High-Performance Wide Bandgap Copolymers Using an EDOT Modified Benzodithiophene Donor Block with 10.11% Efficiency
High-Performance Wide Bandgap Copolymers Using an EDOT Modified Benzodithiophene Donor Block with 10.11% Efficiency
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高性能%20Wide%20Bandgap%20Copolymers%20Using%20an%20EDOT%20Modified%20Benzodithiophene%20Donor%20Block%20with%2010.11%%20效率
DOI：
10.1002/aenm.201602773
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发表时间：
2018
影响因子：
27.8
通讯作者：
Peng Qiang
中科院分区：
文献类型：
--
作者：
Feng Kui;Yang Guofang;Xu Xiaopeng;Zhang Guangjun;Yan He;Awartani Omar;Ye Long;Ade Harald;Li Ying;Peng Qiang
首次将新型苯并[1，2-B：4，5-B′]二噻吩（BDT）嵌段与3，4-亚乙基二氧噻吩（EDOT）侧链用于构建高效光伏共聚物。所得共聚物PBDTEDOT-BT和PBDTEDOTFBT具有大于1.80 eV的大带隙，这归因于BDT和EDOT骨架之间的空间位阻增加。两种共聚物均具有较好的结晶性、较低的最高占据轨道（HOMO）能级和较高的结晶度。使用这种吸收策略，PBDTEDOT-FBT比PBDTEDOT-BT表现出更宽、更强的吸收和更深的HOMO能级。与PBDTEDOTBT：PC 71 BM共混物相比，PBDTEDOT-FBT：[6，6]-苯基C71丁酸甲酯（PC 71 BM）共混物也显示出更高的空穴迁移率和更好的表面形态。结合上述优点，PBDTEDOT-FBT器件表现出更高的功率转换效率（PCE），为10.11%，开路电压（Voc）为0.86 V，短路电流密度（Jsc）为16.01 mA cm−2，填充因子（FF）为72.6%。这项工作不仅提供了一种新的有效候选的BDT供体嵌段修饰与EDOT共轭侧链，但也实现了高性能的大带隙共聚物的聚合物太阳能电池（PSC）通过协同效应的双链和侧链工程策略。
Newly developed benzo[1,2‐b:4,5‐b′]dithiophene (BDT) block with 3,4‐ethylenedioxythiophene (EDOT) side chains is first employed to build efficient photovoltaic copolymers. The resulting copolymers, PBDTEDOT‐BT and PBDTEDOTFBT, have a large bandgap more than 1.80 eV, which is attributed to the increased steric hindrance between the BDT and EDOT skeletons. Both copolymers possess the satisfied absorptions, low‐lying highest occupied molecular orbital (HOMO) levels and high crystallinity. Using the fluorination strategy, PBDTEDOT‐FBT exhibits a wider and stronger absorption and a deeper HOMO level than those of PBDTEDOT‐BT. PBDTEDOT‐FBT:[6,6]‐Phenyl C71butyric acid methyl ester (PC71BM) blend also shows the higher hole mobility and better surface morphology compared with the PBDTEDOTBT:PC71BM blend. Combination of above advantages, PBDTEDOT‐FBT devices exhibit much higher power conversion efficiency (PCE) of 10.11%, with an improved open circuit voltage (Voc) of 0.86 V, short circuit current densities (Jsc) of 16.01 mA cm−2, and fill factor (FF) of 72.6%. This work not only provides a newly efficient candidate of BDT donor block modified with EDOT conjugated side chains, but also achieves high‐performance large bandgap copolymers for polymer solar cells (PSCs) via the synergistic effect of fluorination and side chain engineering strategies.