TRANSIENT PHOTOINDUCED ABSORPTION OF ONE-DIMENSIONAL EXCITONS AND BIEXCITONS DURING LATTICE RELATION

Transient photoinduced absorption spectra of one-dimensional excitons and biexcitons coupled with lattice vibrations are calculated with a two-band model by molecular dynamics. It is shown that the absorption peaks corresponding to the transition from photoexcited B-u excitons to A(g) excitons and the lowest biexciton shift as self-trapping proceeds, where the former shifts to higher energy and the latter to lower energy. This difference is understood by means of the relaxation energy of B-u, A(g) excitons and the biexciton. The transient absorbance change near the B-u --> A(g) peak is also discussed.