Abstract
Chapter 1 - IntroductionThe introduction provides an overview of metal oxides and their applications in industry. The basics of photovoltaic (PV) cells are described and the properties needed for each layer are discussed. The deposition techniques used to obtain thin films are also surveyed and the current precursors used in the deposition of Transparent Conducting Oxides are assessed. Finally, a rationale for the selection of the chosen ligand systems utilised in this thesis is presented and a decomposition pathway enabling their use in single source precursor development is proposed.
Chapter 2 – Synthesis of Zirconium amidates and deposition of ZrO2
This chapter focuses on the synthesis of six zirconium amidate compounds and their characterisation. Their thermal decomposition profiles were assessed by thermogravimetric analysis and the decomposition pathway was identified by trapping and analysing the by-products of thermolysis. Aerosol-assisted chemical vapour deposition (AACVD) was carried out in the temperature range 350 – 650 °C with the chosen precursor and analysis of the obtained films by XRD, SEM, UV/Vis spectroscopy
is discussed.
Chapter 3 – Synthesis of Zinc and Aluminium amidates and deposition studies
The synthesis and characterisation of hetero- and homoleptic zinc and aluminium amidate precursors is described. Their ability to act as single source precursors for the deposition of ZnO and doped ZnO thin films is analysed by thermogravimetric analysis. The chosen precursors are taken through to AACVD deposition studies. The obtained films are analysed by various analytical techniques and their ability to act as TCO layers is analysed by UV/Vis spectroscopy and resistivity measurements.
Chapter 4 - Deposition of SnS thin films from Sn(II) thioamidate precursors
This last chapter focuses on the deposition of SnS thin films. Two Sn(II) thioamidate precursors were synthesised by a simple isoelectronic replacement of a O atom in the amidate ligands for a S atom. As with the previous chapters, the thermal decomposition profile was analysed and the decomposition pathway was determined. Deposition studies were carried out and the purity of the obtained films was analysed by XRD and Raman. Preliminary EQE measurements were carried out to determine whether these films could be used as absorber materials in PV cells.
Chapter 5 - Future Work
This section lays out the future aims of the project and discusses what could be done to improve the obtained films.
Chapter 6 – Experimental
Detailed experimental procedures for the synthesis of the pro-ligands and metal (thio)amidate compounds with characterisation data including NMR and crystallography tables. Experimental details of the deposition processes for thin films is included alongside instrumental details and methods of analysis.
Chapter 7 – Appendix
List of compounds and a diagram of the equipment used in the collection of the volatile by-products of decomposition
| Date of Award | 12 Dec 2017 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Michael Hill (Supervisor) & Andrew Johnson (Supervisor) |