以奈米銅粒子製作表面電漿增益之有機高分子光伏元件

Abstract

本論文主要在研究利用奈米銅粒子製作表面電漿增益之有機光伏元件。研究主要分成兩部分，第一部分為利用氧化還原反應合成奈米銅粒子，經實驗結果比較後，選擇最佳的氯化銅濃度為0.01 M，合成出來的奈米銅粒子經過濾處理後，可以得到粒徑大小約為200 nm的奈米銅粒子。第二部分為應用奈米銅粒子於製作表面電漿增益之有機光伏元件，使用主動層材料為PBDTTT-EFT：PC71BM之元件，在摻入奈米銅粒子後，元件的電性表現會因為奈米銅粒子誘導之表面電漿效應而有大幅提升，在AM 1.5G的太陽光照射下，能量轉換效率可達6.82%，短路電流密度、填充因子和開路電壓，分別為13.34 mA/cm2、 0.65和0.79 V。另一方面，使用室內光源進行量測時，摻有奈米銅粒子的元件，其最高能量轉換效率可達14.31%。進一步比較元件吸收光譜及外部量子效率的增益波段，可以發現該波段與奈米銅粒子引發之表面電漿共振效應吻合，因此我們可以確認元件電性表現的提升是因為奈米銅粒子引發之表面電漿共振效應所導致。

This study aims at producing surface plasmon enhanced organic photovoltaic devices using copper nanoparticles. The research is divided into two parts. The first part focus on the synthesis of copper nanoparticles(CuNPs) by a redox reaction. Based on the experimental results, the optimized concentration of copper chloride was 0.01 M. After the synthetic reaction and proper filtration, the CuNPs, which exhibited an average particle size of 200 nm, could be generated. The second part is the applying copper nanoparticles to produce surface plasmon enhanced organic photovoltaic devices. The active layer was a blend of poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PBDTTT-EFT) and [6,6]-Phenyl-C71-butyric acid methyl ester (PC71BM). After the incorporation of CuNPs, the electrical characterization was dramatically improved owing to the surface plasmon resonance induced by the CuNPs. The energy conversion efficiency could reach 6.82% under one sun illumination; the short-circuit current density, fill-factor, and open-circuit voltage were 13.34 mA/cm2, 0.65, and 0.79 V, respectively. On the other hand, under indoor light conditions, the highest energy conversion efficiency of the devices prepared with CuNPs could reach 14.31%. In addition, comparison of absorption spectrum of the device and its spectrum of external quantum efficiency well matched to the surface plasmon resonance band of the CuNPs. Therefore, we confirm that the improved electrical characterization is attributable to the surface plasmon resonance induced by the CuNPs.