大氣下以蒸鍍輔助溶液之二階段製程鈣鈦礦太陽能電池與石墨烯陽極備製有機正規太陽能電池之研究

Abstract

本篇論文前半段旨在探討以蒸鍍輔助溶液(VASP)兩階段製程所做出的鈣鈦礦太陽能電池之效能。從二階段製成的前半段，PbI2旋轉塗佈於PEDOT:PSS開始，我們一步一步優化元件的每一層，並探討了不同參數情況下元件表現優劣的原因。我們用SEM檢視了不同轉速塗佈之PbI2與MAI反應後鈣鈦礦層的厚度，同時，也探討了熱蒸鍍過程中出現的表面型態問題與對元件造成的影響。接著我們討論了後退火對於鈣鈦礦主動層的影響，與改變元件表現的機制，並找到了適當的後退火時間，將元件的效率提升至10.26％。並且，我們去了解了電子傳輸層PCBM([6,6]-phenyl-C61-butyric acid methyl ester)用在鈣鈦礦太陽能電池中所扮演的角色，還有對元件效率提升提供的輔助，在優化條件下，元件的轉換效率提升至10.40％。最後我們測試了緩衝層Ca的適當厚度，使得元件在11％左右的轉換效率之下，還可以有不錯的填充係數表現。 在第二部分的實驗中，我們以一種親疏水介面材料HBC-6ImBr來對石墨烯電極進行改質而做出以石墨烯為陽極的正規有機太陽能電池。有了HBC-6ImBr的介面，原本親水的PEDOT：PSS因此可以與石墨烯/HBC-6ImBr電極連接在一起，使得後續的材料都可以順利的接續塗佈下去。在本章中我們對塗佈不同層數HBC-6ImBr的元件做了AFM的量測，發現當HBC-6ImBr的層數增加，電極表面因為HBC-6ImBr分子聚集而造成的不均勻現象以及破洞，會逐漸地被彌平，元件的填充係數因此獲得提升至百分之五十，以及串聯電阻下降至28.46Ω/cm2。但是由於HBC-6ImBr分子本導電性並不好，因此，最優化的元件是在三層HBC-6ImBr分子的情況之下，以PI(P3HT:ICBA)為主動層之正規太陽能電池之光電轉換效率可以到達3.65％，填充係數可以達到百分之五十以上。

In this study, performance improvement of Perovskite solar cells using two-step vapor-assisted solution process(VASP) has been achieved. Through experimental optimization, solar cell with optimal structure have been carried out and the mechanisms behind have been discussed in detail. Via scanning electron microscopy(SEM), the thickness profile and the morphological variation for Perovskite film obtained in different ways were investigated systematically. Next, the influence of post-annealing on device performance was verified by X-ray diffraction(XRD), suggesting that appropriate post treatment is crucial to the quality of active layer as well as the resulting performance. This is in addition to the study of passivation effect developed by PCBM([6,6]-phenyl-C61-butyric acid methyl ester) electron transport layer and also the Ca buffer incorporation, resulting in further improvement with decent fill factor for proposed devices. Based on these findings, the power conversion efficiency for Perovskite solar cells with an optimal device configuration has achieved over 11%. Further, a buffer material, HBC-6ImBr(Hexa-peri-hexabenzocoronene-6ImBr), was employed to enable hydrophilic properties for the hydrophobic graphene, allowing graphene bottom anode for conventional organic photovoltaics(OPV). With the aid of HBC-6ImBr, the aqueous PEDOT:PSS can be deposited onto graphene anode uniformly; hence the following fabrication process can be achieved to complete the solution-processed OPV. The morphological studies of graphene/HBC-6ImBr composite films were performed via atomic force microscope(AFM) to check the capabilities of surface modification. In the end of this thesis, a decent power conversion efficiency of 3.65% with a fill factor around 50% for P3HT:PCBM BHJ solar cell using graphene anode has been achieved by incorporating the anode modification of tri-layer HBC-6ImBr.