Recently, disordered blends of semiconducting and insulating polymers have been used to prepare light-emitting diodes with increased luminous efficiency. Because the thermodynamic stability of the disordered phase in blends is limited, equivalent diblock copolymers (BCPs) could be an alternative. However, the choice between disordered blends and BCPs requires understanding structural differences and their effect on charge carrier transport. Using a hybrid mesoscopic model, we simulate blends and equivalent BCPs of two representative semiconducting and insulating polymers: poly(p-phenylene vinylene) (PPV) and polyacrylate. The immiscibility is varied to mimic annealing at different temperatures. We find stable or metastable disordered morphologies until we reach the mean-field (MF) spinodal. Disordered morphologies are heterogeneous because of thermal fluctuations and local segregation. Near the MF spinodal, segregation is stronger in BCPs than in the blends, even though the immiscibility, normalized by the MF spinodal, is the same. We link the spatial distribution of PPV with electric conductance. We predict that the immiscibility (temperature at which the layer is annealed) affects electrical percolation much stronger in BCPs than in blends. Differences in the local structure and percolation between blends and BCPs are enhanced at a high insulator content.

中文翻译：

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用介观模拟探索发光二极管的共混物和嵌段共聚物的无序形态。

最近，半导体和绝缘聚合物的无序共混物已经用于制备具有提高的发光效率的发光二极管。由于共混物中无序相的热力学稳定性受到限制，因此可以选择等效的二嵌段共聚物（BCP）。但是，在无序共混物和BCP之间进行选择需要了解结构差异及其对电荷载流子传输的影响。使用混合介观模型，我们模拟两种代表性的半导体和绝缘聚合物的共混物和等效BCP：聚（p-亚苯基亚乙烯基）（PPV）和聚丙烯酸酯。改变不混溶性以模仿在不同温度下的退火。我们找到稳定或亚稳态的无序形态，直到到达均场（MF）旋节线。由于热波动和局部偏析，无序形态是异质的。在MF旋节线附近，即使通过MF旋节线归一化的不混溶性相同，BCP中的偏析也比共混物中的偏析强。我们将PPV的空间分布与电导率联系起来。我们预测，BCP中的不溶混性（层退火的温度）对电渗流的影响远大于掺混物。在高绝缘体含量的情况下，共混物和BCP之间的局部结构和渗透差异有所增加。