Organic Functional Molecule-Based Single-Crystalline Nanowires for Optical Waveguides and Their Patterned Crystals

The deterministic manufacturing and patterning of high-quality organic single crystal semiconductors are core opportunities and challenges for large-scale integrated functional devices with high efficiency and high performance. As for the solution patterning for the fabrication of the organic semiconductors, various methods are reported to efficiently control the position, alignment, and size of organic structures. Nevertheless, the poor control of the dewetting dynamics of organic solution leads to the low crystallinity and disordered crystallographic orientation of as-fabricated organic architectures, which can limit their device performance. Herein, by use of the micropillar-structured template with asymmetric wettability, the patterned organic 1D single crystals with precise position and geometry, flat morphology, and high alignment can be constructed. Moreover, the nanowire arrays are demonstrated with active optical waveguiding. In addition, the other patterned architectures of circle, triangle, square, pentagon, and hexagon shapes can also be constituted by regulating the surface geometry of substrates. This work not only facilitates the fundamental understanding on the patterning and crystallization of organic architectures, but also contributes greatly to the development of large-scale assembly technology for patterning micro/nanostructures.