Extended Data Fig. 5: Electronic and Vibrational dynamics of internal conversion from D2 to D1 state of TTM-TPA.
From: Decoupling excitons from high-frequency vibrations in organic molecules
a) transient absorption signal in the form of differential transmission (ΔT/T) upon photo-excitation with P1 and P2 pump pulse at different time delays (the purple shaded area: P2 excitation; and magenta line: P1 excitation). b) electronic population dynamics of the D2 exciton for a representative wavelength (790–800 nm) which turns out to be 670 ± 125 fs. (The method is described in SI section 8). c, d, the spectra obtained from the vibrational coherence at early time (150–1500 fs) and later time (650–2000 fs) in band selective excitation experiment with c) P2 excitation and d) P1 excitation at representative probe wavelength (710–750 nm). It is important to note that a very close resemblance of the later time spectra of P2 excitation and early time spectra of the P1 excitation is consistent with this barrierless and coherent internal conversion process from D2 to D1.
