Superlattices consisting of alternating layers of organic/polymeric materials have been fabricated from tris(8-hydroxyquinoline)aluminum(Alq3) and poly(N-vinylcarbazole)(PVK) by a multisource-type high-vacuum organic ...Superlattices consisting of alternating layers of organic/polymeric materials have been fabricated from tris(8-hydroxyquinoline)aluminum(Alq3) and poly(N-vinylcarbazole)(PVK) by a multisource-type high-vacuum organic molecular deposition.The characteristics of superlattice structures are determined by the small-angle X-ray diffraction,optical absorption and photoluminescence.The electroluminescent devices with the superlattice structure have also been fabricated and the emission characteristics are discussed.展开更多
Organic multiple quantum wells(OMQWs) consisting of alternating layers of organic materials have been fabricated from tris(8-hydroxyquinoline) aluminum(Alq)and 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,3-oxadiazole(P...Organic multiple quantum wells(OMQWs) consisting of alternating layers of organic materials have been fabricated from tris(8-hydroxyquinoline) aluminum(Alq)and 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,3-oxadiazole(PBD) by a multisource-type high-vacuum organic molecular deposition.From the small-angle X-ray diffraction patterns of Alq/PBD OMQWs,a periodically layered structure is confirmed through the entire stack.The Alq layer thickness in the OMQWs was varied from 1 nm to 4 nm.From the optical absorption,photoluminescence and electroluminescence measurements,it is found that the exciton energy shifts to higher energy with decreasing Alq layer thickness,The changes of the exciton energy could be interpreted as the confinement effects of exciton in the Alq thin layers.Narrowing of the emission spectrum has also been observed for the electroluminescent devices (ELDs) with the OMQWs structure at room temperature.展开更多
By using air-stable alumminum as cathode,molecular doped polymer (MDP)blue light emitting diodes(LEDs)were constructed.Poly(N-vinylcarbazole(PVK)doped with,1,1,4,4-tetrapheny 1-1,3-butadiens(TPB)was used as the light-...By using air-stable alumminum as cathode,molecular doped polymer (MDP)blue light emitting diodes(LEDs)were constructed.Poly(N-vinylcarbazole(PVK)doped with,1,1,4,4-tetrapheny 1-1,3-butadiens(TPB)was used as the light-emitting layer,a layer of 2-(4-biphenylyl)-5-(4-terbutypheny)1-3,4-oxadiazole(PBD) as hole-blocking,electron-transporting layer and a layer of tris(8-quinolinolate)-Aluminum(Alq3)film also worked as an electron-transporting layer.The device with structure of ITO/PVK;TPB/PBD/Alq3/Al was fabricated.Blue emis-sion began at about 4V,more than 1000 cd/m^2 was achieved at 14V.This is the lowest turn-on voltage for polymeric lgiht-emitting diodes(PLEDS)used air-stable elec-trodes.Such low-operating voltage,especially using air-stable aluminum as cathode,may be helpful for the devices to be used in commercially viable displays.展开更多
文摘Superlattices consisting of alternating layers of organic/polymeric materials have been fabricated from tris(8-hydroxyquinoline)aluminum(Alq3) and poly(N-vinylcarbazole)(PVK) by a multisource-type high-vacuum organic molecular deposition.The characteristics of superlattice structures are determined by the small-angle X-ray diffraction,optical absorption and photoluminescence.The electroluminescent devices with the superlattice structure have also been fabricated and the emission characteristics are discussed.
文摘Organic multiple quantum wells(OMQWs) consisting of alternating layers of organic materials have been fabricated from tris(8-hydroxyquinoline) aluminum(Alq)and 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,3-oxadiazole(PBD) by a multisource-type high-vacuum organic molecular deposition.From the small-angle X-ray diffraction patterns of Alq/PBD OMQWs,a periodically layered structure is confirmed through the entire stack.The Alq layer thickness in the OMQWs was varied from 1 nm to 4 nm.From the optical absorption,photoluminescence and electroluminescence measurements,it is found that the exciton energy shifts to higher energy with decreasing Alq layer thickness,The changes of the exciton energy could be interpreted as the confinement effects of exciton in the Alq thin layers.Narrowing of the emission spectrum has also been observed for the electroluminescent devices (ELDs) with the OMQWs structure at room temperature.
文摘By using air-stable alumminum as cathode,molecular doped polymer (MDP)blue light emitting diodes(LEDs)were constructed.Poly(N-vinylcarbazole(PVK)doped with,1,1,4,4-tetrapheny 1-1,3-butadiens(TPB)was used as the light-emitting layer,a layer of 2-(4-biphenylyl)-5-(4-terbutypheny)1-3,4-oxadiazole(PBD) as hole-blocking,electron-transporting layer and a layer of tris(8-quinolinolate)-Aluminum(Alq3)film also worked as an electron-transporting layer.The device with structure of ITO/PVK;TPB/PBD/Alq3/Al was fabricated.Blue emis-sion began at about 4V,more than 1000 cd/m^2 was achieved at 14V.This is the lowest turn-on voltage for polymeric lgiht-emitting diodes(PLEDS)used air-stable elec-trodes.Such low-operating voltage,especially using air-stable aluminum as cathode,may be helpful for the devices to be used in commercially viable displays.
