Design of asymmetric benzodithiophene based wide band-gap conjugated polymers toward efficient polymer solar cells promoted by a low boiling point additive
Design of asymmetric benzodithiophene based wide band-gap conjugated polymers toward efficient polymer solar cells promoted by a low boiling point additive
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低沸点添加剂促进的高效聚合物太阳能电池的不对称苯并二噻吩基宽带隙共轭聚合物的设计
DOI：
10.1039/c8tc00148k
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发表时间：
2018-03-21
影响因子：
6.4
通讯作者：
Yang, Renqiang
中科院分区：
文献类型：
--
作者：
Li, Yonghai;Duan, Linrui;Yang, Renqiang
在这项工作中，我们报告了两个宽带隙的给体-受体（D-A）光伏材料的基础上不对称苯并二噻吩单元与裸露的苯基或烷氧基链修饰的苯基作为取代基之一。这两种聚合物的光学带隙均在1.80 eV以上。P2（在苯基基团中具有侧链）与连接有裸苯基基团的聚合物P1相比显示出略微红移的膜吸收光谱，这部分归因于更好的分子构象和分子间相互作用。制备了具有不同受体材料的聚合物太阳能电池，以系统地评估两种聚合物的光伏性能。结果表明，与P1相比，P2基富勒烯和无富勒烯太阳能电池均表现出上级的光伏性能，这主要归因于更好的异质结形貌和更平衡的电荷输运。与P1的效率（7.04%）相比，以PC 71 BM作为受体的基于P2的PSC表现出增强的效率（8.58%）。值得注意的是，低沸点甲苯首次被报道为优化无富勒烯聚合物太阳能电池光伏性能的有效添加剂。基于P2/ITIC的器件的最佳效率达到9%以上，V-OC为0.90 V，J（SC）为16.70 mA cm（-2），FF为0.603，表明低沸点溶剂作为高效无富勒烯聚合物太阳能电池的添加剂的巨大潜力。
In this work, we reported two wide band-gap donor-acceptor (D-A) photovoltaic materials based on asymmetric benzodithiophene units with a bare phenyl or alkoxyl chain modified phenyl group as one of the substitutions. The optical band-gaps of the two polymers are both identified above 1.80 eV. P2 (with a side chain in the phenyl group) reveals slightly red-shifted film absorption spectra compared to polymer P1 attached with the bare phenyl group, which is partly attributed to the better molecular conformations and intermolecular interactions. Polymer solar cells with different acceptor materials are fabricated to systematically evaluate the photovoltaic properties of the two polymers. The results show that P2 based fullerene and fullerene-free solar cells both show superior photovoltaic performance over the devices of P1, mainly attributed to the more favorable heterojunction morphologies and more balanced charge transport. P2 based PSCs with PC71BM as the acceptor demonstrate an enhanced efficiency (8.58%) compared to that of P1 (7.04%). Notably, low boiling point toluene was reported as an effective additive for the first time to optimize the photovoltaic performance of fullerene-free polymer solar cells. The best efficiency of the P2/ITIC based devices reached over 9%, with a V-OC of 0.90 V, J(SC) of 16.70 mA cm(-2), and FF of 0.603, suggesting the great potential of low boiling point solvents as the additive toward efficient fullerene-free polymer solar cells.