Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.
ACS Appl Mater Interfaces. 2013 Jun 12;5(11):4617-24. doi: 10.1021/am400566f. Epub 2013 May 16.
Active layer nanomorphology is a major factor that determines the efficiency of bulk heterojunction polymer solar cells (PSCs). Synthesizing diblock copolymers in which acceptor and donor materials are the constituent blocks is the most recent method to control the structure of the active layer. In the current work, a computational method is proposed to predict the nanomorphology of the active layer consisting of a diblock copolymer. Diblock copolymers have a tendency to self-organize and form well-defined nanostructures. The shape of the structure depends on the Flory-Huggins interaction parameter (i.e., χ), the total degree of polymerization (N) and volume fractions of the constituent blocks (φi). In this work, molecular dynamics (MD) simulations were used to calculate χ parameters for two different block copolymers used in PSCs: P3HT-b-poly(S8A2)-C60 and P3HT-b-poly(n-butyl acrylate-stat-acrylate perylene) also known as P3HT-b-PPerAcr. Such calculations indicated strong segregation of blocks into cylindrical structure for P3HT-b-poly(S8A2)-C60 and intermediate segregation into cylindrical structure for P3HT-b-PPerAcr. Experimental results of P3HT-b-poly(S8A2)-C60 and P3HT-b-PTP4AP, a diblock copolymer having very similar structure to P3HT-b-PPerAcr, validate our predictions.
活性层纳米形态是决定体异质结聚合物太阳能电池 (PSC) 效率的主要因素。合成嵌段共聚物，其中给体和受体材料是组成嵌段，是控制活性层结构的最新方法。在目前的工作中，提出了一种计算方法来预测由嵌段共聚物组成的活性层的纳米形态。嵌段共聚物有自组织并形成明确定义的纳米结构的趋势。结构的形状取决于 Flory-Huggins 相互作用参数（即 χ）、总聚合度（N）和组成嵌段的体积分数（φi）。在这项工作中，使用分子动力学 (MD) 模拟计算了用于 PSC 的两种不同嵌段共聚物的 χ 参数：P3HT-b-poly(S8A2)-C60 和 P3HT-b-poly(n-丁基丙烯酰胺-丙烯酸酯对苯二甲酸酯)，也称为 P3HT-b-PPerAcr。这种计算表明，P3HT-b-poly(S8A2)-C60 中嵌段强烈分离成圆柱状结构，而 P3HT-b-PPerAcr 中嵌段则呈中间分离成圆柱状结构。与 P3HT-b-PPerAcr 结构非常相似的 P3HT-b-PTP4AP 嵌段共聚物的 P3HT-b-poly(S8A2)-C60 和 P3HT-b-PTP4AP 的实验结果验证了我们的预测。
