Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, P. R. China.
Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
Adv Mater. 2019 Feb;31(8):e1806016. doi: 10.1002/adma.201806016. Epub 2019 Jan 7.
Orientation control of ordered materials would not only produce new physical phenomenon but also facilitate the development of fancy devices. Discotic liquid crystals (DLCs) form 1D charge transport pathway by self-organizing into columnar nanostructures via π-π stacking. However, controlling the electrical properties in such nanostructures with some direct and instant way is a formidable task for their high viscosity and insensitivity to external stimuli. Herein, the arbitrary control over electrical conductivity of such columnar nanostructures is achieved with UV light by incorporating DLCs with molecular motors. Highly ordered DLC microstripe arrays are generated on desired substrate through a capillary bridge dewetting strategy. The conductivity of the microstripes could be continuously modulated by 365 nm light due to the influence of molecular motion under UV irradiation on the electron orbital overlap of columnar nanostructures. This is so because the disorder degree of the DLC molecules is associated with the intensity of UV light and the doping concentration of molecular motors. Moreover, the device shows memory effect and reversible conductivity change. The DLC microstripe arrays are very promising for the applications in UV detectors, memory devices, optical switches, and so on.
取向有序材料不仅会产生新的物理现象，还有助于开发奇特的器件。盘状液晶（DLC）通过π-π 堆积自组装成柱状纳米结构，形成一维电荷输运途径。然而，由于其高粘度和对外界刺激不敏感，用一些直接和即时的方法来控制这种纳米结构中的电性能是一项艰巨的任务。在此，通过将 DLC 与分子马达结合，利用 UV 光实现了对这种柱状纳米结构的任意电导率控制。通过毛细桥去湿策略，在所需的衬底上生成高度有序的 DLC 微条纹阵列。由于在 UV 照射下分子运动对柱状纳米结构的电子轨道重叠的影响，微条纹的电导率可以通过 365nm 光连续调节。这是因为 DLC 分子的无序程度与 UV 光的强度和分子马达的掺杂浓度有关。此外，该器件还表现出记忆效应和可逆的电导率变化。DLC 微条纹阵列在紫外探测器、存储器件、光开关等方面有很好的应用前景。
