A strong regioregularity effect in self-organizing conjugated polymer films and high-efficiency polythiophene: fullerene solar cells
A strong regioregularity effect in self-organizing conjugated polymer films and high-efficiency polythiophene: fullerene solar cells
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DOI：
10.1038/nmat1574
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发表时间：
2006-03-01
期刊：
影响因子：
41.2
通讯作者：
Ree, M
中科院分区：
文献类型：
--
作者：
Kim, Y;Cook, S;Ree, M
通过有机“体异质结（BHJ）”结构的发展，使用共轭分子材料的低成本光伏能量转换变得越来越可行（1-7），其中通过大面积的供体-受体界面实现了有效的光诱导电荷分离（2,3）。使用聚（3-己基噻吩）（P3HT）和富勒烯衍生物（8-12）的共混物实现了最高的效率，但性能主要取决于材料特性和加工条件。这种可变性被认为是受P3HT的自组织特性的影响，这意味着光学（13,14）和电子（15,16）特性都对分子填充敏感。然而，共混材料的分子纳米结构、光电性能与器件性能之间的关系尚未得到证实。在这里，我们重点研究了聚合物区域规则性（RR）对分子纳米结构的影响，从而对所得到的材料性能和器件性能的影响。我们发现RR对太阳能电池性能有很强的影响，这可以归因于P3HT链和结构域的组织导致的光吸收和传输增强。进一步优化使用最高RR材料的器件，即使没有优化电极，功率转换效率也达到4.4%(7)。
Low-cost photovoltaic energy conversion using conjugated molecular materials has become increasingly feasible through the development of organic 'bulk heterojunction (BHJ)' structures(1-7), where efficient light-induced charge separation is enabled by a large-area donor - acceptor interface(2,3). The highest efficiencies have been achieved using blends of poly(3-hexylthiophene) (P3HT) and a fullerene derivative(8-12), but performance depends critically on the material properties and processing conditions. This variability is believed to be influenced by the self-organizing properties of P3HT, which means that both optical(13,14) and electronic(15,16) properties are sensitive to the molecular packing. However, the relationship between molecular nanostructure, optoelectronic properties of the blend material and device performance has not yet been demonstrated. Here we focus on the influence of polymer regioregularity (RR) on the molecular nanostructure, and hence on the resulting material properties and device performance. We find a strong influence of RR on solar-cell performance, which can be attributed to enhanced optical absorption and transport resulting from the organization of P3HT chains and domains. Further optimization of devices using the highest RR material resulted in a power conversion efficiency of 4.4%, even without optimization of electrodes(7).