Vapor-phase Synthesis And Photoluminescence Properties Of Quasi-one-dimensional Nano-oxide

Quasi-one-dimensional (Q1D) structures, such as nanowires, nanoneedles, nanobelts and nanotubes, have attracted considerable attention for their potential applications in the development of nanoscale electronics, optoelectronics, magnetoelectronics and sensing devices, due to their superior strength, light, electric, acoustic, magnetic, heat, hydrogen storage and other features. Therefore, they become the focus of researchers currently. Though the research of Q1D nanomaterials already has been got considerable progresses, it still remains a significant challenge to achieve controlled synthesis of Q1D nanomaterials with desired morphologies, components, and structures, which is a foundation and prerequisite for the applications of nanomaterials. Focusing on the research of controlled synthesis of Q1D nanomaterials and relative physical properties, we have done a series of work, and the main contents and conclusion can be summarized as following:1. Synthesis, characterize and photoluminescence properties of SnGeO₃ nanobeltsSnGeO₃ nanobelts were synthesized on a silicon substrate by a simple thermal evaporation method. The structure and morphology of the as-synthesized nanostructure were characterized using scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and photoluminescence spectroscopy. Analyse indicates that the nanobelts have widths of 200-400nm, thickness of 50-70 nm. Because of no nanoparticles were observed at any tips of the nanobelts, the growth process of the nanobelts is based on Vapor-solid (VS) growth mechanism. A strong and broad ultraviolet emission peak at about 406 nm was observed in the room-temperature photoluminescence measurements.2. Synthesis of ZnGa2O4 nanostructures and their luminescenceZnGa2O4 nanostructures were successfully synthesized by simple thermal evaporation of mixed powders of Ga2O₃, ZnO and graphite at 1050℃without using any catalyst. Its microstructures and morphology of the as-synthesized nanostructures were characterized using scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and photoluminescence spectroscopy. The results indicate that the nanostructures were composed of nanoplates. The growth mechanism of the nanoplates is based on Vapor-solid (VS). Photoluminescence properties were also investigated at room temperature. The photoluminescence spectrum reveals the nanostructures have two blue emissions, centering at 430nm and 481nm respectively. The blue band centered 430 nm originates from the Ga–O transition of regular octahedral sites, whereas 481nm can be resulted from oxygen vacancies, gallium vacancies and oxygen-gallium vacancies pairs.3. Synthesis and photoluminescence of aligned SiOx microrod arraysAligned amorphous SiO2 microrods have been synthesized on Si substrate by simple thermal evaporation approach with substrate as source material at 1150℃without using any catalyst via a vapor-solid growth mechanism. The morphologies and microstructures of the products were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and photoluminescence spectroscopy (PL). A broad emission band from 325 to 450 nm is obtained in the photoluminescence (PL) spectrum of these microrods at room temperature. There are three ultraviolet emission peaks centering at 396 nm, 384nm and 373nm, which may be related to various oxygen defects.