Growth of single-crystals and microstructures using benzothiadiazole derivatives for efficient optical waveguide and nonlinearity

Abstract

Organic nanomaterials have been extensively studied for the applications of the electronic and photonic fields. The bottom-up fabrication through self-assembly provides a powerful strategy to construct the nanostructures. In this work, we synthesized a conjugated molecule, namely, 4-(1-phenyl-1H-1,2,3-triazol-4-yl)benzo[c][1,2,5]thiadiazole (BT-SC), based on benzothiadiazole and benzene moieties bridged by a triazole. Then, a simple solvent-vapor annealing technique was presented to drive the self-assembly of BT-SC into highly uniform microrods or microfibers. The morphology of the self-assembly could be controlled by simply changing the solution concentration. The compound also could be assembled into aligned nanowires by wetting into hard templates of anodic aluminum oxide (AAO). The fabricated microrods showed strong emitter and excellent optical waveguide behaviors excited with a UV laser. Moreover, the microrods displayed nonlinear optical responses of two-photon excited fluorescence and could therefore become building blocks for actual photonic devices.