This study aims to enhance the optical stability of CdSe/ZnS green quantum dots(QDs) in display applications by addressing their susceptibility to environmental factors, including moisture, oxygen, and incompatibility with polymers, which may result in ligand desorption and a decrease in luminescence efficiency. The more effective protection strategies were explored to improve their photostability and humid-thermal stability under blue light excitation. The QD@SiO2 coating layer was prepared on the surface of green QDs by microemulsion method and Stober method, respectively. The QD@AlOx coating layer was prepared by sol-gel method. Then, the morphology, structure, and photoluminescence(PL) stability of the prepared QD@SiO2 and QD@AlO(x )were characterized. Finally, these two types of QD composite were respectively fabricated into green QD diffuser plates, which were subjected to aging tests under blue light (200 mW/cm(2)) and humid-thermal blue light conditions (50 degrees C/90 degrees a RH, 5 000 cd/m(2) blue light) to assess their photostability and humid-thermal stability in display applications. Experimental results demonstrated that both the prepared QD@SiO2 and QD@AlOx exhibited excellent optical stability under blue light excitation. Among them, the AlOx protective layer has better stability in the humid-thermal aging tests due to its smaller specific surface area and pore volume, and can effectively suppress the attenuation of the photoluminescence efficiency of QDs. This study effectively enhanced the environmental stability of green QDs through two surface coating methods, meeting the essential requirements of display devices for high photostability and humid-thermal stability tolerance. It provides a theoretical basis and practical solution for the development of high-performance QD devices.
As a carrier of visual information,displays play an indispensable role in an increasingly digital and intelligent life.Quantum dot light-emitting diodes(QLEDs)are poised to lead the next generation of display technology with their outstanding performance,and are expected to reshape the international display panel market landscape.However,the practical application of QLED devices are still subject to some constraints,for example,the luminous performance and lifetime have not yet met the requirements for commercial application.In order to prepare high-performance QLEDs,it is a common method to modify the interface of each functional layer.Based on this,the review summarizes the research progress of QLEDs interface modification from many aspects,and analyses in detail the mechanism of interface modification and its effect on the performance of QLEDs.Finally,the shortcomings in the development of QLEDs are pointed out,and the future development directions of QLEDs are proposed.This review is expected to provide valuable reference for the academic research and industrialization of QLEDs.
Quantum dot light-emitting diodes(QLEDs) exhibit outstanding properties, such as high color purity, wide color gamut, and tunable emission wavelengths. These advantages make them strong competitors in the fields of next-generation displays and solid-state lighting. There are three core functional layers in QLED: the quantum dot Emitting Layer(EML), Electron Transport Layer(ETL), and Hole Transport Layer(HTL), which are of great significance for the lifetime of QLEDs. In this review, we summarize the common characteristics and patterns of long-lifetime QLED devices from researches about these three functional layers. We systematically analyze the design strategies for long-lifetime QLED devices. This paper provides valuable insights for subsequent lifetime research on blue QLED devices and QLED devices based on more quantum dot systems, and presents an outlook on the development of long-lifetime QLED technology.
Colloidal quantum dots (QDs) are recognized as the key luminescent materials for next-generation display and lighting technologies, owing to their unique size-dependent luminescent properties, high color purity, and high photoluminescent quantum yield (PLQY). Among various QDs, indium phosphide (InP) quantum dots show particular promise for future displays and lighting applications due to their environmentally benign characteristics, broad spectral tunability, and cost-effective solution processability. This article provides a systematic review of recent advances in green-emitting InP QDs, highlighting three critical breakthroughs. First, in the aspect of chemical synthesis, precise regulation of reaction kinetics has enabled the fabrication of green-emitting InP core particles with uniform size and high crystallinity. Second, in terms of surface passivation, both ionic and shell passivation have been implemented to effectively suppress surface defect states in the core, leading to a significant improvement in the PLQY. Third, in terms of ligand engineering, the modification of surface ligands has yielded stable InP QDs with suitably aligned energy levels. Furthermore, the paper presents an outlook on their future development directions.
Electron-hole injection imbalance caused by slow hole injection is one of the major factors limiting the performance improvement of multinary copper chalcogenide quantum dot light-emitting diodes(QLEDs). This study designed a strategy to modify poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT & ratio;PSS) using a nafion perfluorinated resin(PFI). Taking advantage of the self-assembly property of PFI, a hole injection layer (PFI-PEDOT & ratio;PSS) with a gradient energy level was constructed. Single hole-transporting devices further demonstrate that the PFI-PEDOT & ratio;PSS hole injection layer can effectively reduce the hole injection barrier and enhance hole injection efficiency, thereby improving device performance. Finally, the peak external quantum efficiency of the electroluminescent devices fabricated with PFI-PEDOT & ratio; PSS as the hole injection layer and Cu-In-Zn-S quantum dots as the emitting layer reached 4. 7%, which was 2. 2 times that of the PEDOT & ratio; PSS-based devices. The results indicate that this modification strategy of incorporating PFI into the PEDOT & ratio; PSS hole injection layer can effectively enhance the performance of Cu-In-Zn-S-based QLEDs, and also lays an important research foundation for the subsequent industrial application of environmentally friendly QLEDs.
