本論文研究高分子-富勒烯為主動層之體異質接面(Bulk heterojunction，BHJ)有機太陽能電池，探討利用外加電場輔助製作主動層薄膜對有機太陽能電池之光伏特性的影響。主動層材料以高分子poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'- benzothiadiazole)] (PCDTBT) 當電子供體，富勒烯的衍生物[6,6]-phenyl-C61- butyric acid methyl ester (PCBM) 當電子受體，使用氯苯為溶劑，配製PCDTBT與PCBM之混合溶液，利用旋轉塗佈方式製作主動層薄膜，於主動層薄膜乾燥過程中施加電場，協助成膜。利用拉曼光譜儀、吸收光譜儀、原子力顯微鏡及X光繞射光譜儀分析主動層薄膜光學性質與微結構，研究電場輔助成膜對主動層薄膜微結構與太陽能電池元件光伏特性的影響。
光伏電特性的結果顯示，當使用PCDTBT:PCBM重量混摻比為1:2時，且於薄膜乾燥過程施加6x105 V/m垂直基板向上的電場所製作的主動層，電池元件的短路電流有明顯提昇，最佳的光電轉換效率可達3.4 %，相較於未加電場的元件則僅有2.8%。電特性的分析結果發現主動層經過施加電場後之元件，其並聯電阻有上升以及串聯電阻則有下降的趨勢，因此，改善太陽能電池的光電轉換效率。
利用光譜學方法分析電場輔助成膜對主動層薄膜微結構的效應，拉曼光譜分析結果指出，相較於未施加電場，有施加電場製作的主動層薄膜的最強波鋒有紅位移指現象，且有較小半高寬。紫外-可見吸收光譜的分析結果，則指出施加電場可增強其吸收強度，並伴隨紅移現象。上述結果建議電場輔助成膜可使PCDTBT高分子的增加有效共軛鏈長，使分子間的排列較均勻，進而提升主動層薄膜的吸收強度，可產生較多的激子數，並改善載子的傳輸，使得元件的短路電流提高，改善元件的光電轉換效率。

In this study, the photovoltaic characteristics of electric field assisted fabrications of polymer–fullerene bulk heterojunction (BHJ) organic solar cells were investigated. To prepare the active layers of BHJ organic solar cells, poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl- 2',1',3'-benzothiadiazole)] (PCDTBT) and fullerene derivatives [6,6-phenyl C61-butyric acid methyl ester (PCBM) were used as the electron donor and the electron acceptor, respectively. The PCDTBT:PCBM blended active layers were prepared by spin-coating from chlorobenzene solution, then an external electric field was applied during the drying process. We studied the effects of electric field assisted fabrications of active layers on the microstructures of the active layers and the photovoltaic properties of the solar cells. The active layers were characterized using Raman spectroscopy, absorption spectroscopy, atomic force microscopy and x-ray diffraction.
For the photovoltaic properties, we found that the BHJ organic solar cells that were made using the PCDTBT:PCBM weight ratios of 1:2 show the best power conversion efficiency (PCE) of 3.4% when an electric field of 6x105 V/m in a vertically upward direction with respect to the substrate was applied. In contrast, the reference solar cells, which the active layer formation without applying any electric field, only showed the PCE of ca. 2.8 %. As compared to the reference cells, we observed an increase in the shunt resistance and a reduction in the series resistance of the solar cells with electric field assisted fabrications of the active layer, thus supporting higher PCE.
For the PCDTBT:PCBM films with electric field assisted fabrications, Raman spectroscopy analysis results revealed a red-shift and narrow full width at half maximumof the strongest Raman band when a 532 nm excitation line was used. Meanwhile, an enhanced absorbance in the 450-650 nm was observed and associated red-shift. Above-motioned observations suggested that applied electric field during film formation resulted in films with improved effective conjugation length and better homogeneity of the PCDTBT chains, thus higher absorbance. This provides a reasonable basis for the formation of a relatively large amount of excitons and for improving charge transport, thus higher photocurrent and PCE of the solar cells

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