Exciton dynamics in poly(p-pyridyl vinylene).

Abstract : We present results of picosecond photoinduced absorption (PA) and time resolved photoluminescence studies on solid and solution forms of poly(p-pyridyl vinylene). The nearly identical PA response of all forms of the polymer reflects the generation of the same primary photoexcitation, a Coulombically bound intrachain singlet exciton, and the absence of exotic species such as interchain excimers. The time dependence of the PA points to direct intersystem crossing as the origin of triplet excitons, ruling out generation of free carriers as a precursor to exciton formation.