Fig. 4: Photo-induced TA spectra of Chl-D solution and film.

a Pristine Chl-D solution and the ones (b) purged with N2 gas or (c) blended with HQ excited at 650 nm (Qy band of Chl-D solution), and the TA spectra of Chl-D film which included (d) neat Chl-D film and the ones blended with (e) β-carotene or (f) HQ excited at 737 nm (Qy band of Chl-D film). The gray broken-dotted line represents the inverted steady-state absorption spectrum of each sample for comparison.