The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measuremen...The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measurements of the thin films showed that the polymer is disorder. Electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.展开更多
The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and ...The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and the PVK emissive layer.It is believed that the PEO layer plays a key role in enhancing the device performance.In comparison to the device with Ca/Al as the cathode,the performance of the PLED with PEO/Ca/Al cathode,including the driving voltage,luminance efficiency is significantly improved.These improvements are attributed to the introduction of a thin layer of PEO that can lower the interfacial barrier and facilitate electron injection.展开更多
The electroluminescence (EL) produced by a highly luminescent phosphorescent dye Cu-4(CdropCPh)(4)L-2 (L = 1.8-bis(di-phenylphosphino)-3,6-dioxaoctane, Cu-4) doped polymer as emitting layer is reported. The effects of...The electroluminescence (EL) produced by a highly luminescent phosphorescent dye Cu-4(CdropCPh)(4)L-2 (L = 1.8-bis(di-phenylphosphino)-3,6-dioxaoctane, Cu-4) doped polymer as emitting layer is reported. The effects of the charge injection balance on the polymers, in particular, poly(N-vinylcarbazole) (PVK) have been studied by using photoluminescence and electroluminescence spectroscopy. Changes in the emission spectra demonstrate the influence of the charge injection balance on the formation ratio of triplet and singlet excitons. This provides a new technical approach to realize the color patterning in polymer LEDs.展开更多
A novel blue luminescent polymer bearing coumarin pendants was prepared. Its luminescent properties were determined indicating that it had strong blue fluorescent properties and good film formation ability. This nov...A novel blue luminescent polymer bearing coumarin pendants was prepared. Its luminescent properties were determined indicating that it had strong blue fluorescent properties and good film formation ability. This novel polymer can be used as a blue organic electroluminescent material (OELM) in organic electroluminescent devices.展开更多
Luminescent radicals have received great attention recently due to their idiographic luminescent properties and potential 100%utilization efficiency of doublets under electrical excitation.However,luminescent radical ...Luminescent radicals have received great attention recently due to their idiographic luminescent properties and potential 100%utilization efficiency of doublets under electrical excitation.However,luminescent radical polymers are rarely explored owing to their challenging molecular design and synthesis.Herein,we report an efficient approach to construct luminescent radical polymers by a super acid-catalyzed polymerization reaction proceeded at room temperature,which intrinsically avoid the heavy metal catalyst.The obtained polymers exhibit the unique paramagnetic signals,good thermal properties,and excellent photostability.Moreover,the quantifiable electroluminescence of such radical polymers was demonstrated for the first time.展开更多
A new silole monomer with two 4-(N,N-dimethylamino)phenyl substitutions on silicon atom as designed and synthesized.Three copolymers PF-N-HPS1,PF-N-HPS10 and PF-N-HPS20 were then obtained by copolymerizations of 2,7-f...A new silole monomer with two 4-(N,N-dimethylamino)phenyl substitutions on silicon atom as designed and synthesized.Three copolymers PF-N-HPS1,PF-N-HPS10 and PF-N-HPS20 were then obtained by copolymerizations of 2,7-fluorene derivatives with the silole monomer at feed ratios of 1%,10%,and 20%.Their UV-vis absorption,electrochemical,photoluminescent,and electroluminescent (EL) properties were investigated.PF-N-HPS possessed HOMO levels of 5.25-5.58 eV,and showed green emissions.Using PF-N-HPS as the emissive layer,three different polymer light-emitting diodes were fabricated as device A with ITO/PEDOT/PF-N-HPS/Al,device B with ITO/PEDOT/PF-N-HPS/Ba/Al,and device C with ITO/PEDOT/PF-N-HPS/TPBI/Ba/Al.For the device A,PF-N-HPS only showed very low EL efficiency of 0.06-0.33 cd/A,indicating that the Al cathode could not inject electron efficiently to the emissive polymers containing the 4-(N,N-dimethylamino)phenyl groups.For the device B,low work function Ba supplied better electron injections,and the EL efficiency could be improved to 0.85-1.44 cd/A.TPBI with a deep HOMO level of 6.2 eV could enhance electron transport and hole blocking.Thus modified recombinations and largely elevated EL efficiency of 4.56-7.96 cd/A were achieved for the device C.The separation of the emissive layer and metal cathode with the TPBI layer may also suppress exciton quenching at the cathode interface.展开更多
