Summary: | 碩士 === 國立成功大學 === 光電科學與工程研究所 === 96 === In this thesis, the silicon oxide was deposited on crystalline silicon solar cells as a passivation layer as well as an antireflection coating by Photo-CVD using a Deuterium lamp as the excitation source at a lower temperature (<300oC)
Deuterium lamp radiates the light wavelength form 190 to 400nm which is in ultraviolet region. It can effectively excite O2 and SiH4 reacting to grow silicon oxide on the substrate at a lower temperature. In our experiment, the pressure of chamber was fixed at 300 mTorr, and the process gas ratio (R=O2/SiH4) was changed to 0.5, 1, 2, respectively. At the same time, the process temperature also was changed from 100oC, 200oC to 300oC. For all recipes, the silicon oxide films were deposited on polished silicon substrate. The characteristics of SiO2 films will be investigated by analysis of Ellipsometer, Atomic Force Microscope (AFM), Fourier Transform Infrared Spectrometer (FTIR), Secondary ion Mass Spectrometry (SIMS), Focused Ion Beam (FIB). Capacitance-Voltage (C-V) measurement was used to calculate the interface state density and analyze the interfacial quality. For all process recipes, the silicon oxide was deposited on crystalline silicon solar cell with thicknesses of 10, 20, 30 nm, respectively. Finally, the weight average reflection, open-circuit voltage, short-circuit current density, fill factor and efficiency of solar cells were measured. We also discuss the relation with thin films and devices analysis.
The best performance is at R=2, T=300oC. The lowest value of interface state density is 5.37×1011 (eV-1cm-2). The short-circuit current density is more compared with standard in our experiment.
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