Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds
A simple and versatile pyrolytic method of preparing thin metal oxide films that is based on the Metal Organic Chemical Vapour Deposition (MOCVD) technique and that is operative at relatively low temperatures (420°C) has been utilised to prepare the thin metal oxide films of indium, zinc, aluminium...
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Obafemi Awolowo University
2014
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| author | Lambi, John Ngolui |
| author2 | Ajayi, O.B. |
| author_facet | Ajayi, O.B. Lambi, John Ngolui |
| author_sort | Lambi, John Ngolui |
| collection | DSpace |
| description | A simple and versatile pyrolytic method of preparing thin metal oxide films that is based on the Metal Organic Chemical Vapour Deposition (MOCVD) technique and that is operative at relatively low temperatures (420°C) has been utilised to prepare the thin metal oxide films of indium, zinc, aluminium and copper from the appropriate metal acetylacetonate or carboxylate.
To fully understand the pyrolytic route leading to film formation, the thermal decomposition of some of the starting materials was investigated in detail at 420°C in air and N,, using separately, a Muffle furnace and a flow system. The identities of the products as determined by a combination of techniques are Cu, CO2, a carboxylic acid and an odd chain-length alkene, in the case of the copper(II) soaps; ZnO, CO2 and a ketone for the zinc soaps; and a mixture of Cu, Cu20 and CuO in the case of the copper(II) acetylacetonate. While mechanisms have been proposed to account for the degradative routes of the soaps, which of the metal acetylacetonates is still inconclusive.
A combination of Ion Beam, X-ray and optical absorption studies have shown that the oxide films of indium, zinc and aluminium are, of the expected stoichiometry, while that of copper is of mixed composition (CuO/Cu2O/Cu). It is not immediately clear why carbon and alkali metal contamination was observed for the Al2O3 and CuO/Cu2O/Cu films but not for the In2O 3 film. Scanning Electron Microscopy (SEM) has shown the films to be polycrystalline.
The observed optical characteristics (high transmittances, T = 75-90%; moderate reflectances, R < 21%; low absorbances, A < 8%; high refractive indices, nf > 1.5 and low extinction coefficients, k < 0.4) are as expected for these thin films.
Potential uses of these thin layers based on their observed properties are also discussed. |
| format | Thesis |
| id | oai:ir.oauife.edu.ng:123456789-3442 |
| institution | My University |
| language | English |
| publishDate | 2014 |
| publisher | Obafemi Awolowo University |
| record_format | dspace |
| spelling | oai:ir.oauife.edu.ng:123456789-34422023-05-13T11:10:26Z Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds Lambi, John Ngolui Ajayi, O.B. Akanni, M.S. Organic metal pyrolytic carboxylic acid stoichiometry scanning electron microscopy (SEM) A simple and versatile pyrolytic method of preparing thin metal oxide films that is based on the Metal Organic Chemical Vapour Deposition (MOCVD) technique and that is operative at relatively low temperatures (420°C) has been utilised to prepare the thin metal oxide films of indium, zinc, aluminium and copper from the appropriate metal acetylacetonate or carboxylate. To fully understand the pyrolytic route leading to film formation, the thermal decomposition of some of the starting materials was investigated in detail at 420°C in air and N,, using separately, a Muffle furnace and a flow system. The identities of the products as determined by a combination of techniques are Cu, CO2, a carboxylic acid and an odd chain-length alkene, in the case of the copper(II) soaps; ZnO, CO2 and a ketone for the zinc soaps; and a mixture of Cu, Cu20 and CuO in the case of the copper(II) acetylacetonate. While mechanisms have been proposed to account for the degradative routes of the soaps, which of the metal acetylacetonates is still inconclusive. A combination of Ion Beam, X-ray and optical absorption studies have shown that the oxide films of indium, zinc and aluminium are, of the expected stoichiometry, while that of copper is of mixed composition (CuO/Cu2O/Cu). It is not immediately clear why carbon and alkali metal contamination was observed for the Al2O3 and CuO/Cu2O/Cu films but not for the In2O 3 film. Scanning Electron Microscopy (SEM) has shown the films to be polycrystalline. The observed optical characteristics (high transmittances, T = 75-90%; moderate reflectances, R < 21%; low absorbances, A < 8%; high refractive indices, nf > 1.5 and low extinction coefficients, k < 0.4) are as expected for these thin films. Potential uses of these thin layers based on their observed properties are also discussed. 2014-06-25T09:50:26Z 2018-10-29T11:08:25Z 2014-06-25T09:50:26Z 2018-10-29T11:08:25Z 1987 Thesis APA http://localhost:8080/xmlui/handle/123456789/3442 en pdf application/pdf Obafemi Awolowo University |
| spellingShingle | Organic metal pyrolytic carboxylic acid stoichiometry scanning electron microscopy (SEM) Lambi, John Ngolui Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds |
| title | Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds |
| title_full | Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds |
| title_fullStr | Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds |
| title_full_unstemmed | Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds |
| title_short | Preparation and Characterisation of Pyrolytically-Deposited Thin Oxide Films from Metal-Organic Compounds |
| title_sort | preparation and characterisation of pyrolytically deposited thin oxide films from metal organic compounds |
| topic | Organic metal pyrolytic carboxylic acid stoichiometry scanning electron microscopy (SEM) |
| url | http://localhost:8080/xmlui/handle/123456789/3442 |
| work_keys_str_mv | AT lambijohnngolui preparationandcharacterisationofpyrolyticallydepositedthinoxidefilmsfrommetalorganiccompounds |