期刊文献+
共找到507篇文章
< 1 2 26 >
每页显示 20 50 100
Growth,leaf anatomy,and photosynthesis of cotton(Gossypium hirsutum L.)seedlings in response to four light-emitting diodes and high pressure sodium lamp 被引量:1
1
作者 ZHANG Yichi LIAO Baopeng +3 位作者 LI Fangjun ENEJI AEgrinya DU Mingwei TIAN Xiaoli 《Journal of Cotton Research》 CAS 2024年第1期79-89,共11页
Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamp... Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage. 展开更多
关键词 Cotton seedling light-emitting diodes BIOMASS Palisade cell PHOTOSYNTHESIS
下载PDF
Finely regulated luminescent Ag-In-Ga-S quantum dots with green-red dual emission toward white light-emitting diodes
2
作者 Zhi Wu Leimeng Xu +1 位作者 Jindi Wang Jizhong Song 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第9期54-63,共10页
Ag-In-Ga-S(AIGS)quantum dots(QDs)have recently attracted great interests due to the outstanding optical properties and eco-friendly components,which are considered as an alternative replacement for toxic Pb-and Cd-bas... Ag-In-Ga-S(AIGS)quantum dots(QDs)have recently attracted great interests due to the outstanding optical properties and eco-friendly components,which are considered as an alternative replacement for toxic Pb-and Cd-based QDs.However,enormous attention has been paid to how to narrow their broadband spectra,ignoring the application advantages of the broadband emission.In this work,the AIGS QDs with controllable broad green-red dual-emission are first reported,which is achieved through adjusting the size distribution of QDs by controlling the nucleation and growth of AIGS crystals.Resultantly,the AIGS QDs exhibit broad dual-emission at green-and red-band evidenced by photoluminescence(PL)spectra,and the PL relative intensity and peak position can be finely adjusted.Furthermore,the dual-emission is the intrinsic characteristics from the difference in confinement effect of large particles and tiny particles confirmed by temperature-dependent PL spectra.Accordingly,the AIGS QDs(the size consists of 17 nm and 3.7 nm)with 530 nm and 630 nm emission could successfully be synthesized at 220°C.By combining the blue light-emitting diode(LED)chips and dual-emission AIGS QDs,the constructed white light-emitting devices(WLEDs)exhibit a continuous and broad spectrum like natural sunlight with the Commission Internationale de l’Eclairage(CIE)chromaticity coordinates of(0.33,0.31),a correlated color temperature(CCT)of 5425 K,color rendering index(CRI)of 90,and luminous efficacy of radiation(LER)of 129 lm/W,which indicates that the AIGS QDs have huge potential for lighting applications. 展开更多
关键词 quantum dots Ag-In-Ga-S dual emission white light-emitting diodes
下载PDF
Flexible perovskite light-emitting diodes for display applications and beyond
3
作者 Yongqi Zhang Shahbaz Ahmed Khan +1 位作者 Dongxiang Luo Guijun Li 《Journal of Semiconductors》 EI CAS CSCD 2024年第5期8-25,共18页
The flexible perovskite light-emitting diodes(FPeLEDs),which can be expediently integrated to portable and wearable devices,have shown great potential in various applications.The FPeLEDs inherit the unique optical pro... The flexible perovskite light-emitting diodes(FPeLEDs),which can be expediently integrated to portable and wearable devices,have shown great potential in various applications.The FPeLEDs inherit the unique optical properties of metal halide perovskites,such as tunable bandgap,narrow emission linewidth,high photoluminescence quantum yield,and particularly,the soft nature of lattice.At present,substantial efforts have been made for FPeLEDs with encouraging external quantum efficiency(EQE)of 24.5%.Herein,we summarize the recent progress in FPeLEDs,focusing on the strategy developed for perovskite emission layers and flexible electrodes to facilitate the optoelectrical and mechanical performance.In addition,we present relevant applications of FPeLEDs in displays and beyond.Finally,perspective toward the future development and applications of flexible PeLEDs are also discussed. 展开更多
关键词 metal halide perovskite flexible light-emitting diodes optical properties mechanical flexibility DISPLAY
下载PDF
Enhancing the Performance of Perovskite Light-Emitting Diodes via Synergistic Effect of Defect Passivation and Dielectric Screening
