The increasing demand for flexible displays and wearable electronics has driven extensive efforts to develop stretchable organic lightemitting diodes(OLEDs).A critical challenge in this field is the creation of emissi...The increasing demand for flexible displays and wearable electronics has driven extensive efforts to develop stretchable organic lightemitting diodes(OLEDs).A critical challenge in this field is the creation of emissive layers that combine high efficiency with mechanical robustness.Thermally activated delayed fluorescence(TADF)materials have attracted significant attention as third-generation emitters capable of achieving 100%internal quantum efficiency;however,their application in stretchable OLEDs has been limited.In this study,we propose an elastomer doping strategy.Polyurethane(PU)is incorporated into TADF polymers to improve their mechanical flexibility while maintaining a high luminescent efficiency.The resulting composite films exhibited excellent TADF characteristics and remarkable stretchability(75%).OLEDs fabricated from these materials achieved a maximum external quantum efficiency(EQE)of 14.26%and a peak luminance of 73570 cd·m^(-2),with the PUdoped devices showing a significantly suppressed efficiency roll-off.Additionally,a fully stretchable OLED architecture was designed and operated under tensile strain to maintain stable electroluminescent performance.These results demonstrate that elastomer doping is an effective strategy for balancing the mechanical compliance with optoelectronic performance,offering a promising pathway for the development of high-performance stretchable OLEDs for flexible electronics.展开更多
Unlike conventional electrochromic devices,Zinc anode-based electrochromic devices(ZECDs)ensure excellent charge balance between the electrochromic layer and Zn anode during the coloring/bleaching by reversible metal ...Unlike conventional electrochromic devices,Zinc anode-based electrochromic devices(ZECDs)ensure excellent charge balance between the electrochromic layer and Zn anode during the coloring/bleaching by reversible metal deposition/stripping on the Zn anode.Meanwhile,the inherent potential difference between the metal anode and the electrochromic layer can drive the spontaneous coloration/bleaching of ZECDs,featuring energy retrieval functionality.This review discusses the working mechanisms,performance indexes of ZECDs,and the impact of material selection on ZECD performance.Furthermore,we comprehensively summarize the latest research progress of ZECDs in energy storage,smart windows,and multicolor displays.We argue that using high-transparency zinc mesh,additive manufacturing processes,and self-healing electrochromic materials can significantly advance the commercialization of large-area ZECDs.Finally,“electrode-free”device structures,renewable or replaceable electrolytes,and strategies to suppress zinc dendrites are prospected to overcome cost-effectiveness and lifespan issues of ZECDs.This review aims at enabling more efficient and advanced ZECDs for multifunctional applications.展开更多
With the global push for energy conservation and the rapid development of low-power,flexible and wearable optical displays,the demand for electrochromic technology has surged.Gel polymer electrolytes(GPEs),a crucial c...With the global push for energy conservation and the rapid development of low-power,flexible and wearable optical displays,the demand for electrochromic technology has surged.Gel polymer electrolytes(GPEs),a crucial component of electrochromic devices(ECDs),show great promise in applications.This is attributed to their efficient ion-transport capabilities,excellent mechanical properties and strong adhesion.All of these characteristics are conducive to enhancing the safety of the devices,streamlining the packaging process,significantly improving the electrochromic performance of ECDs and boosting their commercial application potential.This review provides a comprehensive overview of GPEs for ECDs,focusing on their basic designs,functional modifications and practical applications.Firstly,this review outlines the fundamental design of GPEs for ECDs,encompassing key performance index,classification,gelation mechanism and preparation methods.Building on this foundation,it provides an in-depth discussion of functionalized GPEs developed to enhance device performance or expand functionality,including electrochromic,temperature-responsive,photo-responsive and stretchable self-healing GPE.Furthermore,the integration of GPEs into various ECD applications,including smart windows,displays,energy storage devices and wearable electronic,are summarized to highlight the advantages that the design of GPEs brings to the practical application of ECDs.Finally,based on the summary of GPEs employed for ECDs,the challenges and development expectations in this direction were indicated.展开更多
