Transition metal sulfides are important semiconducting materials that are useful in various applications such as in solar cells and electronic devices. Different synthetic methods are available for the preparation of metal sulfide nanoparticles and thin films. However, the use of single source precursors (SSPs) is usually advantageous due to their suitability for both the synthesis of metal sulfide nanocrystals and deposition of thin films. SSPs also enable a better control over phase and stoichiometry. The current work demonstrates the synthesis of a range of novel gallium(III) alkyl xanthate complexes and their spectroscopic characterization and crystal structures. These complexes were used as suitable SSPs for the synthesis of gallium sulfide phase by solventless thermolysis. The effect of precursor structure on the molecular breakdown and in turn phase of gallium sulfide produced has been studied. Decomposition of the precursors at or near their breakdown temperatures produced no crystalline phases of gallium sulfide. Only with a prolonged heating immediately after decomposition were pure phases of Î³-Ga2S3 observed. In the next phase of this work, the synthesis of a series of metal (Cd, Ga and In) complexes of dithiocarbamate ligands and their spectroscopic characterization and thermal decomposition was investigated. Then, the mixture of two complexes was used to prepare Cd1-xGaxS and Cd1-xInxS (x = 0.02, 0.04, 0.06, 0.08 and 0.1) with excellent stoichiometric control achieved using the solvent-less method. The powder samples were characterised using several techniques to study the effect of dopants on structural, morphological and optical properties of the host material. Finally, indium thiospinel (MIn2S4 (M = Mn, Fe, Co, Ni, Zn and Cd)) nanoparticles and thin films were obtained using solventless thermolysis and aerosol-assisted chemical vapour deposition (AACVD) methods, respectively. The samples of powder and thin films were characterised using several advanced characterisation techniques to investigate effect of these methods on the structure, morphology and stoichiometry of the MIn2S4.
|Date of Award
|1 Aug 2020
- The University of Manchester
|David Collison (Supervisor) & David Lewis (Supervisor)