The photoluminescence(PL)peak of poly p-phenyl phenol(PPP)is at about 370-420nm excited by the light at 350nm.The absorption band edges and photon emitting peaks of the polymer are found the conjugated lengths depende...The photoluminescence(PL)peak of poly p-phenyl phenol(PPP)is at about 370-420nm excited by the light at 350nm.The absorption band edges and photon emitting peaks of the polymer are found the conjugated lengths dependent on molecular weight of polymer.In the transient luminescence measurement the lifetime of PL decay is determined to be 2.0ns which is supposed an evidence of polaron excitation recombination.The electroluminescence is observed with aluminum/PPP/indium-tinoxide cell.展开更多
The performances such as the operating-voltage and the brightness of three types of devices: single-layer device, double-layer device and three-layer device, were examined. It is demonstrated that the I-V characterist...The performances such as the operating-voltage and the brightness of three types of devices: single-layer device, double-layer device and three-layer device, were examined. It is demonstrated that the I-V characteristics of single-layer device depends not on the applied voltage but instead on the electric-field strength, and the brightness increased by a factor of 50 and the operating-voltage decreased when introducing one electron transporting layer or an electron transporting layer and one hole blocking layer between the light emitting layer and the negative electrode. In fact, it is imperative to match the energy level of each layer in the electroluminescent device in order to improve its comprehensive performances.展开更多
Blue-green electroluminescent diodes utilizing tris(8-Quinolino1ato)-aluminum doped poly(vinylcarbazole)have been demonstrated.A Schottky-type electroluminescent diode of the polymer film is driven at 20V and has a pe...Blue-green electroluminescent diodes utilizing tris(8-Quinolino1ato)-aluminum doped poly(vinylcarbazole)have been demonstrated.A Schottky-type electroluminescent diode of the polymer film is driven at 20V and has a peak emission wavelength of 490nm at room temperature with lifetime up to 4 h.展开更多
The polymer electroluminescence (EL) device with PBD as carriers confinement layer yields bright blue emission having intensity of 300cd/m^(2),in same case the device without PBD layer have luminance only 44 cd/m^(2)....The polymer electroluminescence (EL) device with PBD as carriers confinement layer yields bright blue emission having intensity of 300cd/m^(2),in same case the device without PBD layer have luminance only 44 cd/m^(2).The effect of PBD layer on EL characteristic was studied.The results show that only in EL devices with PBD thick-ness over 30nm,the holes are completely confined in emitting layer.The luminance over 2000cd/m^(2) can be obtained by inserting an electron injecting layer between the negative electrode and PED to increase the electron injection.展开更多
By placing a hole blocking layer between the polymer and the metallic electrode,we have achieved improved efficiencies for blue electroluminescent devices fabricated with poly(N-vinylcarbazole)doped with 1,1,4,4,-tetr...By placing a hole blocking layer between the polymer and the metallic electrode,we have achieved improved efficiencies for blue electroluminescent devices fabricated with poly(N-vinylcarbazole)doped with 1,1,4,4,-tetraphenyl-1,3-butadiene as the emitter layer and with aluminum and indium/tin-oxide as the electron and hole injecting electrodes.This bilayer device yields bright blue emission having intensity of 300cd/m^(2),in same case the devices without hole blocking layer have luminance of only 44 cd/m^(2).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
文摘The photoluminescence(PL)peak of poly p-phenyl phenol(PPP)is at about 370-420nm excited by the light at 350nm.The absorption band edges and photon emitting peaks of the polymer are found the conjugated lengths dependent on molecular weight of polymer.In the transient luminescence measurement the lifetime of PL decay is determined to be 2.0ns which is supposed an evidence of polaron excitation recombination.The electroluminescence is observed with aluminum/PPP/indium-tinoxide cell.
基金the National Natural Science Foundation of China。
文摘The performances such as the operating-voltage and the brightness of three types of devices: single-layer device, double-layer device and three-layer device, were examined. It is demonstrated that the I-V characteristics of single-layer device depends not on the applied voltage but instead on the electric-field strength, and the brightness increased by a factor of 50 and the operating-voltage decreased when introducing one electron transporting layer or an electron transporting layer and one hole blocking layer between the light emitting layer and the negative electrode. In fact, it is imperative to match the energy level of each layer in the electroluminescent device in order to improve its comprehensive performances.
文摘Blue-green electroluminescent diodes utilizing tris(8-Quinolino1ato)-aluminum doped poly(vinylcarbazole)have been demonstrated.A Schottky-type electroluminescent diode of the polymer film is driven at 20V and has a peak emission wavelength of 490nm at room temperature with lifetime up to 4 h.
基金Supported by the National Natural Science Foundation of Chinaby Key Research Projection from the National Laboratory of Integrated Optical Electronics of Jilin University
文摘The polymer electroluminescence (EL) device with PBD as carriers confinement layer yields bright blue emission having intensity of 300cd/m^(2),in same case the device without PBD layer have luminance only 44 cd/m^(2).The effect of PBD layer on EL characteristic was studied.The results show that only in EL devices with PBD thick-ness over 30nm,the holes are completely confined in emitting layer.The luminance over 2000cd/m^(2) can be obtained by inserting an electron injecting layer between the negative electrode and PED to increase the electron injection.
文摘By placing a hole blocking layer between the polymer and the metallic electrode,we have achieved improved efficiencies for blue electroluminescent devices fabricated with poly(N-vinylcarbazole)doped with 1,1,4,4,-tetraphenyl-1,3-butadiene as the emitter layer and with aluminum and indium/tin-oxide as the electron and hole injecting electrodes.This bilayer device yields bright blue emission having intensity of 300cd/m^(2),in same case the devices without hole blocking layer have luminance of only 44 cd/m^(2).
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.