The new generation of light-emitting devices requires luminescent materials to possess advantages such as high photoluminescence quantum yield, broadly tunable spectra, excellent solution processability, readily accessible raw materials, and environmental friendliness. However, high-performance lead halide perovskites and cadmium-based quantum dots currently pose threats to human health, necessitating the development of low-toxic luminescent materials with comparable performance. Coordinated copper halides represent a class of luminescent materials for novel display and lighting applications. Among lead-and cadmium-free metal halide emitters, they demonstrate leading luminescence properties, positioning them as strong competitors to lead halide perovskites and cadmium-based quantum dots in the field of light-emitting devices. In recent years, significant progress has been made in the research of coordination-type copper(I) halide luminescent materials. Researchers have designed and synthesized a series of coordinated copper halides with diverse ligands and inorganic units, achieving tunable photoluminescence across the visible spectrum and photoluminescence quantum yields approaching unity. Electroluminescent devices based on coordinated copper halides have realized external quantum efficiencies up to 23. 5% and maximum luminance exceeding 60 000 cd & centerdot;m-2, demonstrating considerable application potential. This review summarizes the crystal structures, synthesis methods, and photophysical properties of coordinated copper halides, and discusses their advancements in electroluminescent devices. Finally, the structures, properties, and applications of coordinated copper halides are concluded and future perspectives are provided.
Quantum dots(QDs) have captured the imagination of both industry and academia, owing to their extraordinary optical properties-high fluorescence quantum yield, broad absorption bandwidth, narrow emission peaks, and excellent optical stability. These remarkable traits have positioned QDs as a cornerstone of innovation in the realm of cutting-edge display technologies. However, their journey from laboratory promise to real-world application is not without challenges. In practical scenarios, the stability of QDs is inevitably impaired by environmental factors, such as oxygen, water, light, and heat. This review aims to address that challenge, offering a beacon of insight and a roadmap of strategies to bolster the environmental resilience of QDs. Through a detailed exploration of the factors influencing their stability, we outline a critical pathway: light and temperature act as accelerators, hastening the degradation processes driven by water and oxygen. Furthermore, we illuminate the intricate web of relationships within the QD system, revealing how its internal components are interlinked. Outstanding stability, we argue, demands a comprehensive approach-one that embraces the entirety of the QD framework, including QD structure, inorganic surface, organic ligands, and the corresponding interfaces with solvents (medium). To bring this vision to life, we spotlight practical examples, such as QD films and diffusion plates, showcasing their transformative role in display technologies. We also define the real-world conditions they must endure, including high temperatures and low relative humidity, grounding our analysis in the realities of application. Far from a mere technical discourse, this review is an invitation-to researchers, innovators, and curious minds alike-to join in unlocking the full potential of QDs. By fortifying their environmental stability, we pave the way for a dazzling future in display technology, one where quantum dots shine brighter than ever before.
Lead halide perovskite nanocrystals have garnered significant interest due to their exceptional optical properties. However, their poor environmental stability and the toxicity of conventional synthetic methods continue to impede practical applications. In this study, we report a novel ultrasound-assisted, green water/oil biphasic strategy for the in situ synthesis of CsPbBr3 nanocrystals encapsulated within mesoporous silica microspheres (CsPbBr3@MS). In this approach, ligand-free CsBr dissolved in water diffuses into the oil phase under ultrasonic agitation, where it reacts with oleic acid-coordinated Pb2+ species preloaded in the silica mesopores, resulting in confined nucleation and encapsulation of CsPbBr3 NCs within the silica framework. Optical characterization and stability assessments demonstrate that mesoporous encapsulation substantially enhances both the photoluminescence properties and environmental stability of CsPbBr3@MS. Furthermore, tuning the aqueous CsBr concentration enables optimization of the optical output, yielding a maximum photoluminescence quantum yield(PLQY) of up to 60%. A dense SiO2 shell was subsequently formed on the composite surface via TEOS, facilitated by trace water within the mesopores. This secondary passivation layer further improved optical durability, retaining 80% of the initial emission intensity after 60 h of water immersion. Overall, this work presents a green and effective strategy for synthesizing environmentally stable, high-performance perovskite nanomaterials.