Tetraphenylethene (TPE) is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials. In this work, two thermally stable polymers (P1 and P2...Tetraphenylethene (TPE) is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials. In this work, two thermally stable polymers (P1 and P2) consisting of TPE conjugated to the 2,7-positions of fluorene and carbazole, respectively, are synthesized and characterized. Both polymers are weakly fluorescent in solutions but show greatly enhanced emission as the aggregate formation, presenting an aggregation-enhanced emission feature. Two kinds of polymer light-emitting diodes are fabricated utilizing P1 and P2 as emitters (EML) (device I: ITO/PEDOT:PSS (45 nm)/PVK:EML (1:1 wt%, 55 nm)/TPBI (38 nm)/Ca:Ag; device II: ITO/PEDOT:PSS (45 nm)/ PVK:OXD-7:EML (3:1:3 wt%, 55 nm)/TPBI (38 nm)/Ca:Ag). The device II of P2 shows the best performances, affording a maximum luminance of 6500 cd/m 2 and a high peak efficiency of 2.11 cd/A.展开更多
Since Burroughes et al. and Braun et al. reported the electroluminescence (EL) from poly(p-phenylene vinylene) (PPV) device, polymer materials have been used as the emitting layer of EL device with 4% quantum efficien...Since Burroughes et al. and Braun et al. reported the electroluminescence (EL) from poly(p-phenylene vinylene) (PPV) device, polymer materials have been used as the emitting layer of EL device with 4% quantum efficiency, and a few studies on conjugated polymer diodes emitting blue light have been reported. Because of having wider band gaps, the organic polymer is easier to realize the blue emission than inorganic semiconductors.展开更多
Tetraphenylethene(TPE)is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials.In this work,two thermally stable polymers(P1 and P2)cons...Tetraphenylethene(TPE)is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials.In this work,two thermally stable polymers(P1 and P2)consisting of TPE conjugated to the 2,7-positions of fluorene and carbazole,respectively,are synthesized and characterized.Both polymers are weakly fluorescent in solutions but show greatly enhanced emission as the aggregate formation,presenting an aggregation-enhanced emission feature.Two kinds of polymer light-emitting diodes are fabricated utilizing P1 and P2 as emitters(EML)(device I:ITO/PEDOT:PSS(45 nm)/PVK:EML(1:1 wt%,55nm)/TPBI(38 nm)/Ca:Ag;device II:ITO/PEDOT:PSS(45 nm)/PVK:OXD-7:EML(3:1:3 wt%,55 nm)/TPBI(38nm)/Ca:Ag).The device II of P2 shows the best performances,affording a maximum luminance of 6500 cd/m2and a high peak efficiency of 2.11 cd/A.展开更多
Electruluminescence (EL) in conjugated polymers based on phenyleneethynylene and thiophene (PPE) with C—C triple bonds in their main chains were studied. It was found that the emitting wavelength will red shift by in...Electruluminescence (EL) in conjugated polymers based on phenyleneethynylene and thiophene (PPE) with C—C triple bonds in their main chains were studied. It was found that the emitting wavelength will red shift by introduction of thiophene which is an electron rich moiety, the results suggest that electron rich moieties should increase effective conjugation length. Our results also show that the incorporation of thiophene units into PPE may significantly reduce the rigid rod conformation and improve the processibility.展开更多
基金Supported by the National Natural Science Foundation of China(No.2 99740 2 5 ) and Zhejiang Provincial Nature Science Foundation(No.5 9910 0 ) State Key L aboratory of Silicon MaterialsL aboratory of Organnic Solids,Institute of Chemistry,Chinese Acade
文摘The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measurements of the thin films showed that the polymer is disorder. Electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.