4
作者 Xuanchi Yu Jia Guo +11 位作者 Yulin Mao Chengwei Shan Fengshou Tian Bingheng Meng Zhaojin Wang Tianqi Zhang Aung Ko Ko Kyaw Shuming Chen Xiaowei Sun Kai Wang Rui Chen Guichuan Xing 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期244-256,共13页
Metal halide perovskites,particularly the quasi-two-dimensional perovskite subclass,have exhibited considerable potential for next-generation electroluminescent materials for lighting and display.Nevertheless,the pres... Metal halide perovskites,particularly the quasi-two-dimensional perovskite subclass,have exhibited considerable potential for next-generation electroluminescent materials for lighting and display.Nevertheless,the presence of defects within these perovskites has a substantial influence on the emission efficiency and durability of the devices.In this study,we revealed a synergistic passivation mechanism on perovskite films by using a dual-functional compound of potassium bromide.The dual functional potassium bromide on the one hand can passivate the defects of halide vacancies with bromine anions and,on the other hand,can screen the charged defects at the grain boundaries with potassium cations.This approach effectively reduces the probability of carriers quenching resulting from charged defects capture and consequently enhances the radiative recombination efficiency of perovskite thin films,leading to a significant enhancement of photoluminescence quantum yield to near-unity values(95%).Meanwhile,the potassium bromide treatment promoted the growth of homogeneous and smooth film,facilitating the charge carrier injection in the devices.Consequently,the perovskite light-emitting diodes based on this strategy achieve a maximum external quantum efficiency of~21%and maximum luminance of~60,000 cd m^(-2).This work provides a deeper insight into the passivation mechanism of ionic compound additives in perovskite with the solution method. 展开更多
关键词 Synergistic passivation strategy Defects passivation Dielectric screening Perovskite light-emitting diodes
下载PDF
Physico−mathematical model of the voltage−current characteristics of light-emitting diodes with quantum wells based on the Sah−Noyce−Shockley recombination mechanism
5
作者 Fedor I.Manyakhin Dmitry O.Varlamov +3 位作者 Vladimir P.Krylov Lyudmila O.Morketsova Arkady A.Skvortsov Vladimir K.Nikolaev 《Journal of Semiconductors》 EI CAS CSCD 2024年第8期25-33,共9页
Herein,a physical and mathematical model of the voltage−current characteristics of a p−n heterostructure with quantum wells(QWs)is prepared using the Sah−Noyce−Shockley(SNS)recombination mechanism to show the SNS reco... Herein,a physical and mathematical model of the voltage−current characteristics of a p−n heterostructure with quantum wells(QWs)is prepared using the Sah−Noyce−Shockley(SNS)recombination mechanism to show the SNS recombination rate of the correction function of the distribution of QWs in the space charge region of diode configuration.A comparison of the model voltage−current characteristics(VCCs)with the experimental ones reveals their adequacy.The technological parameters of the structure of the VCC model are determined experimentally using a nondestructive capacitive approach for determining the impurity distribution profile in the active region of the diode structure with a profile depth resolution of up to 10Å.The correction function in the expression of the recombination rate shows the possibility of determining the derivative of the VCCs of structures with QWs with a nonideality factor of up to 4. 展开更多
关键词 light-emitting diodes with quantum wells voltage−current relation nonideality factor recombination mechanism Sah−Noyce−Shockley model
下载PDF
Realization of high-efficiency AlGaN deep ultraviolet light-emitting diodes with polarization-induced doping of the p-AlGaN hole injection layer 被引量:1
6
作者 曹一伟 吕全江 +4 位作者 杨天鹏 米亭亭 王小文 刘伟 刘军林 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期690-696,共7页
