The supramolecular nanofibers were prepared by mixing (R)-1NDI in the presence of 1.5 mol% 10 -7 M), followed by drop casting onto an untreated glass slide. Upon selective excitation of (R)-1NDI at 445 nm, the emission spectrum showed a low-intensity emission band at 480 nm corresponding to the diethoxy-NDI unit and a major emission band peaking at 540 nm of the (S)-2PDI unit (Figure ). This indicates efficient light-harvesting from (R)-1NDI nanofibers to the (S)-2PDI molecule. This light-harvesting behavior was evaluated by monitoring the relative emission intensities of (S)-2PDI at 540 nm and (R)-1NDI at 480 nm (I540/I480), which was approximately 6-fold when deposited on the untreated glass surface. This value is significantly lower than in the bulk solution phase (~20 fold). This efficient light-harvesting phenomenon is specific for the combination [(R)-1NDI nanofibers+(S)-2PDI] and [(S)-1NDI nanofibers+(R)-2 PDI], but not those of same chirality. The sample deposited on a plasma-treated glass slide showed a significantly lower I540/I480 value (ca. 4 fold) along with a broad band above 580 nm.