Fig. 2. (a) Extinction spectra of the aqueous amorphous pentacene derivative nanoparticle suspensions and of a dilute solution of TSBS-pentacene in toluene. The inset shows a schematic representation of parent singlet excitons in the amorphous pentacene derivative nanoparticles, which we take to be completely absent of long-range order but to have the possibility of local structural order between nearest neighbors (see example main text and ref. 97). (b) Normalized absorption spectra of the aqueous amorphous pentacene derivative nanoparticle suspensions highlighting the peak position of the origin band of the lowest-energy singlet transition.