We investigate the polarization-induced doping in the gradient variation of Al composition in the pAl_(0.75)Ga_(0.25)N/Al_xGa_(1-x)N hole injection layer(HIL)for deep ultraviolet light-emitting diodes(DUV-LEDs)with an... We investigate the polarization-induced doping in the gradient variation of Al composition in the pAl_(0.75)Ga_(0.25)N/Al_xGa_(1-x)N hole injection layer(HIL)for deep ultraviolet light-emitting diodes(DUV-LEDs)with an ultrathin p-GaN(4 nm)ohmic contact layer capable of emitting 277 nm.The experimental results show that the external quantum efficiency(EQE)and wall plug efficiency(WPE)of the structure graded from 0.75 to 0.55 in the HIL reach 5.49%and 5.04%,which are improved significantly by 182%and 209%,respectively,compared with the structure graded from 0.75 to 0.45,exhibiting a tremendous improvement.Both theoretical speculations and simulation results support that the larger the difference between 0.75 and x in the HIL,the higher the hole concentration that should be induced;thus,the DUV-LED has a higher internal quantum efficiency(IQE).Meanwhile,as the value of x decreases,the absorption of the DUV light emitted from the active region by the HIL is enhanced,reducing the light extraction efficiency(LEE).The IQE and LEE together affect the EQE performance of DUV-LEDs.To trade off the contradiction between the enhanced IQE and decreased LEE caused by the decrease in Al composition,the Al composition in the HIL was optimized through theoretical calculations and experiments. 展开更多
关键词 deep ultraviolet light-emitting diode(DUV-LED) polarization-induced doping ALGAN light extraction efficiency
下载PDF
Enhancing performance of inverted quantum-dot light-emitting diodes based on a solution-processed hole transport layer via ligand treatment
7
作者 Depeng Li Jingrui Ma +8 位作者 Wenbo Liu Guohong Xiang Xiangwei Qu Siqi Jia Mi Gu Jiahao Wei Pai Liu Kai Wang Xiaowei Sun 《Journal of Semiconductors》 EI CAS CSCD 2023年第9期68-74,共7页
The performance of inverted quantum-dot light-emitting diodes(QLEDs)based on solution-processed hole transport layers(HTLs)has been limited by the solvent-induced damage to the quantum dot(QD)layer during the spin-coa... The performance of inverted quantum-dot light-emitting diodes(QLEDs)based on solution-processed hole transport layers(HTLs)has been limited by the solvent-induced damage to the quantum dot(QD)layer during the spin-coating of the HTL.The lack of compatibility between the HTL’s solvent and the QD layer results in an uneven surface,which negatively impacts the overall device performance.In this work,we develop a novel method to solve this problem by modifying the QD film with 1,8-diaminooctane to improve the resistance of the QD layer for the HTL’s solvent.The uniform QD layer leads the inverted red QLED device to achieve a low turn-on voltage of 1.8 V,a high maximum luminance of 105500 cd/m2,and a remarkable maximum external quantum efficiency of 13.34%.This approach releases the considerable potential of HTL materials selection and offers a promising avenue for the development of high-performance inverted QLEDs. 展开更多
关键词 quantum dots quantum-dot light-emitting diodes inverted structure ligand treatment
下载PDF
Impedance spectroscopy for quantum dot light-emitting diodes
8
作者 Xiangwei Qu Xiaowei Sun 《Journal of Semiconductors》 EI CAS CSCD 2023年第9期26-38,共13页
Impedance spectroscopy has been increasingly employed in quantum dot light-emitting diodes(QLEDs)to investigate the charge dynamics and device physics.In this review,we introduce the mathematical basics of impedance s... Impedance spectroscopy has been increasingly employed in quantum dot light-emitting diodes(QLEDs)to investigate the charge dynamics and device physics.In this review,we introduce the mathematical basics of impedance spectroscopy that applied to QLEDs.In particular,we focus on the Nyquist plot,Mott-Schottky analysis,capacitance-frequency and capacitance-voltage characteristics,and the d C/d V measurement of the QLEDs.These impedance measurements can provide critical information on electrical parameters such as equivalent circuit models,characteristic time constants,charge injection and recombination points,and trap distribution of the QLEDs.However,this paper will also discuss the disadvantages and limitations of these measurements.Fundamentally,this review provides a deeper understanding of the device physics of QLEDs through the application of impedance spectroscopy,offering valuable insights into the analysis of performance loss and degradation mechanisms of QLEDs. 展开更多
