摩擦配向製作奈米結構於有機高分子太陽能電池之影響

Abstract

有機高分子太陽能電池相對其他種類太陽能電池具有輕薄、大面積、可撓曲、製作成本低的優點，其中又以混合異質接面結構最受矚目，近年來在此領域的進展極為快速，而在各個介面之間製造奈米結構以增加光電轉換效率就是一個重要的研究方向。本論文分為三個部分；首先介紹本實驗室初進入有機高分子太陽能電池領域時，所開發的標準樣品製程，接著介紹在PEDOT:PSS上以摩擦配向技術製作奈米溝槽對元件的影響，最後提出以此技術在主動層上製作奈米溝槽的潛在應用。 為了能夠確認奈米結構製程的效果，一個穩定的有機高分子太陽能電池標準製程是必要的；在開發有機太陽能電池標準製程的過程，我們針對厚/薄ITO玻璃的選擇、過濾步驟、以及退火溫度等參數做了測試；雖然受實驗室環境、儀器的限制，我們無法將標準片效率提升到如同參考文獻一般，但亦已發展到具有對照參考價值的標準元件製程。 接著，我們利用摩擦配向技術製作奈米溝槽於有機高分子太陽能電池的PEDOT:PSS膜上，在本實驗室環境成功將能量轉換效率由0.82 %提升至1.28 %；為了得到更進一步驗證，我們很榮幸能與王立義老師合作，並成功以摩擦配向技術將其實驗室標準元件之能量轉換效率由3.45 % 提升至3.82 %，這顯示摩擦配向製作奈米溝槽的方法能夠使用在不同環境、製程的系統中；同時我們也以原子力顯微鏡證實摩擦配向確實在PSDOT:PSS上製造出週期約500 nm、深度約10 nm之溝槽；此外，我們還量測了吸收光頻譜、光致螢光光譜、X光繞射分析、電洞遷移率，證實這些溝槽能提升結晶性並幫助光吸收上升，使電子電洞再結合率下降，以及提升電洞遷移率。 最後，介紹利用摩擦配向技術製作奈米溝槽於有機高分子太陽能電池主動層與陰極電極介面，並在本實驗室環境成功將光電轉換效率由0.82 %提升至1.20 %，而進一步的分析與討論就留待未來他人的開發研究。

總結而言，我們開發出有機太陽能電池領域前所未見的奈米結構製作技術，並證實其能幫助光電轉換效率提升，而且此技術的使用完全符合有機太陽能電池低成本製程、可大面積應用等特性，具有實際應用的潛能。

Compared with other solar cells, polymer solar cells have been widely noted due to the advantages including: easy fabrication, low cost, light, large area fabrication, and flexibility. It is an important research direction that fabricating nanostructure on differ-ent layer to enhance the efficiency. In this thesis, we adopt rubbing process, which is a low cost, simple and size-unlimited process, to produce nanostructure on PEDOT:PSS and active layer respectively, and execute some measurements to propose the reasons of efficiency enhancement. First of all, for the comparison of the effects of rubbing process, it is necessary to build up a standard fabrication of polymer solar cells. After some factors testing, in-cluding the choice of ITO film thickness, the use of filter, and the annealing temperature, we successfully established a stable fabrication process of standard polymer solar cells. Second, we introduced rubbing process into the fabrication of polymer solar cells. We produced nanostructure on PEDOT:PSS layer, and enhanced the conversion effi-ciency from 0.82 % to 1.28 % in our lab. For further understanding of this effect, we cooperated with Prof. Wang, and successfully enhanced the conversion efficiency from 3.45 % to 3.82 %. It revealed that rubbing process could be applied in different system. In addition, we used Atomic Force Microscope to prove the presence of nanostructure on PEDOT:PSS layer. We also measured the absorption spectrum, photoluminescence, X-ray diffraction, and hole mobility to certificate that rubbing-induced nanostructure could enhance light absorption, reduce recombination, increase hole mobility, and en-hance the crystallinity of PCBM. Finally, we used rubbing process to produce nanostructure on active layer, and we successfully enhanced the efficiency from 0.82 % to 1.20 %. Further research about this issue will be completed in the future. In conclusion, we have introduced rubbing process to the fabrication of polymer solar cells, and produced nanostructure to enhance the conversion efficiency. The ad-vantages of rubbing process are identical with polymer solar cells. Coupled with the feasibility of multilayer fabrication, it has large potential to benefit the commercializa-tion of polymer solar cells.