M. Ing. (Electronic and Electrical) / Porous silicon has been obtained by anodizing monocrystalline silicon in hydrofluoric acid solutions. The experimental conditions needed to obtain this material are described. A scanning electron microscopy study revealed the morphology of the pores. The diffusion-limited model is the current accepted model explaining the formation of porous silicon. The structure of porous silicon formed on lightly doped n-type silicon does, however, not agree with the morphologies predicted by the basic model. The model was·therefore extended to include the n-type observations. The observed straight pores, the fluctuation of pore length and the double layered structure were succesfully simulated. Visible photoluminescence were obtained from p-type porous silicon. The properties of the emitted light were investigated together with the quantum confinement and siloxene models describing this behaviour of porous silicon. The effect of the anodizing parameters on the electroluminescence visible during the anodic oxidation of porous silicon were investigated leading to additional proof of the quantum confinement model. A model describing the band structure of the silicon-electrolyte system during electroluminescence is proposed.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:10566 |
| Date | 10 April 2014 |
| Creators | Malan, Daniel Francois |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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