Morphology Related Photodegradation of Low‐Band‐Gap Polymer Blends
Morphology Related Photodegradation of Low‐Band‐Gap Polymer Blends
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DOI：
10.1002/aenm.201400497
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发表时间：
2014-12
影响因子：
27.8
通讯作者：
Xiao Wang;H. Egelhaaf;H. Mack;H. Azimi;C. Brabec;A. Meixner;Dai Zhang
中科院分区：
文献类型：
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作者：
Xiao Wang;H. Egelhaaf;H. Mack;H. Azimi;C. Brabec;A. Meixner;Dai Zhang
利用光学显微镜和扫描探针显微镜研究了低禁带聚合物共混物的形态相关光降解。Poly[2，6‐(4，4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2，1‐b；研究了3，4‐b′]dithiophene)‐alt‐4，7(2，1，3‐benzothiadiazole)](C-PCPDTBT)：[6，6]-苯基C61-丁酸甲酯共混膜以及poly[(4，40‐bis(2‐ethylhexyl)dithieno[3，2‐b:20，30‐d]silole)‐2，6‐diylalt‐(2，1，3‐benzothiadiazole)‐4，7‐diyl](Si-PCPDTBT)：PCBM共混膜在有无惰性气体保护和有无惰性气体保护的环境条件下的激光辐照性能。聚合物的光降解开始于PCBM分子附近(第一球降解)，这有效地阻止了电子转移过程。在C-PCPDTBT：PCBM/ODT共混物中观察到Stern-Volmer动力学，表明只有少量的光氧化单体单元对C-PCPDTBT聚合物的发光起到猝灭作用。此外，除了聚合物分子的永久性损伤外，从其拉曼强度的下降可以看出，当恢复惰性气体保护时，聚合物的光致发光表现出部分可逆的恢复，这表明临时的聚合物/O2-电荷转移络合物参与了光降解过程。
The morphology related photodegradation of low band‐gap polymer blends is investigated using optical microscopy and scanning probe microscopy. Poly[2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7(2,1,3‐benzothiadiazole)] (C‐PCPDTBT):[6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) blend films without and with ODT, as well as poly[(4,40‐bis(2‐ethylhexyl)dithieno[3,2‐b:20,30‐d]silole)‐2,6‐diylalt‐(2,1,3‐benzothiadiazole)‐4,7‐diyl] (Si‐PCPDTBT):PCBM blend films exposed to a focused 632.8 nm laser under ambient condition with and without inert gas protection are studied. The photodegradation of the polymer starts in the vicinity of the PCBM molecules (first sphere degradation), which effectively blocks the electron transfer processes. Stern‐Volmer type kinetics are observed in the C‐PCPDTBT:PCBM blend with ODT, which indicates that only a small number of photo‐oxidized monomer units act as quenchers of the C‐PCPDTBT polymer luminescence. Furthermore, in addition to the permanent damage of the polymer molecules, as witnessed from their Raman intensity decrease, the polymer photoluminescence demonstrates partial reversible recovery when inert gas protection is resumed, indicating the involvement of temporary polymer/O2‐charge transfer complexes in the photodegradation process.