| Summary: | 碩士 === 長庚大學 === 機械工程學系 === 99 === Nowadays, many environmentally advanced countries in the face of global warming, environmental pollution and energy depletion challenges including rising fuel prices and fuel supply shortage, are trying to develop green energy. Therefore, the development of green energy, including solar, wind, hydro, etc., has become the world's industrial development trend. Among them, the thin-film solar panel can be a favorable product of Taiwan’s industry because its coating process is similar to that of LCD panels. However, for large area coating, the study on the thickness uniformity is quite rare. Therefore, the purpose of this study is to seek production factors that give an even flow in the vacuum chamber and consequently deposits the thin films with even thickness on large sized thin-film solar cells.
In this study, the coating method is the microwave electron cyclotron resonance plasma enhanced chemical vapor deposition. Substrates are coated with micro-crystal silicon thin film to produce large size (1.1 m × 1.4 m) thin film solar cell devices. To study the chamber flow field in vivo effects of coating thickness, we used Pro/Engineer, COMSOL® 3.4 to create a numerical model and simulation analysis in the flow field. In the meantime, the parameters involved are: model segmentation grid size settings, the positions of chamber air inlet and outlet, gas flow rate, ion source positions, the distance between the substrate and the chamber. Finally, the dependencies between the positions of gas inlet and outlet to the positions of ion source are verified. The results show that to get the best uniformity of film thickness, the heights of gas inlet and outlet are 169 mm and237 mm, respectively. The size of ion source region is 230 × 230 × 20 mm. The height of the ion sources varies from 154 mm to 179 mm with the periphery ion sources locating lower than the internal ion sources. The gas inlet velocity does not affect the uniformity of film thickness, because the Péclet number of the flow is much smaller than 1. Finally, the variation of the film thickness is within 5 %, which reaches our goal. Furthermore, the growth rate of the film thickness is 1.29 nm/s, which is no less than those published in the literature.
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