有機太陽能電池之介面與表面形態工程

Interface and Morphology Engineering for Organic Photovoltaics

林倞(Ching Lin)

指導教授 ： 蔡豐羽

國立臺灣大學/工學院/材料科學與工程學研究所/博士(2010年)

https://doi.org/10.6342/NTU.2010.02530

摘要

在此研究中，我們致力於解決有機太陽能電池的重要議題；我們的貢獻包括 (1) 提升高分子太陽能電池的穩定性和效率，及(2) 降低染料敏化電池中的電荷再結合率與提升其電荷傳遞效能。我們提出並驗證了，-5 oC低溫乾燥接著熱退火可提升以3甲基嘧啶與富勒烯衍生物的混合層製成的高分子電池中3甲基嘧啶與富勒烯衍生物的介面數量，進而達成高的電池效率；同時因為促使3甲基嘧啶高度結晶，其結晶阻礙了富勒烯衍生物與3甲基嘧啶之間的相分離，而提升了電池的穩定度。延伸應用方面，我們刻意模擬了高分子電池混合層因不適當的溶劑所造成成膜失敗而降低電池效率；經由上述低溫乾燥接著熱退火的技術，我們大大改善了其成膜性與電池效率。對染料敏化電池的貢獻方面，針對以多孔二氧化鈦上鍵結染料所製成的電池，我們利用原子層沈積技術在其多孔二氧化鈦上生成厚度為一埃的高能隙氧化鋁，成功阻擋了二氧化鈦與染料或與電解質之間的電荷再結合；另一方面，我們利用原子層沈積技術在電池的多孔二氧化鈦上生成高純度銳鈦礦，提升其電池的電子傳遞能力。

關鍵字

太陽能電池 ； 有機電子元件 ； 高分子 ； 奈米結構 ； 原子層沈積

並列摘要

In this study, we conducted multipronged research to address the key issues of organic solar cells; our accomplishments include (1) improved efficiency and stability of polymer solar cell (PSC) by developing a novel low-temperature film-forming process which can be used with halogen-less solvents, and (2) reduced charge recombination and enhanced charge transport in dye-sensitized solar cell (DSSC) by developing interface-modifying thin films formed by low-temperature atomic layer deposition processes. In our PSC work, we demonstrated a film-forming process invloving low-temperature drying (-5 oC) and subsequent annealing for the active layer composed of blended poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM). The low-temperature process enhanced nucleation of P3HT crystals, producing ample PCBM/P3HT bulk-heterojunction area to improve the efficiency, and forming a P3HT crystal network which served as an immobile frame to prevent PCBM/P3HT phase separation and the corresponding device degradation. Moreover, the low-temperature process could be used with a halogen-less solvent, tetralin, to obtain PSCs with similar device performance as that with the typical halogen-containing solvents. In our DSSC work, we demonstrated significant reduction in charge recombination with a 1 A Al2O3 formed with atomic layer deposition (ALD) on the porous TiO2 electrode, and correlated the improvement to the increase in Fermi level caused by the ALD film. Additionally, we improved the efficiency of DSSCs made with low-temperature sintering by ~70% by overcoating the porous TiO2 electrode with a 2 nm TiO2 film grown by ALD, which had significantly higher electron mobility than the porous TiO2 electrode.

並列關鍵字

Photovoltaic Devices ； Conjugated Polymers ； Organic Electronics ； Solar Cells ； Nanostructures ； Atomic Layer Deposition (ALD)

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