The mixture of Nano-graphite and organic vehicles doped to Nano-diamond paste. The suitable paste proportion was found. Nano-diamond film (NDF) was prepared by sol-gel coating method on ITO glass at 3000/min. The fiel...The mixture of Nano-graphite and organic vehicles doped to Nano-diamond paste. The suitable paste proportion was found. Nano-diamond film (NDF) was prepared by sol-gel coating method on ITO glass at 3000/min. The field emission characteristics of luminance-current, luminance-voltage and luminance-power of Nano-diamond film were analyzed and tested. Comparing these tested curves, the luminance was well proportional to current was got. Theoretic, the inner resistance of NDF field emission display (FED) consumes electric energy and real voltage change between the cathode and the anode of NDF-FED was very small after electrons emit. So the characteristic of NDF-FED was preferable to describe by luminance-current linear relationship, which was advantageous to device tested and designed.展开更多
This work presents novel field emission organic light emitting diodes(FEOLEDs) with dynode,in which an organic EL light-emitting layer is used instead of an inorganic phosphor thin film in the field emission display(F...This work presents novel field emission organic light emitting diodes(FEOLEDs) with dynode,in which an organic EL light-emitting layer is used instead of an inorganic phosphor thin film in the field emission display(FED).The proposed FEOLEDs introduce field emission electrons into organic light emitting diodes(OLEDs),which exhibit a higher luminous efficiency than conventional OLED.The field emission electrons emitted from the carbon nanotubes(CNTs) cathode and to be amplified by impact the dynode in vacuum.These field emission electrons are injected into the multi-layer organic materials of OLED to increase the electron density.Additionally,the proposed FEOLED increase the luminance of OLED from 10 820 cd/m2 to 24 782 cd/m2 by raising the current density of OLED from an external electron source.The role of FEOLED is to add the quantity of electrons-holes pairs in OLED,which increase the exciton and further increase the luminous efficiency of OLED.Under the same operating current density,the FEOLED exhibits a higher luminous efficiency than that of OLED.展开更多
Aiming at the influences of poor contact at carbon nanotube (CNT)/electrode interface on luminescence stability in printed CNT film, a new co-sintering process for cathode fabrication was presented to improve the lumi...Aiming at the influences of poor contact at carbon nanotube (CNT)/electrode interface on luminescence stability in printed CNT film, a new co-sintering process for cathode fabrication was presented to improve the luminescent stability of fully printed CNT-FED. By co-sintering the printed silver and CNT layers, CNTs geometrically matched with Ag surface and/or embedded into Ag layer at the bottom of the co-sintered film, large CNTs block and bulk silver nested each other at the top of the co-sintered film. All these structures increased the contact area at CNT/Ag interface, which could increase the probability of forming ohmic contact at CNT/Ag interface. The luminescent stability of printed CNT-FED with co-sintered cathode could be improved as 5.6 times high as that of common devices.展开更多
We have developed a computerized system for measuring field electron emission （FE） and field ionization （FI）, which has a three-electrode configuration with emitters biased up to 25 kV, and is programmed by the La...We have developed a computerized system for measuring field electron emission （FE） and field ionization （FI）, which has a three-electrode configuration with emitters biased up to 25 kV, and is programmed by the Labview software. The current-voltage curves of nano-tip tungsten and carbon nanotube （CNT） arrays were measured. The electron emission of CNTs proceeded with a turn-on field of 1.24 V/μm and a threshold field of 1.85 V/μm. Compared to the field emission, field ionization turned on at 3.5 V/μm. Raman spectroscopy and scanning electron microscopy （SEM） measurements showed degradation of the CNTs after FE/FI testing. The measurement of a W-tip revealed strong electron emission and instability behavior at a field strength higher than 7.0 V/μm.展开更多
A carbon-nanotube-based normally-on-driving under-gate field emission display(FED)panel and its operation principle are presented.In this panel,field emission electrons are extracted directly from the cathode by the h...A carbon-nanotube-based normally-on-driving under-gate field emission display(FED)panel and its operation principle are presented.In this panel,field emission electrons are extracted directly from the cathode by the high anode voltage.The image is realized by modulating the voltage of under-gate,whose value is less than the cathode voltage,to stop the cathode producing field emission electrons.The electric field inside the emission region is calculated by the finite element method.The emission property of the cathode is also studied by numerical calculation method.The results indicate that a uniform and large emission area can be obtained in this new under-gate FED panel.This study provides powerful theoretic support for the feasibility of this new kind of under-gate FED panel.展开更多
