Aerosol assisted chemical vapor deposition (AACVD) synthesis of nanostructured cauliflower patterning in MWCNT doped tungsten oxide
| Autor: | Russell Binions, Saima Shaukat, I.M. Dildar, Muhammad Khaleeq-ur-Rahman |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Tungsten hexacarbonyl Materials science Band gap Scanning electron microscope Process Chemistry and Technology Doping chemistry.chemical_element 02 engineering and technology Substrate (electronics) Chemical vapor deposition Tungsten 021001 nanoscience & nanotechnology 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Chemical engineering 0103 physical sciences Materials Chemistry Ceramics and Composites Grain boundary 0210 nano-technology |
| Zdroj: | Ceramics International. 45:1918-1927 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2018.10.084 |
| Popis: | We report nanostructured tungsten oxide (WO) cauliflowers for the first time that are fabricated onto silica glass substrate at 400 °C by aerosol assisted chemical vapor deposition using tungsten hexacarbonyl and multiwalled CNTs in toluene. The deposited films are characterized by Scanning electron microscopy, Energy dispersive x-ray spectroscopy, X-ray diffractometry, Fourier transform infrared and UV–VIS spectroscopy and four-point probe for microstructural, optical and electrical properties. Surface morphology exhibits the growth of nanocauliflowers followed by the aggregation of spherical nanoparticles with high angle grain boundaries. Structural information reveals the transformation of triclinic to tetragonal phase with preferential switching from (0 2 0) to (0 0 1) plane having signatures of W-O-W symmetric vibration between (700cm -1 and 900 cm −1 , somewhat perturbed by the addition of doping. In additions, films show inconsistent variation in electrical resistivity (15–10 9 ) Ω-cm due to agglomeration of MWCNTs at grain boundaries and appearance of “nanocracks” due to ionic radii mismatch of tungsten and CNTs at higher doping ratios. Black color films present decrease in optical transmittance for range of 300–400 nm attributed to trapping sites and defects generated due to incorporation of multiwalled CNTs. The splitting of Fermi level as a result of incorporation of MWCNTs caused the increase of band gap energy in range of 3.18 eV, useful in tungsten oxide based new material system which can act as the light harvesting material and energy storage simultaneously. |
| Databáze: | OpenAIRE |
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