Luminescent conjugated polymers have been extensively studied due to their use as active materials in cheap and efficient light-emitting diodes(LED).However

despite the fact that many exciting progresses have been achieved

a lot of work is still needed to develop new polymers(or modified version of existing ones) that can emit red

green and blue light.Doping of the emission layers in LEDs with luminescent dyes can control the colour of emission as well as improve device efficiency.Porphyrins have potential applications in LED because of their pure red-light emission and optimized efficiency over all other fluorescent materials.However

there have been few reports about them used in LEDs.This is due to their propensity to π-π stack

which causes the material non-luminescent in the solid state.These problems can be overcome by incorporating porphyrin chromophores as the side-chain groups to control the porphyrin-porphyrin interactions in solid states.In this paper

the transient fluorescence dynamics of two porphyrin side-chain polyers

P[(por)A-S] and P[(por)FeA-S]

were measured by using femtosecond time-resolved luminescence spectroscopy.Using nanosecond spectroscopic technology

we also measured the transient fluorescence dynamics of the monomer porphyrin molecules(TPP).The results show that all the transient luminescence decays are composed of two components:an initial fast decay(58 ps for P[(por)FeA-S]

and 200 ps for P[(por)A-S])

and a following slowing relaxation processes(217 ps for P[(por)FeA-S]

and 2.1 ns for P[(por)A-S]).The interchain and intrachain nonradiative exciton relaxation processes may play an important role in the luminescence dynamics in the porphyrin side-chain polymer films.The intermolecular interactions result in the faster fluorescence decay than that of TPP.The intramolecular charge transfer and the intermolecular interactions result in the ultrafast fluorescence decay in P[(por)FeA-S] compared with that of P[(por)A-S].