Three kinds of pyrazolines were designed and synthesized. Their structures were elucidated by IR, (HNMR)-H-1, MS, UV and elemental analysis. Their luminescent properties were determined, which indicated that they had ...Three kinds of pyrazolines were designed and synthesized. Their structures were elucidated by IR, (HNMR)-H-1, MS, UV and elemental analysis. Their luminescent properties were determined, which indicated that they had strong blue fluorescent properties. One of them was designed to have good film formation. All the three kinds of pyrazolines can be used as blue organic electroluminescence materials (OELMs).展开更多
The in.jection of charge carriers from the electron/hole injection or transport layers in polymer light-emitting diodes potentially increases the device efficiency not by changing of charge intensity but by lattice di...The in.jection of charge carriers from the electron/hole injection or transport layers in polymer light-emitting diodes potentially increases the device efficiency not by changing of charge intensity but by lattice distortion variation and quasi-particle interactions. From the low-dimensional condensed matter physics perspective, a valid mechanism is proposed to bring a type of novel channels that, under a proper external electric field, transition- forbidden triplet excitons are transformed and partially charged by charge carriers （polarons/bipolarons）, thus are able to emit light and to enhance fluorescence greatly.展开更多
The effect of dipole layer of Alq3 and metal on organic electroluminescence in organic light-emitting diodes(OLEDs) was discussed. The relations among energy level alignment,interface charge transfer and dipole layer ...The effect of dipole layer of Alq3 and metal on organic electroluminescence in organic light-emitting diodes(OLEDs) was discussed. The relations among energy level alignment,interface charge transfer and dipole layer formation were well analyzed. An interface dipole layer and charge transfer were observed by XPS and UPS. As for Alq3 with metallic film such as Al and Mg,N 1s,O 1s and C 1s all move to low binding energy. Both Alq3/Al and Alq3/Mg have different electron spectrum from that of simple Alq3 film. It is really the reason of the interface energy change that the metal atoms located near the interface move to organic layer and then chemically interact with O and C of Alq3. The injection voltage barrier heights of electrons at Alq3/Al and Alq3/Mg interface are 0.1 eV and 0.2 eV,respectively. Charge transfer lowers electrons injection voltage barrier height and forms good electrons injection interfaces. The width of dipole layer is about 5 nm. The knowledge of such interface dipole layer is essential for a proper understanding of the physical processes at the metal/organic interface.展开更多
The major features of the display technologies for 3G cellular phone are reviewed. The comparison between their potential candidates for 3G cellular phone is given, and a detailed discussion is made on passive matrix ...The major features of the display technologies for 3G cellular phone are reviewed. The comparison between their potential candidates for 3G cellular phone is given, and a detailed discussion is made on passive matrix organic electroluminescent display technology. A novel method to improve display contrast ratio is presented. Finally several 3G phone set prototypes with OLED display panels are given as well as the market forecast.展开更多
Long life green emitting matrix display based on organic light emitting diode is reported. The pixel number is 96×60, equivalent pixel size 0.4×0.4 mm 2, and the pixel gap 0.1 mm. An image with no crossta...Long life green emitting matrix display based on organic light emitting diode is reported. The pixel number is 96×60, equivalent pixel size 0.4×0.4 mm 2, and the pixel gap 0.1 mm. An image with no crosstalk between pixels is obtained. The average luminance of these pixels at duty cycle of 1/64 is 100 cd/m 2, and the power consumption is 0.6 W. The dark room contrast of 1∶100 is achieved without using a polarization filter.展开更多
A kind of pyrazoline derivative 1, 3 -bis(phenyl)- 5 - (2 -phenanthrene)-2-pyrazo line(TPP) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material....A kind of pyrazoline derivative 1, 3 -bis(phenyl)- 5 - (2 -phenanthrene)-2-pyrazo line(TPP) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material. Two devices with structures as indium-tin-oxide(ITO) /TPP (50 nm)/tris-(8-hydroxyquinoline) aluminum(Alq3) (50 nm)/A1 (1 5 0 nm) and ITO /TPP (5 0 nm)/lithium tera- (8 -hydroxy-uinolinato)boron(LiBq4(5 0nm)/Alq3 (5 nm)/Al (l 5 0 nm) were fabricated, they showed good e electroluminescent(EL)performance and TPP was proved to be a good hole transporting material.展开更多
A bilayer Al 2O 3/Al is used as a cathode for organic electroluminescent devices. Six times higher electroluminescent efficiency is obtained without increasing the threshold voltage. The improvement is believed to b...A bilayer Al 2O 3/Al is used as a cathode for organic electroluminescent devices. Six times higher electroluminescent efficiency is obtained without increasing the threshold voltage. The improvement is believed to be due to increasing injecting electron density, which improves the balanced injection of carriers, and declines the exciton-quenching and carrier-trapping centers that are intrinsic to the interface between of emitting layer and cathode.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
