Singlet exciton migration in a conjugated polymer by picosecond time-resolved photoluminescence

The transient photoluminescence (PL) of DO-PPV (poly-(2,5-dioctyloxy-1,4-ph enylene vinylene)) solution in chloroform was investigated by picosecond ti me-resolved PL spectroscopy. An ultrafast rise of PL and the following sing le exponential decay with a time constant of about 400 ps were assigned to the formation of the intrachain exciton and its decay process, respectively . The redshift of the PL emission spectrum with time was caused by the subs equent exciton migration among the different conjugated segments in the DO- PPV polymer.