The field emission digital display tube with a nano-crystalline graphite cold cathode is designed and fabricated. Under the control of the driving circuits, a dynamic digital display with uniform luminance distributio...The field emission digital display tube with a nano-crystalline graphite cold cathode is designed and fabricated. Under the control of the driving circuits, a dynamic digital display with uniform luminance distribution is realized. The luminance of the character segments is 190 cd/m2 at the operating voltage of 900 V. And the stable emission is attained with a fluctuation of about 3% at an average segment current of 75 μA. The results demonstrate that nano-crystalline graphite film is a promising material for cold cathode.展开更多
Based on our study on field emission from multi-walled carbon nanotubes （MWNTs）, we experimentally manufactured field emission display （FED） triode with a MWNTs cold cathode, and demonstrated an excellent performa...Based on our study on field emission from multi-walled carbon nanotubes （MWNTs）, we experimentally manufactured field emission display （FED） triode with a MWNTs cold cathode, and demonstrated an excellent performance of MWNTs as field emitters. The measured luminance of the phosphor screens was 1.8 × 10^3 cd/m^2 for green light. The emission is stable with a fluctuation of only 1.5% at an average current of 260 μA.展开更多
Under reduction atmosphere, a blue sky rare earth silicate light storage and emission material was prepared by high temperature solid phase synthesis. The best constituent ratio of this material was determined through...Under reduction atmosphere, a blue sky rare earth silicate light storage and emission material was prepared by high temperature solid phase synthesis. The best constituent ratio of this material was determined through orthogonal experiment, and its excitation and emission spectra and X-ray diffraction patterns were measured. And a comparative study was conducted on its application properties.展开更多
Ultra-narrow-band phosphors have gained widespread applications in lighting and displays to enhance brightness and improve color saturation.Typical phosphor designs employ UCr_(4)C_(4)-type compounds and designing new...Ultra-narrow-band phosphors have gained widespread applications in lighting and displays to enhance brightness and improve color saturation.Typical phosphor designs employ UCr_(4)C_(4)-type compounds and designing new narrow-band phosphors with high color purity is a major challenge.Here,we explored a Eu^(2+)-doped Ba_(5)GeO_(4)Br_(6)phosphor,showing a narrow-band blue emission(λ_(em)=436 nm) excitation at the near-ultraviolet light with a full width at half maximum of 30.7 nm and high color purity of 96.6%.In addition,attractive cathodoluminescence characteristics were systematically analyzed by varying filament current(30-70 mA) and accelerating voltage(3-7 eV).Robust anti-degradation behavior and color point stability under continuous electron beam bombardment were confirmed.Given its excellent performance in photoluminescence and cathodoluminescence,application in wide color gamut displays appears promising.Using commercial phosphors β-SiAlON:Eu^(2+)and K_(2)SiF6:Mn^(4+)as green and red light co nverte rs respectively,and the title phosphor as the blue light converters,the fabricated w-LED exhibits a wide color gamut of 82% NTSC.展开更多
Two-dimensional （2D） materials, e.g., graphene, transition metal dichalcogenides （TMDs）, and black phosphorus （BP）, have demonstrated fascinating electrical and optical characteristics and exhibited great potent...Two-dimensional （2D） materials, e.g., graphene, transition metal dichalcogenides （TMDs）, and black phosphorus （BP）, have demonstrated fascinating electrical and optical characteristics and exhibited great potential in optoelectronic applications. High-performance and multifunctional devices were achieved by employing diverse designs, such as hybrid systems with nanostructured materials, bulk semiconductors and organics, forming 2D heterostructures. In this review, we mainly discuss the recent progress of 2D materials in high-responsive photodetectors, light-emitting devices and single photon emitters. Hybrid systems and van der Waals heterostructure-based devices are emphasized, which exhibit great potential in state-of-the-art applications.展开更多
