藉由即時電化學的摻雜在主動層以提昇高分子太陽能電池的效率

Abstract

在這項研究中，我們發現藉由即時電化學摻雜的方式形成p-i-n接面是一種有效且可行的方法，可以提高太陽能電池的性能。我們將三氟甲磺酸金屬[LiCF3SO3, KCF3SO3, Ca(CF3SO3)2, Zn(CF3SO3)2] /PEO加入MEH-PPV/PCBM混合的主動層的光伏元件中，並施加偏壓以形成p-i-n接面。 Auger元素成份縱深分佈分析及交流式電容分析法顯示了經由摻雜的元件，在大約100nm的薄膜中，其正離子和負離子因分佈不均而形成一種非對稱結構，且在較高的偏壓下，其本質層(intrinsic layer)會變得較薄。原子力顯微鏡(AFM)和穿透式電子顯微鏡(TEM)顯示加了三氟甲磺酸金屬/PEO在MEH-PPV/PCBM會改善此複合薄膜的形態。在各種不同的摻雜的元件中，LiCF3SO3/PEO加入MEH-PPV/PCBM的混合物具有最高的功率轉換效率，相對於參照的（MEH-PPV/PCBM）元件而言，其功率轉換效率增加了40％。

In this study, we found that the formation of p–i–n junction through in situ electrochemical doping is a promising way to enhance the performance of polymer photovoltaic devices. We applied a pre-bias to metal triflate [LiCF3SO3, KCF3SO3, Ca(CF3SO3)2, Zn(CF3SO3)2] /poly (PEO)–incorporated poly (MEH-PPV)/(PCBM) photovoltaic devices to form p–i–n junctions in their active layers. Auger depth profile analyses and Alternating-current capacitance analyses of these doped devices revealed that the positive and negative ions distributed unequally to form an asymmetrical p-i-n structure in a thin layer of c.a. 100nm and the intrinsic layer became thinner when formed under a higher pre-bias voltage, respectively. Atomic force microscopy and transmission electron microscopy revealed that the addition of metal triflate/PEO to MEH-PPV/PCBM improved the morphology of the composite films. Among the various doped devices, the MEH-PPV/PCBM device incorporating a LiOTf/PEO mixture exhibited the highest power conversion efficiency, a 40% increase relative to that of the reference device (MEH-PPV/PCBM).