关键词 quantum dot light-emitting diode impedance spectroscopy equivalent circuit model charge dynamics
下载PDF
Numerical Study of Optimization of Layer Thickness in Bilayer Organic Light-Emitting Diodes 被引量:3
9
作者 彭应全 张磊 张旭 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第5期454-460,共7页
A numerical model for bilayer organic light-emitting diodes (OLEDs) is developed under the basis of trapped charge limited conduction.The dependences of the current density on the layer thickness,trap properties and c... A numerical model for bilayer organic light-emitting diodes (OLEDs) is developed under the basis of trapped charge limited conduction.The dependences of the current density on the layer thickness,trap properties and carrier mobility of the hole transport layer (HTL) and emission layer (EML) in bilayer OLEDs of the structure anode/HTL/EML/cathode are numerically investigated.It is found that,for given values of the total thickness of organic layers,reduced depth of trap,total density of trap,and carrier mobility of HTL as well as EML,there exists an optimal thickness ratio of HTL to EML,by which a maximal quantum efficiency can be achieved.Through optimization of the thickness ratio,an enhancement of current density and quantum efficiency of as much as two orders of magnitude can be obtained.The dependences of the optimal thickness ratio to the characteristic trap energy,total density of trap and carrier mobility are numerically analyzed. 展开更多
关键词 organic light-emitting diodes BILAYER OPTIMIZATION
下载PDF
Proton‑Prompted Ligand Exchange to Achieve High‑Efficiency CsPbI_(3) Quantum Dot Light‑Emitting Diodes 被引量:1
10
作者 Yanming Li Ming Deng +2 位作者 Xuanyu Zhang Lei Qian Chaoyu Xiang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期53-62,共10页
CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improv... CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h. 展开更多
关键词 CsPbI_(3) perovskite quantum dots light-emitting diodes Ligand exchange Proton-prompted in-situ exchange
下载PDF
Recent Advances in Patterning Strategies for Full‑Color Perovskite Light‑Emitting Diodes
11
作者 Gwang Heon Lee Kiwook Kim +2 位作者 Yunho Kim Jiwoong Yang Moon Kee Choi 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期99-137,共39页
Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability,pure color emission with rem... Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability,pure color emission with remarkably narrow bandwidths,high quantum yield,and solution processability.Despite recent advances have pushed the luminance efficiency of monochromic perovskite light-emitting diodes(PeLEDs)to their theoretical limits,their current fabrication using the spincoating process poses limitations for fabrication of full-color displays.To integrate PeLEDs into full-color display panels,it is crucial to pattern red–green–blue(RGB)perovskite pixels,while mitigating issues such as cross-contamination and reductions in luminous efficiency.Herein,we present state-of-the-art patterning technologies for the development of full-color PeLEDs.First,we highlight recent advances in the development of efficient PeLEDs.Second,we discuss various patterning techniques of MPHs(i.e.,photolithography,inkjet printing,electron beam lithography and laserassisted lithography,electrohydrodynamic jet printing,thermal evaporation,and transfer printing)for fabrication of RGB pixelated displays.These patterning techniques can be classified into two distinct approaches:in situ crystallization patterning using perovskite precursors and patterning of colloidal perovskite nanocrystals.This review highlights advancements and limitations in patterning techniques for PeLEDs,paving the way for integrating PeLEDs into full-color panels. 展开更多
关键词 PEROVSKITE light-emitting diode Full-color display High-resolution patterning ELECTROLUMINESCENCE
下载PDF
A green-yellow emitting β-Sr_2SiO_4:Eu^(2+) phosphor for near ultraviolet chip white-light-emitting diode 被引量:20
12
