In this work, we report the aggregation-induced emission in a polymeric donor material poly(bis(2-butyloctyl)[2,2′:5′,2″-terthiophene]-4,4″-dicarboxylate-5,5′-diyl-vinylene) (PTVT-T), which exhibits a high device performance for the application of photovoltaics. Time-dependent density functional theory calculations and steady-state and time-resolved spectroscopy have been employed to reveal the underlying emission mechanism. We find that the aggregation of the PTVT-T polymer chain in solution increases the exciton luminescence lifetime and exciton emission quantum yield, which is related to the effective torsional inhibition of carbon–carbon single bonds. Compared with the aggregates in solution, the exciton emission quantum yield of the aggregates in PTVT-T film is reduced. It is attributable to exciton delocalization caused by the improvement of molecular planarity in film. We also observe that the as-cast film and thermally annealed film show distinctly different emission behaviors. This work can shed light on designing optoelectronic polymer materials with the integration of photovoltaic and light-emitting functions.

中文翻译：

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聚合光伏供体材料中的聚集诱导发射

在这项工作中，我们报告了聚合物供体材料聚（双（2-丁基辛基）[2,2':5',2”-三噻吩]-4,4”-dicarboxylate-5,5'中的聚集诱导发射-diyl-vinylene) (PTVT-T)，在光伏应用中表现出很高的器件性能。时间相关的密度泛函理论计算和稳态和时间分辨光谱已被用来揭示潜在的发射机制。我们发现 PTVT-T 聚合物链在溶液中的聚集增加了激子发光寿命和激子发射量子产率，这与碳-碳单键的有效扭转抑制有关。与溶液中的聚集体相比，PTVT-T薄膜中聚集体的激子发射量子产率降低。这归因于薄膜中分子平面性的改善引起的激子离域。我们还观察到铸态薄膜和热退火薄膜显示出明显不同的发射行为。这项工作可以为设计具有光伏和发光功能的光电聚合物材料提供启示。