aggregates in the vicinity of the nanofibers, resulting in unpolarized emission. The AFM images on displayed regions (I-III) in Figure ensured the reliability of the polarization studies by optical microscopy without any noticeable artifacts. Indeed, the AFM images showed well-defined straight long fibers oriented at specific angles to each other, without any break in the nanofiber networks upon coiling or branching. On the one hand, the spectra at the green-emitting regions 3, 4, and 7 (Figure , white circles), corresponding to the vertically oriented fibers (north/south) to that of the excitation polarization beam, showed an intense emission maximum centered at 540 nm with the enhanced relative fluorescence intensity (I540/I480), indicating the preferential green emission of the (S)-2PDI guest units by efficient energy transfer from the vertically oriented fibers.