Mollinger Sonya A, Krajina Brad A, Noriega Rodrigo, Salleo Alberto, Spakowitz Andrew J
Department of Chemistry, University of California at Berkeley, Berkeley, California, United States.
ACS Macro Lett. 2015 Jul 21;4(7):708-712. doi: 10.1021/acsmacrolett.5b00314. Epub 2015 Jun 22.
Semiconducting polymers play an important role in a wide range of optical and electronic material applications. It is widely accepted that the polymer ordering impacts charge transport in such devices. However, the connection between molecular ordering and device performance is difficult to predict due to the current need for a mathematical theory of the physics that dictate charge transport in semiconducting polymers. We present an analytical and computational description of semicrystalline conjugated polymer materials that captures the impact of polymer conformation on charge transport in heterogeneous thin films. We first develop an analytical theory for the statistical behavior of a polymer chain emanating from a crystallite, predicting the average distance to the first kink that would trap a charge. This analysis is used to define the conditions where percolation would lead to efficient transport through a semicrystalline material. We then establish a model that predicts the multiscale charge transport. This model is used to identify the speed limits of charge transport at short and long time scales for varying fraction of crystallinity. This work provides a rational framework to connect molecular organization to device performance.
半导体聚合物在广泛的光学和电子材料应用中发挥着重要作用。人们普遍认为，聚合物的有序性会影响此类器件中的电荷传输。然而，由于目前需要一种描述半导体聚合物中电荷传输的物理数学理论，分子有序性与器件性能之间的联系很难预测。我们给出了半结晶共轭聚合物材料的分析和计算描述，该描述捕捉了聚合物构象对异质薄膜中电荷传输的影响。我们首先针对从微晶发出的聚合物链的统计行为建立了一种分析理论，预测了电荷被俘获的第一个弯折点的平均距离。该分析用于定义渗流导致通过半结晶材料进行有效传输的条件。然后我们建立了一个预测多尺度电荷传输的模型。该模型用于确定不同结晶度分数下短时间和长时间尺度上电荷传输的速度限制。这项工作提供了一个将分子组织与器件性能联系起来的合理框架。
