A gadolinium ternary complex, tris(1 phenyl 3 methyl 4 isobutyryl 5 pyrazolone) (2, 2′ dipyridyl) gadolinium Gd(PMIP) 3(Bipy) was synthesized and used as a light emitting material in the organic electrolumin...A gadolinium ternary complex, tris(1 phenyl 3 methyl 4 isobutyryl 5 pyrazolone) (2, 2′ dipyridyl) gadolinium Gd(PMIP) 3(Bipy) was synthesized and used as a light emitting material in the organic electroluminescent devices. The devices exhibited the green electroluminescent (EL) emission peaking at 513 nm, originating from the Gd(PMIP) 3(Bipy). By improving the configuration, the device with a structure of ITO/poly(N vinylcarbazole) (PVK) (40 nm)/Gd(PMIP) 3(Bipy) (40 nm)/tris (8 hydroxyquinoline) aluminum (ALQ) (40 nm)/Mg∶Ag(200 nm)/Ag(100 nm) showed higher performance and a maximum luminance of 340 cd·m -2 at 18 V.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
Intrinsically stretchable electroluminescent(EL)devices have emerged as pivotal components with transformative potential in various domains,including wearable technology,medical devices,human-machine interfaces,and co...Intrinsically stretchable electroluminescent(EL)devices have emerged as pivotal components with transformative potential in various domains,including wearable technology,medical devices,human-machine interfaces,and communications.This mini-review focuses on the recent progress in the development of intrinsically stretchable EL materials,highlighting milestones and breakthroughs in the field.The article discusses the basic principles,advantages,and disadvantages associated with various EL mechanisms and materials.Specific material design strategies,particularly focusing on light-emitting layers,are thoroughly examined,detailing their implementation in EL devices and the resultant EL performance.We also provide perspectives on the active challenges and future research needs for each type of EL material and devices for achieving stretchable designs,together with some insights into the future trajectory of stretchable EL technology.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
Organic light-emitting diodes (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,l1'-biphenyl-4,4'-diamine (NPB) and tris (8-hydroxyquinoline) aluminium (Alq3 ) are improved by using a thin MgF2 buffe...Organic light-emitting diodes (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,l1'-biphenyl-4,4'-diamine (NPB) and tris (8-hydroxyquinoline) aluminium (Alq3 ) are improved by using a thin MgF2 buffer layer sandwiched between the indium tin oxide (ITO) anode and hole transporting layer (HTL) of NPB. The current-voltage curves of the OLEDs with MgF2 buffers shift to lower voltages, which can be explained by the tunnelling effect. Under 10 V bias, the current density and brightness for the optimized OLED with a 1.0-nm MgF2 are 196A/m^2 and 517cd/m^2, respectively, while for the OLED without anode buffer layer are only 109A/m^2 and 156cd/m^2, The atomic force microscopy shows that the rms roughness of NPB on ITO/MgF2 is only 1/3 of NPB on bare ITO. The improved morphology of the HTL would lead to more robust OLEDs. The OLED with a 1.0-nm MgF2 layer has a long lifetime of more than five times of the MgF2-free reference device due to the combined electrical and morphological effects of the MgF2 layer.展开更多
Improved performances are obtained in organic light-emitting diodes (OLEDs) based on the indium-tin oxide (ITO) anode processed with ultrasonic in Al2O3 polishing solution. By optimizing the Al2O3 granularity to ...Improved performances are obtained in organic light-emitting diodes (OLEDs) based on the indium-tin oxide (ITO) anode processed with ultrasonic in Al2O3 polishing solution. By optimizing the Al2O3 granularity to 0.6μm and the ultrasonic time to 10min, smoother ITO surfaces are acquired, which lead to the enhanced hole injection, and furthermore, to improving the performance of OLEDs. Compared with the control device without any treatment, the drive voltage of treatment device falls from 9 V to 6 V at 100cd/m^2, the luminance is over three times that of the control device, reaching 25880cd/m^2 at 15 V, and the luminous efficiency is 3.82cd/A.展开更多
We investigate the effect of thermal annealing before and after cathode deposition on the stability of polymer light-emitting diodes (PLEDs) based on green fluorescent polyfluorene derivative. The annealed PLEDs exh...We investigate the effect of thermal annealing before and after cathode deposition on the stability of polymer light-emitting diodes (PLEDs) based on green fluorescent polyfluorene derivative. The annealed PLEDs exhibit improved charge transport and red-shift emission compared to the as-fabricated device. The stability of the PLEDs is largely enhanced by post-annealing before and after Ca deposition, which is attributed to the enhanced charge transport and the intimate contact between the cathode and the emissive layer.展开更多
We report the miscibility and molecular orientation of carbazole (CA) molecules in the mixed Langmuir and Langmuir-Blodgett (LB) films of CA in polymethyl methacrylate (PMMA) and stearic acid (SA) matrices. Th...We report the miscibility and molecular orientation of carbazole (CA) molecules in the mixed Langmuir and Langmuir-Blodgett (LB) films of CA in polymethyl methacrylate (PMMA) and stearic acid (SA) matrices. The lr-A isotherm confirms the formation of stable Langmuir films of CA mixed with either PMMA or SA at airwater interface. 'Characteristics of area per molecule versus molefraction and collapse pressure versus molefraction reveal complete demixing of CA and the matrix PMMA/SA molecules in the mixed films. Absorption spectroscopy certainly confirms the fact that CA molecules have preferred orientation on the substrate of the LB films.展开更多
By extending the conduction band structure, we set up a new analytical model in ZnS. Compared the results with both the old analytical model and the full band model, it is found that they are possibly in reasonable ag...By extending the conduction band structure, we set up a new analytical model in ZnS. Compared the results with both the old analytical model and the full band model, it is found that they are possibly in reasonable agreement with the full band method and we can improve the calculation precision. Another important work is to reduce the programme computation time using the method of data fitting scattering rate curves.展开更多
文摘A gadolinium ternary complex, tris(1 phenyl 3 methyl 4 isobutyryl 5 pyrazolone) (2, 2′ dipyridyl) gadolinium Gd(PMIP) 3(Bipy) was synthesized and used as a light emitting material in the organic electroluminescent devices. The devices exhibited the green electroluminescent (EL) emission peaking at 513 nm, originating from the Gd(PMIP) 3(Bipy). By improving the configuration, the device with a structure of ITO/poly(N vinylcarbazole) (PVK) (40 nm)/Gd(PMIP) 3(Bipy) (40 nm)/tris (8 hydroxyquinoline) aluminum (ALQ) (40 nm)/Mg∶Ag(200 nm)/Ag(100 nm) showed higher performance and a maximum luminance of 340 cd·m -2 at 18 V.
