QC425 : Synthesis and Characterization of WS2 Nanostructures
Thesis > Central Library of Shahrood University > Physics > MSc > 2018
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Abstarct: Transition mextal dichalcogenides (TMDs), such as WS2 and MoS2, have been widely explored for their utilization as two-dimensional (2D) semiconducting nanomaterials with unique electronic, optical, mechanical and catalytic properties. In this thesis, tungsten disulfide nanostructures were synthesized using hydrothermal and RF sputtering techniques. Structural, elemental composition, surface morphological and optical properties of synthesized samples were studied using XRD, EDAX, Raman, SEM and UV-Vis spectroscopy. In the first part of this thesis, WS2 nanostructures were synthesized using three different amounts of CTAB as a surfactant with two different precursors of thiourea and sodium sulfide as sulfur sources by hydrothermal technique. XRD pattern analysis showed the formation of hexagonal crystal structure for all samples and Raman spectroscopy confirmed this result. EDAX analysis detected the presence of W and S elements in the synthesized samples. The band gap of samples prepared using thiourea as precursor decreased from 3.94 to 2.04 eV by increasing the amount of CTAB in the precursor solution. For sodium sulfide it changed from 3.27 to 1.27 eV by increasing the amount of CTAB. SEM images showed the formation of nanoplates for samples prepared using sodium sulfide as precursor. In the second part, the results of the WS2 synthesis was reported using RF sputtering. Samples were coated using different Argon gas pressure on glass substrates at the temperature of 250 °C. All samples were amorphous. Raman spectroscopy confirmed the formation of WS2. Band gap of samples were increased from 3.37 to 3.84 eV by increasing the amount of Argon in the environment during the coating process.
Keywords:
#transition mextal dichalcogenides; tungsten disulfide; hydrothermal #RF sputtering; 2D nanostructure Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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