Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA.
Soft Matter. 2017 Apr 12;13(15):2773-2780. doi: 10.1039/c6sm02631a.
Device efficiency in key organic electronic devices such as organic photovoltaics, field transistors, and light emitting diodes has long been known to be closely tied to the conformation of the conjugated polymer chains which make up the active layers. Our previous results show that light exposure can have a profound effect on the structure and assembly of these optoelectronic materials in solution. In order to advance our understanding of the role which solvent quality plays in this phenomenon, we have further studied the modulation of these illumination dependent structural changes on the key benchmark conjugated polymers P3HT and MEH-PPV as a function of solvent quality over a wide range of polymer solubilities. Analysis of this data indicates that use of poorer conjugated polymer solvents ultimately results in larger absolute alterations to polymer conformation, denoting the crucial role which solution thermodynamics plays in this generic effect. This discovery opens the door to controlling final device morphology through careful manipulation of solvent composition during solution based device casting techniques, moving our efforts closer to the development of a powerful, non-destructive, and tunable method for light-driven control of polymer conformation in novel light-responsive organic materials.
器件效率在一些关键的有机电子设备中，如有机光伏、场效应晶体管和发光二极管，长期以来一直与构成活性层的共轭聚合物链的构象密切相关。我们之前的研究结果表明，光照可以对这些光电材料在溶液中的结构和组装产生深远的影响。为了深入了解溶剂质量在这一现象中所起的作用，我们进一步研究了在很宽的聚合物溶解度范围内，溶剂质量对关键基准共轭聚合物 P3HT 和 MEH-PPV 的这些光照依赖性结构变化的调制作用。对这些数据的分析表明，使用较差的共轭聚合物溶剂最终会导致聚合物构象发生更大的绝对变化，这表明溶液热力学在这一普遍效应中起着至关重要的作用。这一发现为通过在基于溶液的器件铸造技术中仔细控制溶剂组成来控制最终器件形态开辟了道路，使我们的努力更接近于开发一种强大、非破坏性和可调谐的方法，用于在新型光响应有机材料中光驱动控制聚合物构象。
