Showing papers by "Jiangang Feng published in 2015"

Positioning and joining of organic single-crystalline wires

Abstract: Organic single-crystal, one-dimensional materials can effectively carry charges and/or excitons due to their highly ordered molecule packing, minimized defects and eliminated grain boundaries. Controlling the alignment/position of organic single-crystal one-dimensional architectures would allow on-demand photon/electron transport, which is a prerequisite in waveguides and other optoelectronic applications. Here we report a guided physical vapour transport technique to control the growth, alignment and positioning of organic single-crystal wires with the guidance of pillar-structured substrates. Submicrometre-wide, hundreds of micrometres long, highly aligned, organic single-crystal wire arrays are generated. Furthermore, these organic single-crystal wires can be joined within controlled angles by varying the pillar geometries. Owing to the controllable growth of organic single-crystal one-dimensional architectures, we can present proof-of-principle demonstrations utilizing joined wires to allow optical waveguide through small radii of curvature (internal angles of similar to 90-120 degrees). Our methodology may open a route to control the growth of organic single-crystal one-dimensional materials with potential applications in optoelectronics.

Large‐Scale Assembly of Organic Highly Crystalline Multicomponent Wires through Surface‐Engineered Condensation and Crystallization

Abstract: Highly crystalline multicomponent wire arrays are fabricated by a scalable technique, termed surface-engineered condensation and crystallization (SECC). Alignment and position are precisely controlled with the guidance of a micropillar-structured substrate with regionally different wettability and vapor-flow controllability.