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 US National Science Foundation CAREER(award no.2239618).
文摘Intrinsically stretchable electroluminescent(EL)devices have emerged as pivotal components with transformative potential in various domains,including wearable technology,medical devices,human-machine interfaces,and communications.This mini-review focuses on the recent progress in the development of intrinsically stretchable EL materials,highlighting milestones and breakthroughs in the field.The article discusses the basic principles,advantages,and disadvantages associated with various EL mechanisms and materials.Specific material design strategies,particularly focusing on light-emitting layers,are thoroughly examined,detailing their implementation in EL devices and the resultant EL performance.We also provide perspectives on the active challenges and future research needs for each type of EL material and devices for achieving stretchable designs,together with some insights into the future trajectory of stretchable EL technology.
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.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50325310, 50473009 and 50433020.
文摘Organic light-emitting diodes (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,l1'-biphenyl-4,4'-diamine (NPB) and tris (8-hydroxyquinoline) aluminium (Alq3 ) are improved by using a thin MgF2 buffer layer sandwiched between the indium tin oxide (ITO) anode and hole transporting layer (HTL) of NPB. The current-voltage curves of the OLEDs with MgF2 buffers shift to lower voltages, which can be explained by the tunnelling effect. Under 10 V bias, the current density and brightness for the optimized OLED with a 1.0-nm MgF2 are 196A/m^2 and 517cd/m^2, respectively, while for the OLED without anode buffer layer are only 109A/m^2 and 156cd/m^2, The atomic force microscopy shows that the rms roughness of NPB on ITO/MgF2 is only 1/3 of NPB on bare ITO. The improved morphology of the HTL would lead to more robust OLEDs. The OLED with a 1.0-nm MgF2 layer has a long lifetime of more than five times of the MgF2-free reference device due to the combined electrical and morphological effects of the MgF2 layer.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60207003 and 60376028, and the Special Funds for Major State Basic Research Project of China under Grant No 2003CB314703
文摘Improved performances are obtained in organic light-emitting diodes (OLEDs) based on the indium-tin oxide (ITO) anode processed with ultrasonic in Al2O3 polishing solution. By optimizing the Al2O3 granularity to 0.6μm and the ultrasonic time to 10min, smoother ITO surfaces are acquired, which lead to the enhanced hole injection, and furthermore, to improving the performance of OLEDs. Compared with the control device without any treatment, the drive voltage of treatment device falls from 9 V to 6 V at 100cd/m^2, the luminance is over three times that of the control device, reaching 25880cd/m^2 at 15 V, and the luminous efficiency is 3.82cd/A.
基金Supported by the National Natural Science Foundation of China under Grant No 50573076, the National Basic Research Program of China under Grant No 2002CB613401, the Bai-Ren-Ji-Hua Programme of Chinese Academy of Sciences, and the Fund of National Key Laboratory of Integrated 0ptoelectronics of Jilin University (No 2006-JLU-01).
文摘We investigate the effect of thermal annealing before and after cathode deposition on the stability of polymer light-emitting diodes (PLEDs) based on green fluorescent polyfluorene derivative. The annealed PLEDs exhibit improved charge transport and red-shift emission compared to the as-fabricated device. The stability of the PLEDs is largely enhanced by post-annealing before and after Ca deposition, which is attributed to the enhanced charge transport and the intimate contact between the cathode and the emissive layer.
文摘We report the miscibility and molecular orientation of carbazole (CA) molecules in the mixed Langmuir and Langmuir-Blodgett (LB) films of CA in polymethyl methacrylate (PMMA) and stearic acid (SA) matrices. The lr-A isotherm confirms the formation of stable Langmuir films of CA mixed with either PMMA or SA at airwater interface. 'Characteristics of area per molecule versus molefraction and collapse pressure versus molefraction reveal complete demixing of CA and the matrix PMMA/SA molecules in the mixed films. Absorption spectroscopy certainly confirms the fact that CA molecules have preferred orientation on the substrate of the LB films.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60576016, 10374001 and 10434030, the National Key Basic Research and Development Programme of China under Grant No 2003CB314707, the Postdoctoral Science Foundation of China under Grant No 2003034324.
文摘By extending the conduction band structure, we set up a new analytical model in ZnS. Compared the results with both the old analytical model and the full band model, it is found that they are possibly in reasonable agreement with the full band method and we can improve the calculation precision. Another important work is to reduce the programme computation time using the method of data fitting scattering rate curves.