近年来随着手机薄型化趋势的发展以及对可靠性要求的提高,OLED(Organic Light-Emitting Diode)屏幕孔区出现彩虹纹现象的比例有一定的上升。本文定性、定量地分析了OLED屏幕孔区出现彩虹纹现象的原因,并基于此,建立了一套相对完备的可...近年来随着手机薄型化趋势的发展以及对可靠性要求的提高,OLED(Organic Light-Emitting Diode)屏幕孔区出现彩虹纹现象的比例有一定的上升。本文定性、定量地分析了OLED屏幕孔区出现彩虹纹现象的原因,并基于此,建立了一套相对完备的可以相互交叉印证结果的多维度分析测试方法。对薄膜封装(Thin Film Encapsulation,TFE)膜层结构成分的进一步优化,可以最大限度地降低可靠性测试后出现与孔区彩虹纹相关的暗斑风险。通过裂片,分析了高温高湿实验条件下孔区发生彩虹纹的区域和位置;并以透射电子显微镜(Transmission Electron Microscope,TEM)、飞行时间二次离子质谱(Time of Flight Secondary Ion Mass Spectrometry,TOF-SIMS)和X射线光电子能谱(X-ray Photoelectron Spectroscopy,XPS)系统分析了孔区产生现象的原因。实验结果表明,CVD1(Chemical Vapor Deposition 1)中SiON在高温高湿条件下,会逐步向SiO膜层转化。TEM和TOF-SIMS的结果表明,被氧化后膜层的含氮量小于2%;XPS分峰结果显示,CVD1-2表面的SiON几乎全部转化为SiO膜层。通过将TFE中CVD1-1的SiON膜层折光率从1.72提升为1.76,CVD1-1的SiON膜层被氧化的深度下降了70%。该分析方法的建立不仅解释了孔区CVD膜层被氧化后生成的SiO是造成出现彩虹纹现象的原因,而且提出了彩虹纹区域对OLED面板孔区可靠性的影响。该方案策略为OLED显示未来在车载、IT(Information Technology)、广告牌等具有更高可靠性要求领域的应用提供了相应的解决思路。展开更多
Electrodeposited organic light-emitting diode(OLED)technology requires a spin-coating-free hole-injection layer that simultaneously provides smooth surface morphology,stable energy levels,and compatibility with high-r...Electrodeposited organic light-emitting diode(OLED)technology requires a spin-coating-free hole-injection layer that simultaneously provides smooth surface morphology,stable energy levels,and compatibility with high-resolution pixel architectures.In this study,electropolymerization of 3,4-ethylenedioxythiophene(EDOT)in poly(styrene sulfonate)(PSS-)surfactant-solubilized colloidal media is shown to afford poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)films with robust surface uniformity and stable energy levels suitable for application as hole-injection layers in OLEDs.Systematic investigation reveals that the hole-injection properties of these films are governed primarily by the colloidal chemistry of EDOT/PSS-surfactant-solubilized systems,rather than by conventional electrochemical parameters.This colloidal regulation modulates the film work function over a practically useful range.Incorporation of optimized films into OLEDs leads to enhanced hole injection and improved device performance,with external quantum efficiency increasing from 2.2%to 7.4%and minimal roll-off.Overall,this work demonstrates a feasible example of realizing spin-coating-free hole-injection layers,offering a potential direction for the development of electrodeposited injection layers for OLEDs.展开更多
The development of non-corrosive and efficient anode interlayers(AILs)is pivotal for advancing highperformance organic optoelectronic devices.Conventional materials such as PEDOT:PSS,though widely adopted,suffer from ...The development of non-corrosive and efficient anode interlayers(AILs)is pivotal for advancing highperformance organic optoelectronic devices.Conventional materials such as PEDOT:PSS,though widely adopted,suffer from significant limitations including acidity,corrosion,and poor device stability.Herein,we propose a novel molecular design strategy by introducing p-πconjugation into a p Hneutral conjugated polyelectrolyte(CPE)(PIDT-T)to simultaneously enhance work function(WF)and electrical conductivity.Through doping with polyoxometalate(POM),the optimized PIDT-T:POM achieves a high WF of 4.85 e V,conductivity of 7.25×10^(-3)S cm^(-1),and>98%optical transmittance.In organic solar cells(OSCs),PIDT-T:POM delivers a power conversion efficiency(PCE)of 19.04%,outperforming PEDOT:PSS-based counterparts(18.52%)and representing one of the highest PCEs reported for devices utilizing non-acidic AILs.Moreover,organic light-emitting diodes(OLEDs)incorporating PIDTT:POM exhibit a remarkable reduction in turn-on voltage(from 5.8 to 3.0 V)and enhanced luminous efficiency,demonstrating its dual functionality for both OSCs and OLEDs.These findings establish p-πconjugated polyelectrolytes as a powerful molecular platform for next-generation,high-efficiency,and corrosion-free organic optoelectronic applications.展开更多
