Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States.
J Am Chem Soc. 2012 Mar 28;134(12):5436-9. doi: 10.1021/ja2116316. Epub 2012 Feb 8.
Due to the rapidity of morphological development during deposition, solution-processed organic semiconductor thin films exist in semicrystalline or polycrystalline states, incorporating a high degree of local variations in molecular orientation compared to their single-crystal counterparts. Spherulites, a common crystalline superstructure found in these systems, for example, incorporate a large distribution of molecular orientations about the radial axis to maintain their space-filling growth habit. Here, we aim to determine how this distribution of molecular orientations influences charge transport by fabricating arrays of devices on single spherulites. Given that the orientation distribution that is present about the radial axis mandates the presence of low-angle grain boundaries within single spherulites, we find intraspherulitic charge transport to be independent of the general direction of π-stacking; organic field-effect transistors exhibit comparable mobilities regardless of how their channels are oriented with respect to the general π-stacking direction.
由于在沉积过程中形态发育迅速，溶液处理的有机半导体薄膜存在于半晶态或多晶态，与单晶相比，其分子取向具有高度的局部变化。例如，在这些体系中常见的晶体超结构球晶，为了保持其空间填充生长习性，在径向轴周围包含了大量的分子取向分布。在这里，我们旨在通过在单个球晶上制造器件阵列来确定这种分子取向分布如何影响电荷输运。鉴于关于径向轴的取向分布要求在单个球晶内存在低角度晶界，我们发现球内电荷输运与π-堆积的一般方向无关;有机场效应晶体管表现出可比较的迁移率，无论它们的沟道相对于一般的π-堆积方向如何取向。