基金the Office of R&D,National Cheng Kung University,Taiwan
文摘The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and the PVK emissive layer.It is believed that the PEO layer plays a key role in enhancing the device performance.In comparison to the device with Ca/Al as the cathode,the performance of the PLED with PEO/Ca/Al cathode,including the driving voltage,luminance efficiency is significantly improved.These improvements are attributed to the introduction of a thin layer of PEO that can lower the interfacial barrier and facilitate electron injection.
基金This work was supported by the National Nature Foundation of China (No. 597905006).
文摘The electroluminescence (EL) produced by a highly luminescent phosphorescent dye Cu-4(CdropCPh)(4)L-2 (L = 1.8-bis(di-phenylphosphino)-3,6-dioxaoctane, Cu-4) doped polymer as emitting layer is reported. The effects of the charge injection balance on the polymers, in particular, poly(N-vinylcarbazole) (PVK) have been studied by using photoluminescence and electroluminescence spectroscopy. Changes in the emission spectra demonstrate the influence of the charge injection balance on the formation ratio of triplet and singlet excitons. This provides a new technical approach to realize the color patterning in polymer LEDs.
基金Project 29972032 was supported by the National Natural Science Foundation of China.
文摘A novel blue luminescent polymer bearing coumarin pendants was prepared. Its luminescent properties were determined indicating that it had strong blue fluorescent properties and good film formation ability. This novel polymer can be used as a blue organic electroluminescent material (OELM) in organic electroluminescent devices.
基金the National Key Research and Development Program(2016YFB0401002)the National Natural Science Foundation of China(51873159,61575146,21721005+4 种基金91833304)the Shenzhen Science and Technology Program(KQTD20170330110107046)the Key Technological Innovation Program of Hubei Province(2018AAA013)the Fundamental Research Funds for the Central Universities of China(2042019kf0234)the Funding Support from Large-scale Instrument and Equipment Sharing Foundation of Wuhan University。
文摘Luminescent radicals have received great attention recently due to their idiographic luminescent properties and potential 100%utilization efficiency of doublets under electrical excitation.However,luminescent radical polymers are rarely explored owing to their challenging molecular design and synthesis.Herein,we report an efficient approach to construct luminescent radical polymers by a super acid-catalyzed polymerization reaction proceeded at room temperature,which intrinsically avoid the heavy metal catalyst.The obtained polymers exhibit the unique paramagnetic signals,good thermal properties,and excellent photostability.Moreover,the quantifiable electroluminescence of such radical polymers was demonstrated for the first time.
基金supported by the National Natural Science Foundation of China (21225418,51003080)the National Basic Research Program of China (2013CB834705)+2 种基金the Youth Science Plan for Light of the Morning Sun of Wuhan City (201271031385)State Key Laboratory of Luminescent Materials and Devices (2012-09)Natural Science Foundation of Hubei Province (2012FFB04705)
文摘A new silole monomer with two 4-(N,N-dimethylamino)phenyl substitutions on silicon atom as designed and synthesized.Three copolymers PF-N-HPS1,PF-N-HPS10 and PF-N-HPS20 were then obtained by copolymerizations of 2,7-fluorene derivatives with the silole monomer at feed ratios of 1%,10%,and 20%.Their UV-vis absorption,electrochemical,photoluminescent,and electroluminescent (EL) properties were investigated.PF-N-HPS possessed HOMO levels of 5.25-5.58 eV,and showed green emissions.Using PF-N-HPS as the emissive layer,three different polymer light-emitting diodes were fabricated as device A with ITO/PEDOT/PF-N-HPS/Al,device B with ITO/PEDOT/PF-N-HPS/Ba/Al,and device C with ITO/PEDOT/PF-N-HPS/TPBI/Ba/Al.For the device A,PF-N-HPS only showed very low EL efficiency of 0.06-0.33 cd/A,indicating that the Al cathode could not inject electron efficiently to the emissive polymers containing the 4-(N,N-dimethylamino)phenyl groups.For the device B,low work function Ba supplied better electron injections,and the EL efficiency could be improved to 0.85-1.44 cd/A.TPBI with a deep HOMO level of 6.2 eV could enhance electron transport and hole blocking.Thus modified recombinations and largely elevated EL efficiency of 4.56-7.96 cd/A were achieved for the device C.The separation of the emissive layer and metal cathode with the TPBI layer may also suppress exciton quenching at the cathode interface.