MXene(M_(n+1)Xn)is an emerging class of layered two-dimensional(2D)materials,which are derived from their bulk-state MAX phase(M_(n+1)AXn,where M:early transition metal,A:group element 13 and 14,and X:carbon and/or ni...MXene(M_(n+1)Xn)is an emerging class of layered two-dimensional(2D)materials,which are derived from their bulk-state MAX phase(M_(n+1)AXn,where M:early transition metal,A:group element 13 and 14,and X:carbon and/or nitrogen).MXenes have found wide-ranging applications in energy storage devices,sensors,catalysis,etc.owing to their high electronic conductivity and wide range of optical absorption.However,the absence of semiconducting MXenes has limited their applications related to light emission.Research has shown that quantum dots(QDs)derived from MXene(MQDs)not only retain the properties of the parent MXene but also demonstrate significant improvement on light emission and quantum yield(QY).The optical properties and photoluminescence(PL)emission mechanisms of these light-emitting MQDs have not been comprehensively investigated.Recently,work on light-emitting MQDs has shown good progress,and MQDs exhibiting multi-color PL emission along with high QY have been fabricated.The synthesis methods also play a vital role in determining the light emission properties of these MQDs.This review provides an overview of light-emitting MQDs and their synthesis methods,optical properties,and applications in various optical,sensory,and imaging devices.The future prospects of light-emitting MQDs are also discussed to provide an insight that helps to further advance the progress on MQDs.展开更多
Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 an...Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 and CaF2 crystals were performed by irradiating the samples with 405 and 375 nm diode lasers. Chromaticity diagrams are developed from spectral measurements. Dy3+-doped CaF2 revealed bright white light emission having peaks at 492, 570 and 654 nm. The measured color coordinates are x = 0.322 and y = 0.340 for Dy3+-doped CaF2 and these values are close to those of sunlight and the coordinated color temperature is 6147 K, under 405 m laser excitation. Eu3+-doped LaF3 revealed twenty emission peaks in the visible wavelength region. The color coordinates measured for LaF3: Eu3+ are x = 0.283 and y = 0.293 under 405 nm diode laser excitation and the color temperature is 9557 K. Eu3+-doped LaF3 provides cool white-light, under 405 nm diode laser excitation. Tb3+-doped fluoride crystals revealed bright white light under low power diode laser excitation. The measured color coordinates for Tb3+-doped CaF2 are x = 0.329 and y = 0.558 and the color temperature is 7713 K. The color coordinates for LaF3: Tb3+ are x = 0.342 and y = 0.365 and the coordinated color temperature is 5370 K. These values are close to those of sunlight.展开更多
Light emitting diode(LED) is the fourth generation lighting source,but it has some shortcomings such as complex chip packaging process and the unbalanced light color of phosphor in long-time application.In this study,...Light emitting diode(LED) is the fourth generation lighting source,but it has some shortcomings such as complex chip packaging process and the unbalanced light color of phosphor in long-time application.In this study,a kind of Eu-terephthalic acid/Tb-sulfosalicylate/ZrO_(2)/ZnZrO_(3)(Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3))phosphor with warm white light emission properties was prepared,and the warm white light LED(wWLEDs) was successfully prepared by encapsulating Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3) phosphors together with 270 nm UV-chip.The ZrO_(2)/ZnZrO_(3),Tb-SSA/ZrO_(2)/ZnZrO_(3) and Eu-PTA/ZrO_(2)/ZnZrO_(3) samples show blue emission,green emission and red emission under deep ultraviolet(UV,270 nm) excitation,respectively.The Tb-SSA and Eu-PTA are co-doped into ZrO_(2)/ZnZrO_(3) matrix with blue emission to achieve the warm white light emission,and the light color can be adjusted by controlling the doping amount of Eu^(3+)-and Tb^(3+).Through the excitation method of single-component phosphor by the single chip,the complex chip packaging process of w-LED can be solved.By doping rare earth organic complexes into porous ZrO_(2)/ZnZrO_(3) matrix,the problems of the light color unbalanced of phosphor and the low luminescence intensity of rare earth doped metal oxides composites can be solved.展开更多
文摘The mixture of Nano-graphite and organic vehicles doped to Nano-diamond paste. The suitable paste proportion was found. Nano-diamond film (NDF) was prepared by sol-gel coating method on ITO glass at 3000/min. The field emission characteristics of luminance-current, luminance-voltage and luminance-power of Nano-diamond film were analyzed and tested. Comparing these tested curves, the luminance was well proportional to current was got. Theoretic, the inner resistance of NDF field emission display (FED) consumes electric energy and real voltage change between the cathode and the anode of NDF-FED was very small after electrons emit. So the characteristic of NDF-FED was preferable to describe by luminance-current linear relationship, which was advantageous to device tested and designed.