Hybrid local and charge-transfer(HLCT)states offer an effective pathway for developing efficient blue organic light-emitting diodes(OLEDs).In HLCT emitters,locally excited(LE)states enhance radiative transitions and p...Hybrid local and charge-transfer(HLCT)states offer an effective pathway for developing efficient blue organic light-emitting diodes(OLEDs).In HLCT emitters,locally excited(LE)states enhance radiative transitions and photoluminescence quantum yield,while charge-transfer(CT)states facilitate exciton harvesting via reverse intersystem crossing.Here,we propose an HLCT-oriented molecular design strategy to achieve efficient blue emission.Pyrene-imidazole(PyI)was employed as a weak donor and linked to benzoxazole(BO)acceptors through para-and meta-benzene π-bridges,affording two D-π-A molecules,p-PyI-PBO and m-PyI-PBO.The π-bridges strengthen conjugation and stabilize the HLCT state,while the para-to-meta linkage transforms a linear"I-shaped"geometry into a twisted"V-shaped"configuration,shortening conjugation and modulating donoracceptor coupling.This structural regulation produces a more balanced LE/CT distribution,suppressing excessive LE character while retaining sufficient CT contribution for efficient exciton utilization.As a result,m-PyI-PBO exhibits more favorable excited-state properties and delivers efficient blue emission with high color purity.Benefiting from its balanced HLCT characteristics and robust photophysical and thermal stability,the nondoped OLED based on m-PyI-PBO shows bright blue emission with CIE coordinates of(0.15,0.13),a maximum external quantum efficiency(EQE_(max))of 9.52%,and a low roll-off of 3.36%at 1000 cd^(-2).The doped device further emits deep blue with CIE coordinates of(0.16,0.06),close to the European Broadcasting Union standard,and achieves an EQE_(max)of 13.22%with an exciton utilization efficiency of 79.72%.This work demonstrates thatπ-bridge engineering combined with meta-linkage is an effective strategy for constructing efficient HLCT-type blue emitters.展开更多
基金supported by the National Natural Science Foundation of China(Nos.T2441002,22525506,U24A20137,and U22A6002)Strategic Priority Research Program of CAS(No.XDB0520101)+1 种基金National Key R&D Program of China(No.2023YFB3609000)CAS Project for Young Scientists in Basic Research(No.YSBR-053)。
文摘The increasing demand for flexible displays and wearable electronics has driven extensive efforts to develop stretchable organic lightemitting diodes(OLEDs).A critical challenge in this field is the creation of emissive layers that combine high efficiency with mechanical robustness.Thermally activated delayed fluorescence(TADF)materials have attracted significant attention as third-generation emitters capable of achieving 100%internal quantum efficiency;however,their application in stretchable OLEDs has been limited.In this study,we propose an elastomer doping strategy.Polyurethane(PU)is incorporated into TADF polymers to improve their mechanical flexibility while maintaining a high luminescent efficiency.The resulting composite films exhibited excellent TADF characteristics and remarkable stretchability(75%).OLEDs fabricated from these materials achieved a maximum external quantum efficiency(EQE)of 14.26%and a peak luminance of 73570 cd·m^(-2),with the PUdoped devices showing a significantly suppressed efficiency roll-off.Additionally,a fully stretchable OLED architecture was designed and operated under tensile strain to maintain stable electroluminescent performance.These results demonstrate that elastomer doping is an effective strategy for balancing the mechanical compliance with optoelectronic performance,offering a promising pathway for the development of high-performance stretchable OLEDs for flexible electronics.
基金supports from the National Natural Science Foundation of China(62105185,52202320)the“Qilu Young Scholar”program(62460082163097)of Shandong University,open foundation of the State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization(2023P4FZG08A)+1 种基金Fundamental Research Funds for the Central Universities(No.862201013153)Shandong Excellent Young Scientists Fund Program(Overseas)(2023HWYQ-060).
文摘Unlike conventional electrochromic devices,Zinc anode-based electrochromic devices(ZECDs)ensure excellent charge balance between the electrochromic layer and Zn anode during the coloring/bleaching by reversible metal deposition/stripping on the Zn anode.Meanwhile,the inherent potential difference between the metal anode and the electrochromic layer can drive the spontaneous coloration/bleaching of ZECDs,featuring energy retrieval functionality.This review discusses the working mechanisms,performance indexes of ZECDs,and the impact of material selection on ZECD performance.Furthermore,we comprehensively summarize the latest research progress of ZECDs in energy storage,smart windows,and multicolor displays.We argue that using high-transparency zinc mesh,additive manufacturing processes,and self-healing electrochromic materials can significantly advance the commercialization of large-area ZECDs.Finally,“electrode-free”device structures,renewable or replaceable electrolytes,and strategies to suppress zinc dendrites are prospected to overcome cost-effectiveness and lifespan issues of ZECDs.This review aims at enabling more efficient and advanced ZECDs for multifunctional applications.
