Organic Nanophotonics: Self-Assembled Single-Crystalline Homo-/Heterostructures for Optical Waveguides

Homo-/heterostructures are of essential importance for the multiple input/output and the wavelength division multiplexing system in optoelectronic circuits. However, the widely used preparation method, e.g., micromanipulation, usually leads to simple and unstable physical contact. Herein, through a "bottom-up" approach, we have successfully fabricated an organic homo-/heterostructures based on the 2,2′-((1E,1′E)-1,4- phenylenebis(ethene-2,1-diyl))dibenzonitrile and perylene single crystals, whose formation can be attributed to the low interplanar spacing mismatch rates, which are 2.2% for the homostructure and 4.1% for the heterostructure. More importantly, the multiple input/output channels have been demonstrated in the photonic devices based on the homo-/heterostructures, which also exhibit the novel asymmetric waveguide mode in the homostructure and the switchable transmission signals (green or yellow light) at the same output channel in the heterostructure. Our work exhibits the high potential of the novel organic homo/heterostructures being applied in multifunctional organic integrated photonics circuits at the nanoscale.