基金the I-Shou University,Taiwan,for financially supporting this research under Contract No.ISU99-01-06Taiwan Science Council under Contract No.NSC98-2218-E-214-001 and 98-2221-E-214-003-MY3
文摘This work presents novel field emission organic light emitting diodes(FEOLEDs) with dynode,in which an organic EL light-emitting layer is used instead of an inorganic phosphor thin film in the field emission display(FED).The proposed FEOLEDs introduce field emission electrons into organic light emitting diodes(OLEDs),which exhibit a higher luminous efficiency than conventional OLED.The field emission electrons emitted from the carbon nanotubes(CNTs) cathode and to be amplified by impact the dynode in vacuum.These field emission electrons are injected into the multi-layer organic materials of OLED to increase the electron density.Additionally,the proposed FEOLED increase the luminance of OLED from 10 820 cd/m2 to 24 782 cd/m2 by raising the current density of OLED from an external electron source.The role of FEOLED is to add the quantity of electrons-holes pairs in OLED,which increase the exciton and further increase the luminous efficiency of OLED.Under the same operating current density,the FEOLED exhibits a higher luminous efficiency than that of OLED.
基金supported by the National Natural Science Foundation of China(Grant No.60036010)the National High Technology Research and Development Program of China(Grant No.2001AA313090)the Doctoral Foundation of the National Education Administration of P.R.China(Grant No.20020698014).
文摘Aiming at the influences of poor contact at carbon nanotube (CNT)/electrode interface on luminescence stability in printed CNT film, a new co-sintering process for cathode fabrication was presented to improve the luminescent stability of fully printed CNT-FED. By co-sintering the printed silver and CNT layers, CNTs geometrically matched with Ag surface and/or embedded into Ag layer at the bottom of the co-sintered film, large CNTs block and bulk silver nested each other at the top of the co-sintered film. All these structures increased the contact area at CNT/Ag interface, which could increase the probability of forming ohmic contact at CNT/Ag interface. The luminescent stability of printed CNT-FED with co-sintered cathode could be improved as 5.6 times high as that of common devices.
基金supported by National Natural Science Foundation(No.11075121)the International Science and Technology Cooperation Program(No.2010DFA02010)Three Gorges University of China(KJ2009B011)
文摘We have developed a computerized system for measuring field electron emission （FE） and field ionization （FI）, which has a three-electrode configuration with emitters biased up to 25 kV, and is programmed by the Labview software. The current-voltage curves of nano-tip tungsten and carbon nanotube （CNT） arrays were measured. The electron emission of CNTs proceeded with a turn-on field of 1.24 V/μm and a threshold field of 1.85 V/μm. Compared to the field emission, field ionization turned on at 3.5 V/μm. Raman spectroscopy and scanning electron microscopy （SEM） measurements showed degradation of the CNTs after FE/FI testing. The measurement of a W-tip revealed strong electron emission and instability behavior at a field strength higher than 7.0 V/μm.
基金supported by the National Key Basic Research Program 973 (No.2003CB314706).
