Measurements of the electric-field-induced change in fluorescence decay profile of methylene-linked carbazole and terephthalic acid methyl ester in a PMMA polymer film

The electric-field-induced change in the fluorescence decay profile has been measured for methylene-linked carbazole (CZ) and terephthalic acid methyl ester (TAME) doped in a PMMA polymer film, using a picosecond time-resolved decay measurement system combined with a bipolar sample bias. The average lifetime of the fluorescence emitted from the locally excited state of CZ becomes shorter in the presence of an external electric field (F), confirming that the rate of photoinduced electron transfer from CZ to TAME is enhanced by F. Different decaying portions of the multi-exponential decay were also found to give different efficiencies in the electric field effect from each other, depending on the methylene chain length.