Imaging Science and Engineering Research Center, Tokyo Institute of Technology, 4259-J1-2 Nagatsuta Midori-ku, Yokohama 226-8503, Japan.
Soft Matter. 2017 Sep 27;13(37):6499-6505. doi: 10.1039/c7sm01303e.
Fabrication of planarly-oriented polycrystalline thin films of organic semiconductors was investigated, in which molecules sit parallel, i.e., "face-on" on the substrate so as to allow vertical charge transport favorably through a thin film. With the aid of self-organization of liquid crystalline molecules and an over-coated orientation layer, tens of nm thin films vertically oriented can be re-oriented from "hemeotropic, or vertical" to "homogenous or planar" to achieve polycrystalline thin films planarly oriented after removing the over-coated orientation layer. We investigated the key factors to affect re-orientation of the films and uniformity and surface morphology of the resulting films, including conditions required for the re-orientation and properties of the orientation layer materials and liquid crystals.
我们研究了平面取向的有机半导体多晶薄膜的制备，其中分子平行于基底排列，即“面内”，以有利于通过薄膜进行垂直电荷输运。借助液晶分子的自组织和覆盖的取向层，可以将数十纳米厚的薄膜从“向列型，即垂直”重新取向为“各向同性或平面”，以在去除覆盖的取向层后获得平面取向的多晶薄膜。我们研究了影响薄膜重取向和所得薄膜均匀性和表面形貌的关键因素，包括重取向所需的条件以及取向层材料和液晶的性质。