Organic electroluminescent thin film using Znq 2 (Znq 2) as the emitting layer material with structure of glass/ITO/Znq 2/Al (cell)was fabricated. The V I curve, V B curve and electroluminescent spectra of the cell we...Organic electroluminescent thin film using Znq 2 (Znq 2) as the emitting layer material with structure of glass/ITO/Znq 2/Al (cell)was fabricated. The V I curve, V B curve and electroluminescent spectra of the cell were measured. Meanwhile the fluorescent spectra, excited spectra and absorption spectra of Znq 2 with powder and film states were also measured.展开更多
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
Double-layer organic electroluminescent devices have been constructed. A new fluorescent dye, 9,10-bis(phenylethynyl)anthracence, was chosen as the dopant which was molecularly dispersed in the polymer film, and green...Double-layer organic electroluminescent devices have been constructed. A new fluorescent dye, 9,10-bis(phenylethynyl)anthracence, was chosen as the dopant which was molecularly dispersed in the polymer film, and green light was observed from the device with luminance of 130cd/m(2) at 17V.展开更多
Remarkable improvement in efficiency and stability has been observed in a doped organic electroluminescence device, which consists of a hole-transport layer, an electron-transport layer and a luminescent layer. The ho...Remarkable improvement in efficiency and stability has been observed in a doped organic electroluminescence device, which consists of a hole-transport layer, an electron-transport layer and a luminescent layer. The hole-transport layer is a N,N’-bis(3-methyphenyl)-N,N’-diphenylbenzidine film. The doped emitting layer consists of 8-(quinolinolate)-aluminum as the host and rubrene as the emission dopant. The doped device demonstrated a brightness in excess of 40 000 cd/m 2 and the maximum external quantum efficiency of 3.4%, which is about six times and four times respectively greater than those of the undoped device. For no packaged deviced, a luminance half-life on the order of about 230 h has been achieved under a constant current density of 15 mA/cm 2, starting at 500 cd/m 2 at the room temperature.展开更多
The discovery of 2D organic semiconductors of atomically thin structures has attracted great attention due to their emerging optical, electronic, optoelectronic and mechatronic properties. Recent progress in such orga...The discovery of 2D organic semiconductors of atomically thin structures has attracted great attention due to their emerging optical, electronic, optoelectronic and mechatronic properties. Recent progress in such organic nanostructures has opened new opportunities for engineering material properties in many ways, such as, 0D/1D/2D nanoparticles hybridization, strain engineering, atomic doping etc. Moreover, 2D organic nanostructures exhibit a unique feature of bio–functionality and are highly sensitive to bio-analytes. Such peculiar behavior in 2D organics can be utilized to design highly-efficient bio-sensors. Also, a bio-molecular integrated electronic/optoelectronic device with enhanced performance can be attained. Furthermore, the bio-degradable, biocompatible, biometabolizable, non-toxic behaviour and natural origin of organic nanomaterials can address the current ecological concerns of increasing inorganic material based electronic waste. This review highlights the benefits of 2D organic semiconductors. Considering the importance of strategic techniques for growing thin 2D organic layers,this review summarizes progress towards this direction. The possible challenges for long-time stability and future research directions in 2D organic nano electronics/optoelectronics are also discussed. We believe that this review article provides immense research interests in organic 2D nanotechnology for exploiting green technologies in the future.展开更多
White organic light-emitting diodes with a blue emitting material fluorene-centred ethylene-liked carbazole oligomer （Cz6F） doped into polyvinyl carbazole （PVK） as the single light-emitting layer are reported. The...White organic light-emitting diodes with a blue emitting material fluorene-centred ethylene-liked carbazole oligomer （Cz6F） doped into polyvinyl carbazole （PVK） as the single light-emitting layer are reported. The optical properties of Cz6F, PVK, and PVK：Cz6F blends are studied. Single and double layer devices are fabri- cated by using PVK： Cz6F blends, and the device with the configuration of indium tin oxide （ITO）/PVK：Cz6F/ tris（8-hydroxyquinolinate）aluminium （Alq3）/LiF/A1 exhibits white light emission with Commission Internationale de l＇Eclairage chromaticity coordinates of （0.30, 0.33） and a brightness of 402 cd/m^2. The investigation reveals that the white light is composed of a blue-green emission originating from the excimer of Cz6F molecules and a red emission from an electroplex from the PVK：Cz6F blend films.展开更多
文摘Three kinds of pyrazolines were designed and synthesized. Their structures were elucidated by IR, (HNMR)-H-1, MS, UV and elemental analysis. Their luminescent properties were determined, which indicated that they had strong blue fluorescent properties. One of them was designed to have good film formation. All the three kinds of pyrazolines can be used as blue organic electroluminescence materials (OELMs).