作者 孙晓园 张家骅 +2 位作者 张霞 骆永石 王笑军 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第3期421-424,共4页
Sr2SiO4:xEu^2+ phosphors were synthesized through the solid-state reaction technique. The crystal phase of Sr2SiO4:xEu^2+ phosphor manipulated by Eu^2+ concentration was studied. The phase transited from β to α... Sr2SiO4:xEu^2+ phosphors were synthesized through the solid-state reaction technique. The crystal phase of Sr2SiO4:xEu^2+ phosphor manipulated by Eu^2+ concentration was studied. The phase transited from β to α' in Sr2SiO4:xEu^2+ phosphor with increasing europium concentration. The single β phase was formed as x≤005 and changed α' phase when x〉0.01. The emission spectrum of the β-Sr2SiO4:Eu^2+ phosphor consisted of a green-yellow broadband peaking at around 540 nm and a blue band at 470 nm under near ultraviolet excitation. The white LEDs by combining near ultraviolet chips with β-Sr2SiO4:Eu^2+ phosphors were fabricated. The luminous efficiency (15.7lm/W) was higher than α'-Sr2SiO4:Eu^2+ phosphor white LED. 展开更多
关键词 luminescence SILICATE light-emitting diode rare earths
下载PDF
Fabrication and Emission Properties of a n-ZnO/p-GaN Heterojunction Light-Emitting Diode
13
作者 周昕 顾书林 +7 位作者 朱顺明 叶建东 刘伟 刘松民 胡立群 郑有炓 张荣 施毅 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第2期249-253,共5页
We report the fabrication and characterization of light-emitting diodes based on n-ZnO/p-GaN heterojunctions. The n-type ZnO epilayer is deposited by metalorganic chemical vapor deposition (MOCVD) on a MOCVD grown M... We report the fabrication and characterization of light-emitting diodes based on n-ZnO/p-GaN heterojunctions. The n-type ZnO epilayer is deposited by metalorganic chemical vapor deposition (MOCVD) on a MOCVD grown Mg-doped p-GaN layer to form a p-n heterojunction. During the etching process, the relation between the etching depth and the etching time is linear in a HF and NH4 CI solution of a certain ratio. The etching rates of the SiO2 and ZnO are well controlled,which are essential for device fabrication. The current-voltage relationship of this heterojunction shows a diode-like rectifying behavior. In contrast to previous reports,electroluminescence (EL) emissions are observed by the naked eye at room temperature from the n-ZnO/p-GaN heterojunction under forward-and reverse-bias. The origins of these EL emissions are discussed in comparison with the pho- toluminescence spectra. 展开更多
关键词 ZnO/GaN heterojunction light-emitting diode metalorganic chemical vapor deposition etchingtechnology
下载PDF
Temperature effects on photoluminescence of YAG:Ce^(3+) phosphor and performance in white light-emitting diodes 被引量:21
14
作者 张艳芳 李岚 +1 位作者 张晓松 奚群 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第3期446-449,共4页
The well crystalline YAG:Ce^3+ phosphor was synthesized by sold-state method, and the temperature dependence of excitation and emission spectra of YAG:Ce^3+ phosphor were investigated in the temperature range from... The well crystalline YAG:Ce^3+ phosphor was synthesized by sold-state method, and the temperature dependence of excitation and emission spectra of YAG:Ce^3+ phosphor were investigated in the temperature range from room temperature to 573 K. With temperature increasing, it was noted that the emission intensity of as-repared phosphors decreased considerably more rapidly when pumped by 460 nm than by 340 nm. The temperature-intensity curves under different excitation wavelengths were obtained using an Arrhenius function, and the corresponding activation energies were also obtained respectively. Thus, the experimental phenomenon was discussed in terms of nonradiative decay rate. The effects of as-prepared phosphors on the performance of the white LED with changing temperature were also studied. 展开更多
关键词 white light-emitting diodes YAG: Ce^3+ activation energy nonradiative decay rate rare earths
下载PDF
Light-emitting diodes based on all-inorganic copper halide perovskite with self-trapped excitons 被引量:5
15
作者 Nian Liu Xue Zhao +4 位作者 Mengling Xia Guangda Niu Qingxun Guo Liang Gao Jiang Tang 《Journal of Semiconductors》 EI CAS CSCD 2020年第5期86-90,共5页
