simple thermal evaporation method without the presence of catalyst. The growth process of the nanocables is based on vapor-solid (VS) growth mechanism. Its morphology and microstructures were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and photoluminescence spectroscopy. Studies indicate that typical chainlike nanocables consist of single crystalline In2Ge2O7 nanowires (core) with diameter of about 30 nm and amorphous GeO2 chainlike nanostructures (shell). Four emission peaks, namely 401 nm, 448.5 nm, 466.5 nm, and 491 nm, were observed in the room-temperature photoluminescence measurements.