Exploring the Potential of Metal Xanthate Precursors for the Synthesis of Doped and Quaternary Metal Sulfides

UoM administered thesis: Phd

  • Authors:
  • Abdulaziz Alanazi

Abstract

Metal sulfide nanomaterials thin films are important in photovoltaic applications due to their exciting properties. Xanthate complexes are well known for the deposition of metals sulfide films and nanomaterials. This produces suitable chemical and physical properties to deposit films with a very low level or no contamination at low temperature. Different synthetic protocols are available for preparation of metal sulfide nanomaterials and/or thin films. Nonetheless, the use of single source precursors is usually advantageous, as they can be used for the synthesis of metal chalcogenide nanocrystals, and are equally suitable for the deposition of thin films. Furthermore, a better control over stoichiometry and phase can be achieved, due to preformed bonds between metal and chalcogen atom. The work shows the synthesis of a series of novel manganese complexes of xanthate ligands, their spectroscopic characterization, crystal structures and thermal decomposition have been studied. The complexes were used as single source precursors for the production of MnS nanocrystals and thin films. MnS nanocrystals have been synthesised by hot injection and solvent-less thermolysis at 230 °C and 350 °C, respectively. In addition, MnS thin films have been synthesised by doctor blade method at 350 °C. The nanocrystals and films were characterised by powder X-ray diffraction, Raman spectra, scanning electron microscopy and energy dispersive X-ray spectroscopy. Additionally, xanthate complexes of lead has been used for the production of Mn-doped PbS nanocrystals using solvent-less thermolysis, adding with a low concentration of Mn source. The nanocrystals were characterised by several techniques to study the formation behaviour, structure and chemical composition. Finally, we report the use of copper, manganese, iron and tin xanthates in solvent-less thermolysis to produce stannite Cu2MnSnS4 (CMTS) nanoparticles and Cu2FeSnS4 (CFTS) powders at temperatures between 250 and 500 °C. Higher temperatures give the normal tetragonal phase CMTS and CFTS, while low temperatures are contaminated with cubic phases.

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Original languageEnglish
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Award date31 Dec 2020