| Summary: | 碩士 === 國立聯合大學 === 光電工程學系碩士班 === 99 === In this study, the first part experiment was using E-gun evaporator to deposit TiO2 compact layer with different thickness and operating-current including 30mA, 40mA, 50mA, 60mA, 70mA and 80mA, but operating-voltage had been fixed at 7.5kv. After deposition, all specimens were annealed in the chamber. The second part experiment was deposited TiO2 compact layer by RF-sputtering and annealed in air, the deposition parameter had been fixed at constant. Finally, we will discuss the different between annealing and non-annealing. The optical properties of TiO2 compact layers were determined by UV/Vis/NIR spectrometer; mesoporous TiO2 layer was recorded by α-step; the microstructure of working electrode was carried out by FE-SEM; the crystal phase of TiO2 compact layer was detected by X-ray diffraction and the characteristics of dye-sensitized solar cells were analyzed with solar simulator.
According to the research results, as the operating-current and TiO2 compact layer thickness at 50mA and 75nm have the best light transmittance which crystal phase is rutile. The thickness of mesoporous TiO2 layer approx. 13μm, which in agreement with result of FE-SEM. The preparation condition at 30mA/75nm, 40mA/75nm, 50mA/50nm and 60mA/100nm has the best conversion efficiency which is 5.49%, 5.13%, 6.08% and 6.68%, respectively. The research result of second part shows non-annealing samples has higher transmittance than annealing samples, which deposition time at 25 min. when these samples were assembled as DSSCs, we could observe the overall conversion efficiency of annealing also lower than non-annealing which correspond with transmittance. On the other hand, no matter non-annealing or annealing samples are shown the best deposition time is 15 min due to it has higher conversion efficiency.
Therefore, in terms of results, we can demonstrate using physical method to prepare the TiO2 compact layer has higher light transmittance than chemical method, while the chemical method was applied to prepare TiO2 compact layer that will produce a haze surface, and we can understand from literature, that is, the TiO2 compact layer can increase the fill factor and prevent the dark current production.
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