八噻吩雙軸共軛高分子於有機與有機無機混成鈣鈦礦太陽能電池之應用

Abstract

在近年的溶液製成太陽能電池研究中，為了使有機太陽能電池能夠在全光譜吸收範圍都能有更寬廣的吸收範圍，不僅使用可吸收紅光波段的小分子作為受體外，更希望能增加近紫外光波長區域的吸收得到全光譜吸收的有機太陽能電池。因此，我們設計寬能隙(Eg)高分子的八噻吩雙軸共軛性高分子(8T-based polymers)。藉由在高分子主鏈上引入由龐大且共軛的噻吩側鏈與共軛結構上的π-π 效應，除了原本主鏈結構於可見光波段之吸收外，可於近紫外光波長區間產生一造成與高分子主結構上有載子轉移作用，因而有很強的近紫外光波長的吸收特性。藉由此一特性，我們將此一系列高分子摻入有機太陽能電池主動層內作為第三成分的活性施子體，並成功分別於富勒烯/非富勒烯體系的有機太陽能電池中提升7.58%與/6.6%的光轉換效率於富勒烯/非富勒烯體系的有機太陽能電池。 有鑒於龐大的噻吩側鏈造成近紫外光高吸收特性，我們更進一步設計具有施體與受體的八噻吩共聚物以便提升其高分子的載子移動率，並在鈣鈦礦太陽能電池中作為電洞傳輸層與紫外光過濾層。在鈣鈦礦太陽能電池中，具有最高載子移動率的八噻吩共軛性高分子作為電洞傳輸層下，能有效提升電池於紫外光下之穩定性且得到最高轉換效率18.34%。本研究中，不僅成功提升有機與鈣鈦礦太陽能電池的表現，也同時仔細針對共軛性高分子的光電特性做分析。

In recent researches of solution-processed solar cells, utilization of conjugated polymers owning intense ultra-violet (UV) spectrum absorption are rarely studied while the UV light-harvesting is not fully still weakharvested in OPVs and it should be filtered for perovskite solar cells (PVSCs). Herein, we have developed wide band-gap (Eg) polymers based on biaxially-extended octithiophene-based conjugated structures. Owing to the π-π* transition of the conjugated biaxially-extended side-chains, such polymers exhibit intense absorption in the near-ultraviolet region in addition to the original intra-charge transfer (ICT) feature arising from the main backbone. ByThe rationally tailoring the backbone structures 8T-based polymers, they can deliver 7.58%- and 6.60% -enhancement ind PCEs for the representative fullerene-/non-fullerene-based BHJ OPVs, respectively. Thanks to the bearing bulky side-chain group of these 8T-base polymers, such 8T-based polymersthey provided complementary intense UV absorption and canin OPVs while D-A 8T-based copolymers functioned as a UV-filtering layer in the PVSCs. In view of this, we demonstrated that such 8T-based polymers can not only serve as an active third component to the binary bulk-heterojunction systems (BHJs) in OPVs Hence, we further explored the function of such polymers but alsoin serveing as an HTL in PVSCs to filter the UV-radiation. We firstWe introducede isoindigo moietyes into the polymer backbone to prepare with thiophene in backbone which is a D-A type copolymers with higherimproved mobility than original 8T-based polymers. Finally, Thanks to the bearing bulky side-chain group of these 8T-base polymers, such 8T-based polymers provided complementary intense UV absorption in OPVs while D-A 8T-based copolymers functioned as a UV-filtering layer in the PVSCs. While a high-performance (PCE: 18.34%) PVSC were realized along with a much improved UV-photostability was realized while using the highest charge mobility of 8T-based polymer as the HTL. In this thesis, we have successfully employed novel biaxially-extended octithiophene-based conjugated polymers as a third active component to developed high- performance OPVssolar cells and as HTL to realize efficient and high UV-stableresistant ability in perovskite solar cells ( PVSCs) by using a novel structural design, biaxially-extended octithiophene-based conjugated polymers as third component and hole-transporting layer (HTL) in organic photovoltaic (OPVs) and PVSCs respectively.