Effects of Thermal Annealing Upon the Morphology of Polymer-Fullerene Blends
Effects of Thermal Annealing Upon the Morphology of Polymer-Fullerene Blends
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DOI：
10.1002/adfm.201000975
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发表时间：
2010-10-22
影响因子：
19
通讯作者：
Bao, Zhenan
中科院分区：
文献类型：
--
作者：
Verploegen, Eric;Mondal, Rajib;Bao, Zhenan
掠入射x射线散射（GIXS）用于表征聚（3-己基噻吩）(P3HT)-苯基- c61 -丁酸甲酯（PCBM）薄膜体异质结（BHJ）共混物的形貌，作为热退火温度的函数，从室温到220℃。为原位GIXS研究定制的加热室允许在高温下对薄膜进行形态表征。用热梯度退火的薄膜允许在一定温度范围内快速研究形态，从而证实原位实验的结果。使用这些技术可以观察到以下情况：每个组分的熔点；在P3HT熔化温度以下退火，P3HT相干长度增加；当熔体冷却后，形成与基体平行的（100）面取向良好的P3HT晶体；以及与PCBM玻璃化转变温度相关的PCBM冷结晶。这些材料掺入BHJ共混物会影响这些转变的性质，并与共混比成函数关系。这些结果提供了对热退火如何影响聚合物-富勒烯BHJ共混物形态的物理学更深入的理解，并提供了操纵共混物形态的工具，以开发高性能有机太阳能电池器件。
Grazing incidence X-ray scattering (GIXS) is used to characterize the morphology of poly(3-hexylthiophene) (P3HT)-phenyl-C61-butyric acid methyl ester (PCBM) thin film bulk heterojunction (BHJ) blends as a function of thermal annealing temperature, from room temperature to 220 degrees C. A custom-built heating chamber for in situ GIXS studies allows for the morphological characterization of thin films at elevated temperatures. Films annealed with a thermal gradient allow for the rapid investigation of the morphology over a range of temperatures that corroborate the results of the in situ experiments. Using these techniques the following are observed: the melting points of each component; an increase in the P3HT coherence length with annealing below the P3HT melting temperature; the formation of well-oriented P3HT crystallites with the (100) plane parallel to the substrate, when cooled from the melt; and the cold crystallization of PCBM associated with the PCBM glass transition temperature. The incorporation of these materials into BHJ blends affects the nature of these transitions as a function of blend ratio. These results provide a deeper understanding of the physics of how thermal annealing affects the morphology of polymer-fullerene BHJ blends and provides tools to manipulate the blend morphology in order to develop high-performance organic solar cell devices.