新穎倒置結構之有機太陽能電池

Abstract

本研究主要是探討一種倒置結構之有機太陽能電池，此倒置結構之元件，擁有氧化鋅薄膜作為一個電子傳輸層，鍍上P3HT:PCBM作為光反應層，並利用PEDOT:PSS 當作電洞傳輸層，最後蒸鍍上銀電極。相對於傳統式的有機太陽能電池，倒置結構使用功函數較高的電極，移除了原本較低功函數容易產生氧化的鋁電極，可以有效地提升有機太陽能電池的壽命。本文中探討了紫外光對於氧化鋅電子傳輸層產生的效應，以及對倒置太陽能電池元件效率的影響，並量測電子電洞的結合效率。此外，我們還介紹了使用石墨烯氧化物以及石墨烯在倒置有機太陽能電池中作為一個電洞傳輸層，取代了傳統的PEDOT:PSS，並且展現了不錯的效率。最後，我們利用熱脫膠轉印的方式，作出了一個以石墨烯為上電極，石墨烯氧化物為電洞傳輸層而氧化銦錫作為下電極的半透明式倒置有機太陽能電池。為了達到更高的效率，我們改善了原本的製程，減少石墨烯層與層之間的殘留物，使得效率提升到約莫2.5%。此外，利用兩邊電極皆為透光的特性，可以利用一面反射鏡，對元件進行兩面照光，使得光電流有進一步的提升。

In this study, we demonstrated an inverted polymer solar cell which has ZnO thin film as an electron transport layer, P3HT:PCBM as an active layer, PEDOT:PSS as a hole transport layer, and silver as the top electrode. Compared to the conventional devices, because of the high work-function metal electrode, inverted PSCs are more air-stable. In the following chapter, the UV effect on ZnO electron transport layer and the impact to device performance were investigated. Then, the using of graphene and graphene oxide to substitute for PEDOT:PSS as a hole transport layer was introduced. J-V characteristics were investigated to compare the device performance of the devices with different hole transport layers. Finally, we constructed a novel structure with graphene as a top electrode, graphene oxide as a hole transport layer and ITO as a bottom electrode. Because of the two transparent electrodes, this device is semitransparent, and a modified-transferring process was introduced for further improvement of the device performance.