Time-correlated single photon counting (TCSPC) was employed to investigate the lifetime of the excited state in these materials. TBAP-α and amorphous TBAP suspended in water showed almost identical TCSPC spectra, when excited at 405 nm with average lifetimes of 2.12 and 2.13 ns, respectively. When using an aqueous suspension in ascorbic acid (0.1 M) significantly reduced fluorescence lifetimes were observed for both crystalline and amorphous TBAP (SI, Figure ). Even though TCSPC can only be used to study emissive states, these results suggest that exciton generation is similar for the amorphous and crystalline TBAP and that ascorbic acid is an effective hole scavenger for both materials.