混摻硒化鎘奈米棒/聚對苯乙烯衍生物應用於有機太陽能電池之研究

Abstract

本論文利用熱裂解法合成硒化鎘奈米棒，並應用在有機太陽能電池領域。在製備過程中改變不同反應時間、前驅物的比例，並且用穿透式電子顯微鏡來觀察奈米棒的變化。隨後在奈米棒進行表面改質，以進行下一步元件的製備。在元件的製備上，將硒化鎘奈米棒和共軛導電高分子MDMO-PPV混摻製成有機高分子太陽能電池，討論不同混摻比例對太陽能電池光電轉換效率的影響。並在元件上施加不同偏壓，來提升元件效率。發現在混摻硒化鎘奈米棒/MDMO-PPV重量比為14:1的比例下，有最佳的光電轉換效率0.83 %。而在施加四伏特的偏壓、持續時間四分鐘後，在模擬光源AM1.5G 100 mW/cm2的照射下，短路電流從原本的3.08 mA/cm2增加到3.83 mA/cm2；填充因子從0.30增加到0.35；光電轉換效率從0.83 %增加到1.26 %，增加了52 %。另外，在外部量子效率測量上，在加完偏壓後，也從28 %提高到42 %。推測加偏壓可能改善硒化鎘奈米棒的排列方式，使得電子更容易傳輸到電極上，提升元件效率。

In this thesis, we incorporated Cadmium Selenium (CdSe) nanorods into poly(2-methoxy-5-(3’,7’-dimethyloctyloxy)-1,4-phenylenevinylene) (MDMO-PPV) to make hybrid solar cell devices, and applied electric field in that to enhance their performance. First, we used chemical method to synthesize CdSe colloidal nanorods. The size was determined by Transmission electron microscopy (TEM). Second, the surface modification of CdSe nanorods is necessary to hybrid inorganic semiconductors with conjugated polymers, and we treated CdSe nanorods with pyridine ligand on their surface. At last, we incorporated pyridine modified CdSe nanorods into MDMO-PPV as hybrid solar cell. We fabricated solar cells with various blend weight ratios of CdSe nanorods with MDMO-PPV to study the optimum device performance. We found the short circuit current density of the solar cell increased after applied electric field within it. After applied electric field, device power conversion efficiencies increased up to 1.26 %(compare with no bias voltage, enhancement exceeding 50 %) under AM1.5G illumination for a device containing 93 wt% of nanoparticles.