Hajime Yamagata

TL;DR: In this article, a delicate interplay exists between intrachain order and inter-chain coupling as revealed through the emission 0−0/0−1 vibronic intensity ratios of poly-3-hexylthiophene (P3HT) assembled in toluene.

TL;DR: An admixture of charge-transfer excitations into the lowest singlet excited states form the origin of the Davydov splitting and mediate instantaneous singlet exciton fission by direct optical excitation of coherently coupled single and double exciton states, in agreement with recent experiments.

TL;DR: A new model for analyzing the photophysics of polymer aggregates is introduced taking into account exciton motion along a polymer chain and across polymer chains, and the predictions neatly account for the H-like dominance exhibited by the PL from spin-cast films and the J- like dominance exhibited from highly ordered P3HT nanofibers self-assembled in toluene.

TL;DR: A theory for polarized absorption in crystalline oligoacenes is presented, which includes Frenkel exciton coupling, the coupling between Frenkel and charge-transfer (CT) excitons, and the coupling of all neutral and ionic excited states to the dominant ring-breathing vibrational mode.

TL;DR: In the presence of disorder and for T > 0 K, λ2S(R) is closely approximated by the exciton coherence number N( coh), thereby providing a simple and direct way of extracting N(coh) from the photoluminescence spectrum.