基金supported by the National Natural Science Foundation of China(52103299)。
文摘With the global push for energy conservation and the rapid development of low-power,flexible and wearable optical displays,the demand for electrochromic technology has surged.Gel polymer electrolytes(GPEs),a crucial component of electrochromic devices(ECDs),show great promise in applications.This is attributed to their efficient ion-transport capabilities,excellent mechanical properties and strong adhesion.All of these characteristics are conducive to enhancing the safety of the devices,streamlining the packaging process,significantly improving the electrochromic performance of ECDs and boosting their commercial application potential.This review provides a comprehensive overview of GPEs for ECDs,focusing on their basic designs,functional modifications and practical applications.Firstly,this review outlines the fundamental design of GPEs for ECDs,encompassing key performance index,classification,gelation mechanism and preparation methods.Building on this foundation,it provides an in-depth discussion of functionalized GPEs developed to enhance device performance or expand functionality,including electrochromic,temperature-responsive,photo-responsive and stretchable self-healing GPE.Furthermore,the integration of GPEs into various ECD applications,including smart windows,displays,energy storage devices and wearable electronic,are summarized to highlight the advantages that the design of GPEs brings to the practical application of ECDs.Finally,based on the summary of GPEs employed for ECDs,the challenges and development expectations in this direction were indicated.
文摘近年来随着手机薄型化趋势的发展以及对可靠性要求的提高,OLED(Organic Light-Emitting Diode)屏幕孔区出现彩虹纹现象的比例有一定的上升。本文定性、定量地分析了OLED屏幕孔区出现彩虹纹现象的原因,并基于此,建立了一套相对完备的可以相互交叉印证结果的多维度分析测试方法。对薄膜封装(Thin Film Encapsulation,TFE)膜层结构成分的进一步优化,可以最大限度地降低可靠性测试后出现与孔区彩虹纹相关的暗斑风险。通过裂片,分析了高温高湿实验条件下孔区发生彩虹纹的区域和位置;并以透射电子显微镜(Transmission Electron Microscope,TEM)、飞行时间二次离子质谱(Time of Flight Secondary Ion Mass Spectrometry,TOF-SIMS)和X射线光电子能谱(X-ray Photoelectron Spectroscopy,XPS)系统分析了孔区产生现象的原因。实验结果表明,CVD1(Chemical Vapor Deposition 1)中SiON在高温高湿条件下,会逐步向SiO膜层转化。TEM和TOF-SIMS的结果表明,被氧化后膜层的含氮量小于2%;XPS分峰结果显示,CVD1-2表面的SiON几乎全部转化为SiO膜层。通过将TFE中CVD1-1的SiON膜层折光率从1.72提升为1.76,CVD1-1的SiON膜层被氧化的深度下降了70%。该分析方法的建立不仅解释了孔区CVD膜层被氧化后生成的SiO是造成出现彩虹纹现象的原因,而且提出了彩虹纹区域对OLED面板孔区可靠性的影响。该方案策略为OLED显示未来在车载、IT(Information Technology)、广告牌等具有更高可靠性要求领域的应用提供了相应的解决思路。
文摘量子点发光二极管(Quantum Dot Light-emitting Diode,QLED)具有卓越的性能,如高色纯度、宽色域和可调节的发射波长。这些独特的优点使其成为下一代显示器和固态照明领域的有力竞争者。本文系统地分析了长寿命QLED器件的设计策略,从量子点发光层(Emitting Layer,EML)、电子传输层(Electron Transport Layer,ETL)、空穴传输层(Hole Transport Layer,HTL)等3个核心功能层梳理长寿命QLED器件的共性特征和规律,为后续蓝光QLED器件和更多量子点体系QLED器件寿命的提升提供有益的思路,对长寿命QLED技术的发展提出展望。
基金supported by the National Key R&D Program of China(No.2020YFA0714604)the Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates(No.2023B1212060003)+1 种基金the SSL Sci-tech Commissioner Program(No.20234383-01KCJ-G)the National Natural Science Foundation of China(No.92463310)。
文摘Electrodeposited organic light-emitting diode(OLED)technology requires a spin-coating-free hole-injection layer that simultaneously provides smooth surface morphology,stable energy levels,and compatibility with high-resolution pixel architectures.In this study,electropolymerization of 3,4-ethylenedioxythiophene(EDOT)in poly(styrene sulfonate)(PSS-)surfactant-solubilized colloidal media is shown to afford poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)films with robust surface uniformity and stable energy levels suitable for application as hole-injection layers in OLEDs.Systematic investigation reveals that the hole-injection properties of these films are governed primarily by the colloidal chemistry of EDOT/PSS-surfactant-solubilized systems,rather than by conventional electrochemical parameters.This colloidal regulation modulates the film work function over a practically useful range.Incorporation of optimized films into OLEDs leads to enhanced hole injection and improved device performance,with external quantum efficiency increasing from 2.2%to 7.4%and minimal roll-off.Overall,this work demonstrates a feasible example of realizing spin-coating-free hole-injection layers,offering a potential direction for the development of electrodeposited injection layers for OLEDs.
