Electro-optical switching of graphene oxide liquid crystals with an extremely large Kerr coefficient
Electro-optical switching of graphene oxide liquid crystals with an extremely large Kerr coefficient
复制标题
DOI：
10.1038/nmat3888
复制
发表时间：
2014-04-01
期刊：
影响因子：
41.2
通讯作者：
Song, Jang-Kun
中科院分区：
文献类型：
--
作者：
Shen, Tian-Zi;Hong, Seung-Ho;Song, Jang-Kun
向列相氧化石墨烯（GO）相对外部刺激的敏感响应使得该相对于扩展氧化石墨烯和还原氧化石墨烯在溶液工艺和电光器件中的适用性具有吸引力。然而，与预期相反，向列氧化石墨烯的排列很难通过应用电场或表面处理来控制。本研究表明，当片间相互作用足够弱时，氧化石墨烯液晶（LCs）的微观有序程度和宏观排列方向都可以通过施加低电场来控制。我们还表明，氧化石墨烯和Onsager排除体积效应的大极化各向异性共同产生的Kerr系数比迄今为止在分子lc中获得的最大值大3个数量级。极大的克尔系数使我们能够制造具有宏观电极的电光器件，以及在宽区域内排列良好、无缺陷的氧化石墨烯。
The sensitive response of the nematic graphene oxide (GO) phase to external stimuli makes this phase attractive for extending the applicability of GO and reduced GO to solution processes and electro-optic devices. However, contrary to expectations, the alignment of nematic GO has been difficult to control through the application of electric fields or surface treatments. Here, we show that when interflake interactions are sufficiently weak, both the degree of microscopic ordering and the direction of macroscopic alignment of GO liquid crystals (LCs) can be readily controlled by applying low electric fields. We also show that the large polarizability anisotropy of GO and Onsager excluded-volume effect cooperatively give rise to Kerr coefficients that are about three orders of magnitude larger than the maximum value obtained so far in molecular LCs. The extremely large Kerr coefficient allowed us to fabricate electro-optic devices with macroscopic electrodes, as well as well-aligned, defect-free GO over wide areas.