基金the National Natural Science Foundation of China (51273053, 21104012, 21284034 and 61106017)the Natural Science Foundation of Zhejiang Province (Y4110331)+1 种基金the Program for Changjiang Scholars and Innovative Research Teams in Chinese Universities (IRT 1231)the Project of Zhejiang Key Scientific and Technological Innovation Team (2010R50017)
文摘Tetraphenylethene (TPE) is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials. In this work, two thermally stable polymers (P1 and P2) consisting of TPE conjugated to the 2,7-positions of fluorene and carbazole, respectively, are synthesized and characterized. Both polymers are weakly fluorescent in solutions but show greatly enhanced emission as the aggregate formation, presenting an aggregation-enhanced emission feature. Two kinds of polymer light-emitting diodes are fabricated utilizing P1 and P2 as emitters (EML) (device I: ITO/PEDOT:PSS (45 nm)/PVK:EML (1:1 wt%, 55 nm)/TPBI (38 nm)/Ca:Ag; device II: ITO/PEDOT:PSS (45 nm)/ PVK:OXD-7:EML (3:1:3 wt%, 55 nm)/TPBI (38 nm)/Ca:Ag). The device II of P2 shows the best performances, affording a maximum luminance of 6500 cd/m 2 and a high peak efficiency of 2.11 cd/A.
基金the National Natural Science Foundation of China and the "863" Porject.
文摘Since Burroughes et al. and Braun et al. reported the electroluminescence (EL) from poly(p-phenylene vinylene) (PPV) device, polymer materials have been used as the emitting layer of EL device with 4% quantum efficiency, and a few studies on conjugated polymer diodes emitting blue light have been reported. Because of having wider band gaps, the organic polymer is easier to realize the blue emission than inorganic semiconductors.
文摘Tetraphenylethene(TPE)is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials.In this work,two thermally stable polymers(P1 and P2)consisting of TPE conjugated to the 2,7-positions of fluorene and carbazole,respectively,are synthesized and characterized.Both polymers are weakly fluorescent in solutions but show greatly enhanced emission as the aggregate formation,presenting an aggregation-enhanced emission feature.Two kinds of polymer light-emitting diodes are fabricated utilizing P1 and P2 as emitters(EML)(device I:ITO/PEDOT:PSS(45 nm)/PVK:EML(1:1 wt%,55nm)/TPBI(38 nm)/Ca:Ag;device II:ITO/PEDOT:PSS(45 nm)/PVK:OXD-7:EML(3:1:3 wt%,55 nm)/TPBI(38nm)/Ca:Ag).The device II of P2 shows the best performances,affording a maximum luminance of 6500 cd/m2and a high peak efficiency of 2.11 cd/A.
文摘Electruluminescence (EL) in conjugated polymers based on phenyleneethynylene and thiophene (PPE) with C—C triple bonds in their main chains were studied. It was found that the emitting wavelength will red shift by introduction of thiophene which is an electron rich moiety, the results suggest that electron rich moieties should increase effective conjugation length. Our results also show that the incorporation of thiophene units into PPE may significantly reduce the rigid rod conformation and improve the processibility.