Light-emitting diodes based on lead halide perovskite have attracted great attention due to their outstanding performance.However,their application is plagued by the toxicity of Pb and the poor stability.Herein novel ... Light-emitting diodes based on lead halide perovskite have attracted great attention due to their outstanding performance.However,their application is plagued by the toxicity of Pb and the poor stability.Herein novel copper-based all inorganic perovskite CsCu2I3 with much enhanced stability has been reported with a potential photoluminescence quantum yield(PLQY)over 20%and self-trapped excitons(STE).By taking advantage of its extraordinary thermal stability,we successfully fabricate high-quality CsCu2I3 film through direct vacuum-based deposition(VBD)of CsCu2I3 powder.The resulting film shows almost the same PLQY with the synthesized powder,as well as excellent uniformity and stability.The perovskite light-emitting diodes(Pe-LED)based on the evaporated CsCu2I3 emitting layer achieve a luminescence of 10 cd/m2 and an external quantum efficiency(EQE)of 0.02%.To the best of our knowledge,this is the first CsCu2I3 Pe-LED fabricated by VBD with STE property,which offers a new avenue for lead-free Pe-LED. 展开更多
关键词 light-emitting diodes copper HALIDE PEROVSKITE vacuum-based evaporation self-trapped EXCITON
下载PDF
The strategies for preparing blue perovskite light-emitting diodes 被引量:4
16
作者 Jianxun Lu Zhanhua Wei 《Journal of Semiconductors》 EI CAS CSCD 2020年第5期26-33,共8页
Metal halide perovskites have attracted tremendous interest due to their excellent optical and electrical properties,and they find many promising applications in the optoelectronic fields of solar cells,light-emitting... Metal halide perovskites have attracted tremendous interest due to their excellent optical and electrical properties,and they find many promising applications in the optoelectronic fields of solar cells,light-emitting diodes,and photodetectors.Thanks to the contributions of international researchers,significant progress has been made for perovskite light-emitting diodes(Pero-LEDs).The external quantum efficiencies(EQEs)of Pero-LEDs with emission of green,red,and near-infrared have all exceeded 20%.However,the blue Pero-LEDs still lag due to the poor film quality and deficient device structure.Herein,we summarize the strategies for preparing blue-emitting perovskites and categorize them into two:compositional engineering and size controlling of the emitting units.The advantages and disadvantages of both strategies are discussed,and a perspective of preparing high-performance blue-emitting perovskite is proposed.The challenges and future directions of blue PeroLEDs fabrication are also discussed. 展开更多
关键词 PEROVSKITE BLUE light-emitting diodeS
下载PDF
Highly efficient emission and high-CRI warm white light-emitting diodes from ligand-modified CsPbBr_(3) quantum dots 被引量:7
17
作者 Dongdong Yan Shuangyi Zhao +2 位作者 Yubo Zhang Huaxin Wang Zhigang Zang 《Opto-Electronic Advances》 SCIE EI 2022年第1期35-48,共14页
All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have received great attention in white light emission because of their outstanding properties.However,their practical application is hindered by poor stability.Here... All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have received great attention in white light emission because of their outstanding properties.However,their practical application is hindered by poor stability.Herein,we propose a simple strategy to synthesize excellent stability and efficient emission of CsPbBr_(3) QDs by using 2-hexyldecanoic acid(DA)as a ligand to replace the regular oleic acid(OA)ligand.Thanks to the strong binding energy between DA ligand and QDs,the modified QDs not only show a high photoluminescence quantum yield(PLQY)of 96%but also exhibit high stability against ethanol and water.Thereby warm white light-emitting diodes(WLEDs)are constructed by combining lig-and modified CsPbBr_(3) QDs with red AgInZnS QDs on blue emitting InGaN chips,exhibiting a color rendering index of 93,a power efficiency of 64.8 lm/W,a CIE coordinate of(0.44,0.42)and correlated color temperature value of 3018 K.In ad-dition,WLEDs based on ligand modified CsPbBr_(3) QDs also exhibit better thermal performance than that of WLEDs based on the regular CsPbBr_(3) QDs.The combination of improved efficiency and better thermal stability with high color quality indicates that the modified CsPbBr_(3) QDs are ideal for WLEDs application. 展开更多