文摘The in.jection of charge carriers from the electron/hole injection or transport layers in polymer light-emitting diodes potentially increases the device efficiency not by changing of charge intensity but by lattice distortion variation and quasi-particle interactions. From the low-dimensional condensed matter physics perspective, a valid mechanism is proposed to bring a type of novel channels that, under a proper external electric field, transition- forbidden triplet excitons are transformed and partially charged by charge carriers （polarons/bipolarons）, thus are able to emit light and to enhance fluorescence greatly.
基金Project(06JJ20034) supported by the Natural Science Foundation of Hunan Province, ChinaProject supported by the Theory Science Development Foundation of Central South University, China
文摘The effect of dipole layer of Alq3 and metal on organic electroluminescence in organic light-emitting diodes(OLEDs) was discussed. The relations among energy level alignment,interface charge transfer and dipole layer formation were well analyzed. An interface dipole layer and charge transfer were observed by XPS and UPS. As for Alq3 with metallic film such as Al and Mg,N 1s,O 1s and C 1s all move to low binding energy. Both Alq3/Al and Alq3/Mg have different electron spectrum from that of simple Alq3 film. It is really the reason of the interface energy change that the metal atoms located near the interface move to organic layer and then chemically interact with O and C of Alq3. The injection voltage barrier heights of electrons at Alq3/Al and Alq3/Mg interface are 0.1 eV and 0.2 eV,respectively. Charge transfer lowers electrons injection voltage barrier height and forms good electrons injection interfaces. The width of dipole layer is about 5 nm. The knowledge of such interface dipole layer is essential for a proper understanding of the physical processes at the metal/organic interface.
文摘The major features of the display technologies for 3G cellular phone are reviewed. The comparison between their potential candidates for 3G cellular phone is given, and a detailed discussion is made on passive matrix organic electroluminescent display technology. A novel method to improve display contrast ratio is presented. Finally several 3G phone set prototypes with OLED display panels are given as well as the market forecast.
文摘Long life green emitting matrix display based on organic light emitting diode is reported. The pixel number is 96×60, equivalent pixel size 0.4×0.4 mm 2, and the pixel gap 0.1 mm. An image with no crosstalk between pixels is obtained. The average luminance of these pixels at duty cycle of 1/64 is 100 cd/m 2, and the power consumption is 0.6 W. The dark room contrast of 1∶100 is achieved without using a polarization filter.
文摘A kind of pyrazoline derivative 1, 3 -bis(phenyl)- 5 - (2 -phenanthrene)-2-pyrazo line(TPP) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material. Two devices with structures as indium-tin-oxide(ITO) /TPP (50 nm)/tris-(8-hydroxyquinoline) aluminum(Alq3) (50 nm)/A1 (1 5 0 nm) and ITO /TPP (5 0 nm)/lithium tera- (8 -hydroxy-uinolinato)boron(LiBq4(5 0nm)/Alq3 (5 nm)/Al (l 5 0 nm) were fabricated, they showed good e electroluminescent(EL)performance and TPP was proved to be a good hole transporting material.
