以先進奈米結構增進高分子太陽能電池特性:電漿增益與轉印製程的應用

Abstract

有機太陽能電池有著大家所熟知的眾多優勢，如低成本，可撓曲，製程只須低溫且容易等，使其受到廣泛的重視與研究，如今有機太陽能電池內部量子效率已達100%的情況下，因此增加元件有效的光吸收效率是我們能提升有機太陽能電池效率的另一途逕。本博士論文著重於利用金奈米粒子產生侷域性表面電漿共振效應應用在有機高分子太陽能電池的材料合成與其增益的探討。 首先，我們將奈米金粒子藉由檸檬酸鈉還原並合成於氧化石墨烯薄片上，我們利用一包覆劑添加於合成過程中，去抑制奈米金粒子的聚集。我們還使用另一個還原劑-甘胺酸，相較於檸檬酸鈉，甘胺酸對環境更為友善，此外，使用甘胺酸還原奈米金粒子並合成於氧化石墨烯上時，其奈米金粒子並不會聚集，因此這樣的合成過程更簡單更乾淨。另一方面，我們在合成步驟中加入了含胺基的聚乙二醇，來改進石墨烯奈米複合物在有機溶劑中的溶解度，再將奈米金粒子由檸檬酸鈉還原並合成於氧化石墨烯。這樣的複合物即擁有兩親性，可溶於水與有機溶劑。如此的兩親性複合物則可同時溶進聚二氧乙基噻吩聚苯乙烯磺酸(PEDOT:PSS)與主動層溶液，所有元件皆藉由侷域性表面電漿共振效應提升了有機太陽能電池的元件效率。 繼氧化石墨烯後，二硫化鉬是另個新興具潛力的二維材料，擁有許多出色的特色。我們利用簡單的物理方法剝除二硫化鉬，成為單層或極少層數的二硫化鉬，再將金粒子利用自發性的反應合成上二硫化鉬表面。接著再將合成後的二硫化鉬複合物應用於我們的有機太陽能電池。最後，我們也介紹了一種不需使用聚二甲基矽氧烷(PDMS)，新穎的轉印製程方法，為將來大量製程有機太陽能電池，開拓一條新的道路。

Organic photovoltaics (OPVs) possesses many advantages, including low-cost fabrication, mechanical flexible, easy to process and low process temperature. The internal quantum efficiencies of the state-of-art OPVs are approaching close to 100%. Therefore, the absorption efficiency of the organic solar cell is another limitations and could be improved for further increasing their high external quantum efficiencies and power conversion efficiencies. This dissertation aims to investigate the effects of localized surface plasmon resonance (LSPR) on the performance of polymer solar cells using gold nanocomposites..

First, we reduced the gold nanoparticles (NPs) by sodium citrate and anchored the gold NPs on the graphene oxide (GO) sheets simultaneously. We applied the capping agent to prevent the aggregation of Au NPs. After that, we utilized anther reducing agent-glycine- to reduce the gold NPs. Comparing with the sodium citrate, the glycine is more environmental friendly. Besides, using the glycine in the synthesis process, the gold NPs had better distribution on the GO sheets. Therefore, the synthesis process is simpler and clean. Further, we applied the PEG-NH2 in the synthesis process to improve the sobility of the nanocomposites in organic solvents. The nanocomposites after PEGylation had the amphiphillic property, and they could be dissolved in deionized water and organic solvents. We could dope the amphiphillic nanocomposites in the Poly(3,4-ethylenedioxythiophene) Polystyrene sulfonate and the active layer of the OPVs simultaneously to realized dual plasmonic structures. All the device preformance had been significant improving due to the LSPR effects. MoS2 is another promising two-dimensional material with many excellent properties. We used a simple method to exfoliate MoS2 sheets to few layers. A spontaneous reaction with Au ions of the MoS2 sheets occured after mixing the HAuCl4 and MoS2 solutions. Then we employed the Au/MoS2 nanocomposites as the electron transport layer in the OPVs. Finally, we introduced a novel transfer-printing process without using polydimethylsiloxane. The technology would be another choice for the mass production.