文摘A carbon-nanotube-based normally-on-driving under-gate field emission display(FED)panel and its operation principle are presented.In this panel,field emission electrons are extracted directly from the cathode by the high anode voltage.The image is realized by modulating the voltage of under-gate,whose value is less than the cathode voltage,to stop the cathode producing field emission electrons.The electric field inside the emission region is calculated by the finite element method.The emission property of the cathode is also studied by numerical calculation method.The results indicate that a uniform and large emission area can be obtained in this new under-gate FED panel.This study provides powerful theoretic support for the feasibility of this new kind of under-gate FED panel.
基金Science and Technology Foundation of-the Ministry of Education of China(No.205091)Natural Science Foundation of Education Department of Henan Province of China(No.2007510018).
文摘The field emission digital display tube with a nano-crystalline graphite cold cathode is designed and fabricated. Under the control of the driving circuits, a dynamic digital display with uniform luminance distribution is realized. The luminance of the character segments is 190 cd/m2 at the operating voltage of 900 V. And the stable emission is attained with a fluctuation of about 3% at an average segment current of 75 μA. The results demonstrate that nano-crystalline graphite film is a promising material for cold cathode.
基金This work was supported by the Science and Technology Foundation of Education Ministry of China under Grant No. 205091.
文摘Based on our study on field emission from multi-walled carbon nanotubes （MWNTs）, we experimentally manufactured field emission display （FED） triode with a MWNTs cold cathode, and demonstrated an excellent performance of MWNTs as field emitters. The measured luminance of the phosphor screens was 1.8 × 10^3 cd/m^2 for green light. The emission is stable with a fluctuation of only 1.5% at an average current of 260 μA.
文摘Under reduction atmosphere, a blue sky rare earth silicate light storage and emission material was prepared by high temperature solid phase synthesis. The best constituent ratio of this material was determined through orthogonal experiment, and its excitation and emission spectra and X-ray diffraction patterns were measured. And a comparative study was conducted on its application properties.
基金Project supported by the Natural Science Foundation of Shaanxi Provincial Department of Education,China (21JK0708)the Key Laboratory for Special Function Materials and Structure Design of the Ministry of the Education of Lanzhou University,China (lzujbky-2021-kb06)。
文摘Ultra-narrow-band phosphors have gained widespread applications in lighting and displays to enhance brightness and improve color saturation.Typical phosphor designs employ UCr_(4)C_(4)-type compounds and designing new narrow-band phosphors with high color purity is a major challenge.Here,we explored a Eu^(2+)-doped Ba_(5)GeO_(4)Br_(6)phosphor,showing a narrow-band blue emission(λ_(em)=436 nm) excitation at the near-ultraviolet light with a full width at half maximum of 30.7 nm and high color purity of 96.6%.In addition,attractive cathodoluminescence characteristics were systematically analyzed by varying filament current(30-70 mA) and accelerating voltage(3-7 eV).Robust anti-degradation behavior and color point stability under continuous electron beam bombardment were confirmed.Given its excellent performance in photoluminescence and cathodoluminescence,application in wide color gamut displays appears promising.Using commercial phosphors β-SiAlON:Eu^(2+)and K_(2)SiF6:Mn^(4+)as green and red light co nverte rs respectively,and the title phosphor as the blue light converters,the fabricated w-LED exhibits a wide color gamut of 82% NTSC.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61422503 and 61376104)the Open Research Funds of Key Laboratory of MEMS of Ministry of Education of Chinathe Fundamental Research Funds for the Central Universities of China
文摘Two-dimensional （2D） materials, e.g., graphene, transition metal dichalcogenides （TMDs）, and black phosphorus （BP）, have demonstrated fascinating electrical and optical characteristics and exhibited great potential in optoelectronic applications. High-performance and multifunctional devices were achieved by employing diverse designs, such as hybrid systems with nanostructured materials, bulk semiconductors and organics, forming 2D heterostructures. In this review, we mainly discuss the recent progress of 2D materials in high-responsive photodetectors, light-emitting devices and single photon emitters. Hybrid systems and van der Waals heterostructure-based devices are emphasized, which exhibit great potential in state-of-the-art applications.
