During last decade, we have explored unique photophysical properties of structurally floppy α-cyanostilbene compounds. It was found that α-cyanostilbene is an outstanding supramolecular self-assembly motif to give characteristic nanostructures of varying dimensionality. Most peculiarly, self-assembly of this structural motif is accompanied by the significant fluorescence modulation and enhanced charge transport properties. By rational molecular design, high performance n-type organic semiconductor and non-fullerene solar cell acceptor have successfully been synthesized and characterized.