Ph.D. / The aim of this study was the development of a new technology for the manufacturing of amorphous silicon (a-Si:H) solar cells on flexible substrates. Kapton R , a commercially available polymer, was used as a substrate to this end. The use of such a polymer, as opposed to glass, results in dramatic savings and also affords the possibility for technological innovation. From the start the project was planned to develop and commission a medium-scale pilot plant manufacturing process. The project thus consisted of two sections: the design, fabrication and implementation of a large-area deposition system, as well as research and development of the materials and cells. A pilot plant was developed and successfully implemented. The optimization of the reactor resulted in very homogeneous materials with good electrical- and optical characteristics. The individual materials were optimized and incorporated into the standard cell configuration (on glass). This process was then transferred to kapton and the configuration was optimized. The use of kapton, as opposed to glass, implies the growth of silicon on a metal film on the kapton. This process leads to a number of phenomena occurring in cells on kapton which do not occur in standard cells on glass. The phenomena include the crystallization of a-Si:H at low temperatures, degradation of the material properties and unwanted microstructure. The origin of these phenomena can be linked to the high occurence of metal/Si-interdiffusion. It was found that this inter-diffusion can be decreased by the insert i on of a thin ZnO buffer layer between the back metal contact and the a-Si:H. The flexible cells were successfully developed and optimized for large areas. An operational manufacturing process was thus developed and the product of this study can now be applied successfully in practical applications.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:9207 |
| Date | 14 August 2012 |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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