关键词 CsPbBr_(3)quantum dots ligand modification stability efficiency white light-emitting diodes
下载PDF
Simulation study of blue InGaN multiple quantum well light-emitting diodes with different hole injection layers 被引量:4
18
作者 仵乐娟 李述体 +8 位作者 刘超 王海龙 卢太平 张康 肖国伟 周玉刚 郑树文 尹以安 杨孝东 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期583-587,共5页
InGaN-based light-emitting diodes with p-GaN and p-A1GaN hole injection layers are numerically studied using the APSYS simulation software. The simulation results indicate that light-emitting diodes with p-A1GaN hole ... InGaN-based light-emitting diodes with p-GaN and p-A1GaN hole injection layers are numerically studied using the APSYS simulation software. The simulation results indicate that light-emitting diodes with p-A1GaN hole injection layers show superior optical and electrical performance, such as an increase in light output power, a reduction in current leakage and alleviation of efficiency droop. These improvements can be attributed to the p-A1GaN serving as hole injection layers, which can alleviate the band bending induced by the polarization field, thereby improving both the hole injection efficiency and the electron blocking efficiency. 展开更多
关键词 GaN-based light-emitting diodes hole injection layer injection efficiency
下载PDF
Very-High Color Rendering Index Hybrid White Organic Light-Emitting Diodes with Double Emitting Nanolayers 被引量:4
19
作者 Baiquan Liu Miao Xu +6 位作者 Lei Wang Hong Tao Yueju Su Dongyu Gao Linfeng Lan Jianhua Zou Junbiao Peng 《Nano-Micro Letters》 SCIE EI CAS 2014年第4期335-339,共5页
A very-high color rendering index white organic light-emitting diode(WOLED) based on a simple structure was successfully fabricated. The optimized device exhibits a maximum total efficiency of 13.1 and 5.4 lm/W at 1,0... A very-high color rendering index white organic light-emitting diode(WOLED) based on a simple structure was successfully fabricated. The optimized device exhibits a maximum total efficiency of 13.1 and 5.4 lm/W at 1,000 cd/m2. A peak color rendering index of 90 and a relatively stable color during a wide range of luminance were obtained. In addition, it was demonstrated that the 4,40,400-tri(9-carbazoyl) triphenylamine host influenced strongly the performance of this WOLED.These results may be beneficial to the design of both material and device architecture for high-performance WOLED. 展开更多
关键词 White light HYBRID Color rendering index Organic light-emitting diodes Double emitting nanolayers
下载PDF
Performance improvement of AlGaN-based deep ultraviolet light-emitting diodes with double electron blocking layers 被引量:4
20
作者 张诚 孙慧卿 +4 位作者 李旭娜 孙浩 范宣聪 张柱定 郭志友 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期538-543,共6页
The AlGaN-based deep ultraviolet light-emitting diodes(LED) with double electron blocking layers(d-EBLs) on both sides of the active region are investigated theoretically. They possess many excellent performances ... The AlGaN-based deep ultraviolet light-emitting diodes(LED) with double electron blocking layers(d-EBLs) on both sides of the active region are investigated theoretically. They possess many excellent performances compared with the conventional structure with only a single electron blocking layer, such as a higher recombination rate, improved light output power and internal quantum efficiency(IQE). The reasons can be concluded as follows. On the one hand, the weakened electrostatic field within the quantum wells(QWs) enhances the electron–hole spatial overlap in QWs, and therefore increases the probability of radioactive recombination. On the other hand, the added n-AlGaN layer can not only prevent holes from overflowing into the n-side region but also act as another electron source, providing more electrons. 展开更多
关键词 double electron blocking layers ultraviolet light-emitting diodes n-A1GaN electrostatic field
下载PDF
上一页 1 2 26 下一页 到第
使用帮助 返回顶部