基金supported by National Research Foundation of Korea(2019R1A2C1006586).
文摘MXene(M_(n+1)Xn)is an emerging class of layered two-dimensional(2D)materials,which are derived from their bulk-state MAX phase(M_(n+1)AXn,where M:early transition metal,A:group element 13 and 14,and X:carbon and/or nitrogen).MXenes have found wide-ranging applications in energy storage devices,sensors,catalysis,etc.owing to their high electronic conductivity and wide range of optical absorption.However,the absence of semiconducting MXenes has limited their applications related to light emission.Research has shown that quantum dots(QDs)derived from MXene(MQDs)not only retain the properties of the parent MXene but also demonstrate significant improvement on light emission and quantum yield(QY).The optical properties and photoluminescence(PL)emission mechanisms of these light-emitting MQDs have not been comprehensively investigated.Recently,work on light-emitting MQDs has shown good progress,and MQDs exhibiting multi-color PL emission along with high QY have been fabricated.The synthesis methods also play a vital role in determining the light emission properties of these MQDs.This review provides an overview of light-emitting MQDs and their synthesis methods,optical properties,and applications in various optical,sensory,and imaging devices.The future prospects of light-emitting MQDs are also discussed to provide an insight that helps to further advance the progress on MQDs.
文摘Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 and CaF2 crystals were performed by irradiating the samples with 405 and 375 nm diode lasers. Chromaticity diagrams are developed from spectral measurements. Dy3+-doped CaF2 revealed bright white light emission having peaks at 492, 570 and 654 nm. The measured color coordinates are x = 0.322 and y = 0.340 for Dy3+-doped CaF2 and these values are close to those of sunlight and the coordinated color temperature is 6147 K, under 405 m laser excitation. Eu3+-doped LaF3 revealed twenty emission peaks in the visible wavelength region. The color coordinates measured for LaF3: Eu3+ are x = 0.283 and y = 0.293 under 405 nm diode laser excitation and the color temperature is 9557 K. Eu3+-doped LaF3 provides cool white-light, under 405 nm diode laser excitation. Tb3+-doped fluoride crystals revealed bright white light under low power diode laser excitation. The measured color coordinates for Tb3+-doped CaF2 are x = 0.329 and y = 0.558 and the color temperature is 7713 K. The color coordinates for LaF3: Tb3+ are x = 0.342 and y = 0.365 and the coordinated color temperature is 5370 K. These values are close to those of sunlight.
基金supported by the National Natural Science Foundation of China (51572034)the Jilin Province Science and Technology Development Plan Project of China (20220203168SF)。
文摘Light emitting diode(LED) is the fourth generation lighting source,but it has some shortcomings such as complex chip packaging process and the unbalanced light color of phosphor in long-time application.In this study,a kind of Eu-terephthalic acid/Tb-sulfosalicylate/ZrO_(2)/ZnZrO_(3)(Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3))phosphor with warm white light emission properties was prepared,and the warm white light LED(wWLEDs) was successfully prepared by encapsulating Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3) phosphors together with 270 nm UV-chip.The ZrO_(2)/ZnZrO_(3),Tb-SSA/ZrO_(2)/ZnZrO_(3) and Eu-PTA/ZrO_(2)/ZnZrO_(3) samples show blue emission,green emission and red emission under deep ultraviolet(UV,270 nm) excitation,respectively.The Tb-SSA and Eu-PTA are co-doped into ZrO_(2)/ZnZrO_(3) matrix with blue emission to achieve the warm white light emission,and the light color can be adjusted by controlling the doping amount of Eu^(3+)-and Tb^(3+).Through the excitation method of single-component phosphor by the single chip,the complex chip packaging process of w-LED can be solved.By doping rare earth organic complexes into porous ZrO_(2)/ZnZrO_(3) matrix,the problems of the light color unbalanced of phosphor and the low luminescence intensity of rare earth doped metal oxides composites can be solved.