文摘A bilayer Al 2O 3/Al is used as a cathode for organic electroluminescent devices. Six times higher electroluminescent efficiency is obtained without increasing the threshold voltage. The improvement is believed to be due to increasing injecting electron density, which improves the balanced injection of carriers, and declines the exciton-quenching and carrier-trapping centers that are intrinsic to the interface between of emitting layer and cathode.
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Organic electroluminescent thin film using Znq 2 (Znq 2) as the emitting layer material with structure of glass/ITO/Znq 2/Al (cell)was fabricated. The V I curve, V B curve and electroluminescent spectra of the cell were measured. Meanwhile the fluorescent spectra, excited spectra and absorption spectra of Znq 2 with powder and film states were also measured.
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Double-layer organic electroluminescent devices have been constructed. A new fluorescent dye, 9,10-bis(phenylethynyl)anthracence, was chosen as the dopant which was molecularly dispersed in the polymer film, and green light was observed from the device with luminance of 130cd/m(2) at 17V.
基金The National Natural Science Foundation of China , National "863" P
文摘Remarkable improvement in efficiency and stability has been observed in a doped organic electroluminescence device, which consists of a hole-transport layer, an electron-transport layer and a luminescent layer. The hole-transport layer is a N,N’-bis(3-methyphenyl)-N,N’-diphenylbenzidine film. The doped emitting layer consists of 8-(quinolinolate)-aluminum as the host and rubrene as the emission dopant. The doped device demonstrated a brightness in excess of 40 000 cd/m 2 and the maximum external quantum efficiency of 3.4%, which is about six times and four times respectively greater than those of the undoped device. For no packaged deviced, a luminance half-life on the order of about 230 h has been achieved under a constant current density of 15 mA/cm 2, starting at 500 cd/m 2 at the room temperature.
基金financial support from National Science Foundation China (No. 61775147)Australian Research Council (ARC) No. DP180103238
文摘The discovery of 2D organic semiconductors of atomically thin structures has attracted great attention due to their emerging optical, electronic, optoelectronic and mechatronic properties. Recent progress in such organic nanostructures has opened new opportunities for engineering material properties in many ways, such as, 0D/1D/2D nanoparticles hybridization, strain engineering, atomic doping etc. Moreover, 2D organic nanostructures exhibit a unique feature of bio–functionality and are highly sensitive to bio-analytes. Such peculiar behavior in 2D organics can be utilized to design highly-efficient bio-sensors. Also, a bio-molecular integrated electronic/optoelectronic device with enhanced performance can be attained. Furthermore, the bio-degradable, biocompatible, biometabolizable, non-toxic behaviour and natural origin of organic nanomaterials can address the current ecological concerns of increasing inorganic material based electronic waste. This review highlights the benefits of 2D organic semiconductors. Considering the importance of strategic techniques for growing thin 2D organic layers,this review summarizes progress towards this direction. The possible challenges for long-time stability and future research directions in 2D organic nano electronics/optoelectronics are also discussed. We believe that this review article provides immense research interests in organic 2D nanotechnology for exploiting green technologies in the future.
基金Project supported by the National Basic Research Program of China (Grant No. 2009CB623605)the National Natural Science Foundation of China (Grant No. 50673035)Program for New Century Excellent Talents in Universities of Ministry of Education,the 111 Project (Grant No. B06009)
文摘White organic light-emitting diodes with a blue emitting material fluorene-centred ethylene-liked carbazole oligomer （Cz6F） doped into polyvinyl carbazole （PVK） as the single light-emitting layer are reported. The optical properties of Cz6F, PVK, and PVK：Cz6F blends are studied. Single and double layer devices are fabri- cated by using PVK： Cz6F blends, and the device with the configuration of indium tin oxide （ITO）/PVK：Cz6F/ tris（8-hydroxyquinolinate）aluminium （Alq3）/LiF/A1 exhibits white light emission with Commission Internationale de l＇Eclairage chromaticity coordinates of （0.30, 0.33） and a brightness of 402 cd/m^2. The investigation reveals that the white light is composed of a blue-green emission originating from the excimer of Cz6F molecules and a red emission from an electroplex from the PVK：Cz6F blend films.
