Charge Photogeneration for a Series of Thiazolo‐Thiazole Donor Polymers Blended with the Fullerene Electron Acceptors PCBM and ICBA
Charge Photogeneration for a Series of Thiazolo‐Thiazole Donor Polymers Blended with the Fullerene Electron Acceptors PCBM and ICBA
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DOI：
10.1002/adfm.201203148
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发表时间：
2013-07
影响因子：
19
通讯作者：
S. Shoaee;Selvam Subramaniyan;H. Xin;Chaz Keiderling;P. S. Tuladhar;Fiona C. Jamieson;S. Jenekhe
中科院分区：
文献类型：
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作者：
S. Shoaee;Selvam Subramaniyan;H. Xin;Chaz Keiderling;P. S. Tuladhar;Fiona C. Jamieson;S. Jenekhe
研究了体异质结太阳能电池中的光诱导电荷分离，使用一系列噻唑并噻唑供体聚合物，其侧基（和桥接原子）与两种受体富勒烯，苯基-C71-丁酸甲酯（PC 71 BM）和富勒烯茚-C60双加合物（ICBA）共混。瞬态吸收光谱用于确定光生电荷载流子的产率和寿命，并辅以材料能量学的循环伏安法研究、纯膜和共混膜结晶度的广角X射线衍射和透射电子显微镜研究以及聚合物/富勒烯相分离的光致发光猝灭研究，以及这些测量与器件光电流的相关性。初始极化子产额与驱动电荷分离的能量驱动力ΔECS之间存在良好的相关性。所有共混物膜均表现出分配给解离电荷的非成对复合的幂律瞬态吸收衰减阶段;该幂律衰减阶段的振幅显示出与器件中的光电流密度的良好相关性。此外，对于一个（相对无定形）施主聚合物与ICBA共混的膜，我们观察到一个额外的100 ns的孪晶复合相。所报道的意见的影响进行了讨论，在影响电荷解离在这样的设备中的材料的结晶度的作用，从而有效的太阳能电池功能的材料设计要求。
Photoinduced charge separation in bulk heterojunction solar cells is studied using a series of thiazolo‐thiazole donor polymers that differ in their side groups (and bridging atoms) blended with two acceptor fullerenes, phenyl‐C71‐butyric acid methyl ester (PC71BM) and a fullerene indene‐C60 bisadduct (ICBA). Transient absorption spectroscopy is used to determine the yields and lifetimes of photogenerated charge carriers, complimented by cyclic voltammetry studies of materials energetics, wide angle X‐ray diffraction and transmission electron microscopy studies of neat and blend film crystallinity and photoluminescence quenching studies of polymer/fullerene phase segregation, and the correlation of these measurements with device photocurrents. Good correlation between the initial polaron yield and the energetic driving force driving charge separation, ΔECS is observed. All blend films exhibit a power law transient absorption decay phase assigned to non‐geminate recombination of dissociated charges; the amplitude of this power law decay phase shows excellent correlation with photocurrent density in the devices. Furthermore, for films of one (relatively amorphous) donor polymer blended with ICBA, we observe an additional 100 ns geminate recombination phase. The implications of the observations reported are discussed in terms of the role of materials' crystallinity in influencing charge dissociation in such devices, and thus materials design requirements for efficient solar cell function.