Intense ultraviolet emission from needle-like WO3 nanostructures synthesized by noncatalytic thermal evaporation
نویسندگان
چکیده
Photoluminescence measurements showed that needle-like tungsten oxide nanostructures synthesized at 590°C to 750°C by the thermal evaporation of WO3 nanopowders without the use of a catalyst had an intense near-ultraviolet (NUV) emission band that was different from that of the tungsten oxide nanostructures obtained in other temperature ranges. The intense NUV emission might be due to the localized states associated with oxygen vacancies and surface states.
منابع مشابه
Hierarchical oxide nanostructures
A variety of hierarchical oxide nanostructures, including ZnO nanonails on nanowires/nanobelts, ZnO nanorods on nanobelts, comb-like ZnO nanostructures, hierarchical MgO nanowires, etc., have been synthesized by thermal vapor evaporation and condensation. Observation of these nanostructures demonstrates the diversity of the geometry of these oxides in the nanoscale range. These nanostructures m...
متن کاملSynthesis of Novel Double-Layer Nanostructures of SiC–WOxby a Two Step Thermal Evaporation Process
A novel double-layer nanostructure of silicon carbide and tungsten oxide is synthesized by a two-step thermal evaporation process using NiO as the catalyst. First, SiC nanowires are grown on Si substrate and then high density W(18)O(49) nanorods are grown on these SiC nanowires to form a double-layer nanostructure. XRD and TEM analysis revealed that the synthesized nanostructures are well cryst...
متن کاملHydrothermal Synthesis Of Tungsten Oxide (WO3) Nanostructures Using Sodium Chloride As Structure Directing Agent
Tungsten oxide (WO3) nanostructure were synthesized by a facile hydrothermal method at 150° C using tungstate dehydrates (Na2WO4.2H2O) as the precursor. Without any additive, scanning electron microscopy revealed a rhombus shaped WO3 nanostructures while with the addition of sodium chloride, the morphology changes to nano-dagger bundles that formed flower-like structure. Furthermore, the size o...
متن کاملNANO EXPRESS Controlled Growth of WO3 Nanostructures with Three Different Morphologies and Their Structural, Optical, and Photodecomposition Studies
Tungsten trioxide (WO3) nanostructures were synthesized by hydrothermal method using sodium tungstate (Na2WO4 2H2O) alone as starting material, and sodium tungstate in presence of ferrous ammonium sulfate [(NH4)2 Fe(SO4)2 6H2O] or cobalt chloride (CoCl2 6H2O) as structure-directing agents. Orthorhombic WO3 having a rectangular slab-like morphology was obtained when Na2WO4 2H2O was used alone. W...
متن کاملGrowth of Comb-like ZnO Nanostructures for Dye-sensitized Solar Cells Applications
Dye-sensitized solar cells (DSSCs) were fabricated by using well-crystallized ZnO nanocombs directly grown onto the fluorine-doped tin oxide (FTO) via noncatalytic thermal evaporation process. The thin films of as-grown ZnO nanocombs were used as photoanode materials to fabricate the DSSCs, which exhibited an overall light to electricity conversion efficiency of 0.68% with a fill factor of 34%,...
متن کامل