Novel blue light-emitting poly（aryl ether）s comprising of bipolar oligofluorene pendants as chromophores have been designed and synthesized, in which pyrimidine and arylamine moieties are utilized as the electron ac...Novel blue light-emitting poly（aryl ether）s comprising of bipolar oligofluorene pendants as chromophores have been designed and synthesized, in which pyrimidine and arylamine moieties are utilized as the electron acceptor and electron donor, respectively. Through varying n bridge length from monofluorene to bifluorene and end-cappers from hydrogen to carbazole and diphenylamine, the emission color of the resulting polymers covers from deep blue to greenish blue, and their HOMO and LUMO levels can be modulated to facilitate charge injection to improve the device performance. Polymer light- emitting diodes （PLEDs） are fabricated with the device structure of ITO/poly（3,4-ethylenedioxythiophene）：poly（styrene sulfonic acid） （PEDOT：PSS） （50 nm）/polymer （80 nm）/Ca （10 nm）/Al （200 nm）. Among these polymers, P2Cz5F-Py with bifluorene bridge and carbazole end-capper shows excellent trade-off between the efficiency and emission wavelength, having a peak luminous efficiency as high as 1.26 cd/A and Commission Internationale de L＇Eclairage （CIE） coordinates of （0.17,0.17）.展开更多
A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths （OF,） to the different positions of the spherical [60]fullerene （C60） through...A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths （OF,） to the different positions of the spherical [60]fullerene （C60） through a rigid linkage. The conjugates were characterized by IH-NMR, 13C-NMR, FTIR, EA and MALDI-TOF mass spectrometry. The optical and electronic properties of the conjugates were studied by UV-Vis absorption spectroscopy, fluorescence spectrometry, and cyclic voltammetry. The results from UV-Vis absorption spectroscopy and cyclic voltammetry indicated that the energy profiles of C60 and OFn remained unchanged when different lengths of OFn were attached to C60. The electron affinities of the OFn-C60 conjugates were close to that of C60, while slight electronic interaction was found between the two individual chromophores （C60 and OFn） in their ground states. The fluorescence spectra exhibited a complete fluorescence quenching in the toluene solution, suggesting an effective energy transfer from OFn to C60. It presents a systematic study on the self- assembly, structure-property relationship, and potential technical applications of the conjugates.展开更多
We present theoretical investigations on structure-property correlations in fluorenone （FLO） and benzothiadiazole （BT） substituted oligofluorenes （OFLs） derived mainly from the chain morphology, thermal vibratio...We present theoretical investigations on structure-property correlations in fluorenone （FLO） and benzothiadiazole （BT） substituted oligofluorenes （OFLs） derived mainly from the chain morphology, thermal vibration and conjugated extent. Both the vertical absorptions and the vibrationally-resolved absorption and fluorescence spectra have been calculated by the com- bination of ab initio and time-dependent density functional theory. By properly taking into account of the anharmonic torsion potentials in the OFLs, we have reasonably reproduced the experimentally observed spectroscopic features. Both FLO and BT on-chain chemical defects acting as charge-trapping sites for singlet excitations, are responsible for long wave absorption and emission species, and thus alter the blue light-emitting properties of OFLs. As temperature decreases, the electronic spectral lineshapes of FLO-substituted oligomers become more structured. The lineshapes of BT-substituted oligomers are always smooth and featureless because of less low collective modes resonance. A more gentle excited poten-tial energy surface of BT-mixed molecules can enhance electronic delocalization and achieve bigger red shifts.展开更多
基金financially supported by the 973 Project(Nos.2009CB623601 and 2009CB930603)National Natural Science Foundation of China(No.21074130)Science Fund for Creative Research Groups(No.20921061)
文摘Novel blue light-emitting poly（aryl ether）s comprising of bipolar oligofluorene pendants as chromophores have been designed and synthesized, in which pyrimidine and arylamine moieties are utilized as the electron acceptor and electron donor, respectively. Through varying n bridge length from monofluorene to bifluorene and end-cappers from hydrogen to carbazole and diphenylamine, the emission color of the resulting polymers covers from deep blue to greenish blue, and their HOMO and LUMO levels can be modulated to facilitate charge injection to improve the device performance. Polymer light- emitting diodes （PLEDs） are fabricated with the device structure of ITO/poly（3,4-ethylenedioxythiophene）：poly（styrene sulfonic acid） （PEDOT：PSS） （50 nm）/polymer （80 nm）/Ca （10 nm）/Al （200 nm）. Among these polymers, P2Cz5F-Py with bifluorene bridge and carbazole end-capper shows excellent trade-off between the efficiency and emission wavelength, having a peak luminous efficiency as high as 1.26 cd/A and Commission Internationale de L＇Eclairage （CIE） coordinates of （0.17,0.17）.
基金financially supported by the International Science&Technology Cooperation Program of China(No.2010DFB70470)the Natural Science Foundation of Shanghai(No.10ZR1407600)
文摘A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths （OF,） to the different positions of the spherical [60]fullerene （C60） through a rigid linkage. The conjugates were characterized by IH-NMR, 13C-NMR, FTIR, EA and MALDI-TOF mass spectrometry. The optical and electronic properties of the conjugates were studied by UV-Vis absorption spectroscopy, fluorescence spectrometry, and cyclic voltammetry. The results from UV-Vis absorption spectroscopy and cyclic voltammetry indicated that the energy profiles of C60 and OFn remained unchanged when different lengths of OFn were attached to C60. The electron affinities of the OFn-C60 conjugates were close to that of C60, while slight electronic interaction was found between the two individual chromophores （C60 and OFn） in their ground states. The fluorescence spectra exhibited a complete fluorescence quenching in the toluene solution, suggesting an effective energy transfer from OFn to C60. It presents a systematic study on the self- assembly, structure-property relationship, and potential technical applications of the conjugates.
文摘We present theoretical investigations on structure-property correlations in fluorenone （FLO） and benzothiadiazole （BT） substituted oligofluorenes （OFLs） derived mainly from the chain morphology, thermal vibration and conjugated extent. Both the vertical absorptions and the vibrationally-resolved absorption and fluorescence spectra have been calculated by the com- bination of ab initio and time-dependent density functional theory. By properly taking into account of the anharmonic torsion potentials in the OFLs, we have reasonably reproduced the experimentally observed spectroscopic features. Both FLO and BT on-chain chemical defects acting as charge-trapping sites for singlet excitations, are responsible for long wave absorption and emission species, and thus alter the blue light-emitting properties of OFLs. As temperature decreases, the electronic spectral lineshapes of FLO-substituted oligomers become more structured. The lineshapes of BT-substituted oligomers are always smooth and featureless because of less low collective modes resonance. A more gentle excited poten-tial energy surface of BT-mixed molecules can enhance electronic delocalization and achieve bigger red shifts.
