Photoluminescence properties and exciton decay dynamics in a porphyrin side-chain polymer, poly[porphyrin acrylate- acrylonitrile （abbreviated p[（por）A-AN]）, have been investigated by femtosecond time-resolved pho...Photoluminescence properties and exciton decay dynamics in a porphyrin side-chain polymer, poly[porphyrin acrylate- acrylonitrile （abbreviated p[（por）A-AN]）, have been investigated by femtosecond time-resolved photoluminescence spectroscopy. All the luminescences of p[（por）A-AN] films are due to the emissive decay of the photoexcited singlet excitons in the porphyrins. The luminescence efficiencies and lifetimes are increased for samples from pure films to dilute blend films. However, they are increased as the intrachain concentration of the porphyrin sidechain groups is decreased. The intrachain rotation motions of porphyrin sidechain groups result in the initial ultrafast luminescence decays, which are much faster than those due to the interchain interactions. All the samples show no significant red-shift and broadening of the transient luminescence spectra. The interchain and intrachain nonradiative exciton relaxation processes may play an important role in the luminescence dynamics in the p[（por）A-AN] films. The possible origin of different intrachain and interchain dynamic behaviours in p[（por）A-AN] films is discussed.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60478013, 20571089 and 10274107）, the Natural Science Foundation of Guangdong Province, China （Grant No 05101819）, and the Doctoral Program Foundation of Institute of Higher Education of China（Grant No 20040558031）.
文摘Photoluminescence properties and exciton decay dynamics in a porphyrin side-chain polymer, poly[porphyrin acrylate- acrylonitrile （abbreviated p[（por）A-AN]）, have been investigated by femtosecond time-resolved photoluminescence spectroscopy. All the luminescences of p[（por）A-AN] films are due to the emissive decay of the photoexcited singlet excitons in the porphyrins. The luminescence efficiencies and lifetimes are increased for samples from pure films to dilute blend films. However, they are increased as the intrachain concentration of the porphyrin sidechain groups is decreased. The intrachain rotation motions of porphyrin sidechain groups result in the initial ultrafast luminescence decays, which are much faster than those due to the interchain interactions. All the samples show no significant red-shift and broadening of the transient luminescence spectra. The interchain and intrachain nonradiative exciton relaxation processes may play an important role in the luminescence dynamics in the p[（por）A-AN] films. The possible origin of different intrachain and interchain dynamic behaviours in p[（por）A-AN] films is discussed.