基金the financial support from the Beijing Municipal Science&Technology Commission(2242013)。
文摘The development of non-corrosive and efficient anode interlayers(AILs)is pivotal for advancing highperformance organic optoelectronic devices.Conventional materials such as PEDOT:PSS,though widely adopted,suffer from significant limitations including acidity,corrosion,and poor device stability.Herein,we propose a novel molecular design strategy by introducing p-πconjugation into a p Hneutral conjugated polyelectrolyte(CPE)(PIDT-T)to simultaneously enhance work function(WF)and electrical conductivity.Through doping with polyoxometalate(POM),the optimized PIDT-T:POM achieves a high WF of 4.85 e V,conductivity of 7.25×10^(-3)S cm^(-1),and>98%optical transmittance.In organic solar cells(OSCs),PIDT-T:POM delivers a power conversion efficiency(PCE)of 19.04%,outperforming PEDOT:PSS-based counterparts(18.52%)and representing one of the highest PCEs reported for devices utilizing non-acidic AILs.Moreover,organic light-emitting diodes(OLEDs)incorporating PIDTT:POM exhibit a remarkable reduction in turn-on voltage(from 5.8 to 3.0 V)and enhanced luminous efficiency,demonstrating its dual functionality for both OSCs and OLEDs.These findings establish p-πconjugated polyelectrolytes as a powerful molecular platform for next-generation,high-efficiency,and corrosion-free organic optoelectronic applications.
基金supported by the Natural Science Foundation of Hei-longjiang Province(No.YQ2023B001)the"Academic Backbone"Project of Northeast Agricultural University(No.20xG19).
文摘Hybrid local and charge-transfer(HLCT)states offer an effective pathway for developing efficient blue organic light-emitting diodes(OLEDs).In HLCT emitters,locally excited(LE)states enhance radiative transitions and photoluminescence quantum yield,while charge-transfer(CT)states facilitate exciton harvesting via reverse intersystem crossing.Here,we propose an HLCT-oriented molecular design strategy to achieve efficient blue emission.Pyrene-imidazole(PyI)was employed as a weak donor and linked to benzoxazole(BO)acceptors through para-and meta-benzene π-bridges,affording two D-π-A molecules,p-PyI-PBO and m-PyI-PBO.The π-bridges strengthen conjugation and stabilize the HLCT state,while the para-to-meta linkage transforms a linear"I-shaped"geometry into a twisted"V-shaped"configuration,shortening conjugation and modulating donoracceptor coupling.This structural regulation produces a more balanced LE/CT distribution,suppressing excessive LE character while retaining sufficient CT contribution for efficient exciton utilization.As a result,m-PyI-PBO exhibits more favorable excited-state properties and delivers efficient blue emission with high color purity.Benefiting from its balanced HLCT characteristics and robust photophysical and thermal stability,the nondoped OLED based on m-PyI-PBO shows bright blue emission with CIE coordinates of(0.15,0.13),a maximum external quantum efficiency(EQE_(max))of 9.52%,and a low roll-off of 3.36%at 1000 cd^(-2).The doped device further emits deep blue with CIE coordinates of(0.16,0.06),close to the European Broadcasting Union standard,and achieves an EQE_(max)of 13.22%with an exciton utilization efficiency of 79.72%.This work demonstrates thatπ-bridge engineering combined with meta-linkage is an effective strategy for constructing efficient HLCT-type blue emitters.
