Time-resolved spectroscopy of infrared active vibrations in 2,5-dioctyloxy poly(phenylene vinylene) films

Infrared signatures of positive and negative charge carriers in conjugated polymers with low band gaps

“…Differences in the spectral features for p-and ndoping of conjugated polymers may also be used for the identification of charge carriers formed either as primary excitations [33] or in a secondary process shortly after photoexcitation (e.g., via dissociation of excitons) [34,35] using fast time resolved spectroscopy.…”

Unraveling Excited State Dynamics of a Single-Stranded DNA-Assembled Conjugated Polyelectrolyte

“…IRAVs occur through structural distortion stemming from localized charge carriers on the π-conjugated chain creating large changes in bonding dipole moments. − When overlap of IRAV modes and polaron electronic absorption exists, Fano antiresonances (FA) emerge. ,,− The FA bands can be interrogated by time-resolved IR (TRIR), enabling monitoring of the photogenerated charged species and simultaneously accessing crucial information on structural evolution that occurs during the rapid relaxation processes, , often inaccessible by conventional spectroscopy. In particular, this was clearly demonstrated through picosecond time-resolved photoinduced IRAV studies of Mizrahi et al , and Miranda et al, by selectively detecting photogenerated polarons using IRAV modes of PPV polymer chains as a direct measure, avoiding interference with overlapping bands from neutral excitations, such as excitons and excimers as is the case with transient absorption measurements in the visible/near/IR. Similar studies on polythiophene films, enabled monitoring of polaron diffusion, charge carrier separation, and recombination, as well as detection of structural modifications attributed to polaron relaxation processes of the polymer. , …”