| 초록 |
We report the effect of side chain length at C-9 of polyfluorenes and blends with polyvinylcarbazole(PVK) on photoluminescence with respect to fluorescence life time and energy transfer. The side chains we choose are alkyl groups (butyl, hexyl, octyl). Energy transfer from PVK excimer to Polyfluorene derivatives exhibits improved PL intensity and suppressed excimer emission in case of PVK/PDBF(9/1), PVK/PDHF(9/1, which have butyl, hexyl group attached at C-9 of polyfluorene. In case of longer side chain, octyl, at C-9 of polyfluorene, however, PL intensity in blends is less than in homopolymer. Time Correlated Single Photon Counting method is used to see the change of fluorescence life time as a side chain length of polyfluorene. The more increases the side chain length of polyfluorenes, the more increases their fluorescence life time, and the same tendency is observed at the blends. Optimum side chain length on photoluminescence of polyfluorene in blends is C4-C6. |