Novel materials with polarized luminescence characteristics have the advantages of easy integration and low energy consumption in the field of display, and are expected to replace traditional polarizers to achieve miniaturization of devices. As a new type of luminescent material, lead-free metal halides have significant advantages such as low toxicity, adjustable band gap, high photoluminescence quantum yield (PLQY), and solution processing, thus showing important potential applications in the field of display. In this paper, (Ph4P)(2)SbCl5 nanocrystals/PVDF (polyvinylidene fluoride) composite fiber films with polarized luminescence properties were prepared in situ by electrospinning using antimony-based organic-inorganic hybrid lead-free metal halides as the material system. Transmission electron microscope(TEM) results showed that (Ph4P)(2)SbCl5 nanocrystals in the (Ph4P)(2)SbCl5/PVDF composite film exhibited nanorod morphology with a diameter of about 30 nm and distributed along the fiber axis. The (Ph4P)(2)SbCl5 nanocrystals/PVDF composite film exhibits uniform orange-red luminescence with an emission peak located at 600 nm, with a degree of polarization of 0. 5, and the PLQY reaches 58. 7%. The high polarized emission of the composite nanofiber film originates from the oriented transition dipole moment of the luminescent centers and the dielectric confinement effect of the PVDF matrix. Finally, a fluorescence-conversion-type orange-red LED device was fabricated using this composite nanofiber film as the fluorescence conversion layer and an ultraviolet light-emitting diode(UV LED) chip as the excitation source. The as-prepared (Ph4P)(2)SbCl5/PVDF polarized luminescence composite nanofiber film demonstrates promising potential for application in new display devices.
Quantum dot light-emitting diodes(QLEDs), owing to their high color purity, excellent emission efficiency, solution processability, full-color tunability, and compatibility with existing fabrication techniques, are regarded as strong candidates for next-generation high-resolution and low-power display devices. The realization of quantum dot patterning is a prerequisite for their display applications, giving rise to the emergence of various photolithographic techniques. At present, QLED patterning technologies are evolving from methods such as traditional photolithography and inkjet printing, which involve complex processes and often induce performance degradation, toward direct photolithography approaches that enable high resolution and nondestructive patterning. This article reviews the fundamental principles of direct photolithography of quantum dots, with a particular focus on the crosslinking mechanisms, lithographic performance, and impacts on QLED device characteristics of three representative photosensitive groups (azide, azo, and disulfide). Furthermore, the future development trends of direct photolithography for quantum dots and its potential directions in QLED displays are discussed, providing valuable insights for the advancement of patterned QLED display technologies.
Quantum dot light-emitting diodes(QLEDs) have attracted extensive attention in high-resolution displays and emerging fields such as augmented reality due to their narrow emission spectra, wide color gamut, high brightness, and low power consumption. However, the electroluminescent efficiency and stability of blue devices remain significantly inferior to those of red and green devices, and the lack of high-performance pure blue quantum dots(QDs) has limited the development of full-color displays. In this study, we report a synthesis strategy based on a ZnSe core with Cd ion-mediated emission tuning. CdZnSe core QDs were successfully prepared by rapid Cd2+ injection under high-temperature conditions to induce ion exchange, achieving an emission peak at 469 nm with a photoluminescence quantum yield(PLQY) of 79%. Subsequently, a multilayer shell structure of ZnSe/ZnSeS/ZnS was epitaxially grown on the core QDs, effectively passivating surface defects, enhancing structural stability, and significantly suppressing non-radiative recombination. The resulting multilayer-capped QDs exhibited a stable emission peak at 463 nm with a PLQY further increased to 92%, showing pure blue emission. QLED devices fabricated using these QDs demonstrated excellent electroluminescent performance, with a peak external quantum efficiency(EQE) of 18. 5% and a maximum brightness of 6. 34 & times;10(4) cd/m(2). In summary, this strategy, combining ion exchange with multilayer shell passivation, enables the fabrication of high-PLQY, stable pure blue QDs and high-performance QLED devices.
Quantum dot(QD) light-emitting diodes (QLEDs) are regarded as promising candidates for next-generation display and lighting technologies due to their excellent optoelectronic properties. However, the performance of blue QLEDs still lags far behind green and red counterparts, which seriously hinders the commercialization of QLED full-color displays. The main challenges arise from the deep valence band energy level of blue QDs, which leads to a large hole injection barrier at the QD/hole-transport layer (HTL) interface, as well as the insulating nature of long-chain oleic acid ligands that hinder charge transport. Moreover, the small energy offset between the core and shell materials in blue QDs facilitates carrier trapping at surface defect states, resulting in non-radiative recombination and thus reducing device efficiency. In this work, we introduce a multifunctional ligand, benzylhydroxylamine hydrochloride (BHACl), to modify the surface of blue QDs. The BHACl molecules replace the native long-chain oleic acid ligands, significantly improving the carrier transport within QD films. Meanwhile, the NH3+ groups effectively passivate surface sulfur dangling bonds, suppressing non-radiative recombination. In addition, the large dipole moment of BHACl upshifts the QD energy levels, thereby reducing the hole injection barrier. Benefiting from these synergistic effects, the fabricated blue QLEDs exhibit an external quantum efficiency (EQE) of 19. 2%, a peak luminance of 8 986 cd & centerdot;m(-2), and an operational lifetime of 18 170 h at an initial luminance of 100 cd & centerdot;m(-2), representing substantial improvements over the control devices.
Metal halide perovskite quantum dots(QDs)exhibit outstanding optoelectronic properties,including high photoluminescence quantum yields(PLQYs),high color purity,widely tunable bandgap,and solution-processability.They hold significant application potential in next-generation high-definition and flexible displays.After nearly a decade of rapid development,the device performance of perovskite QD light-emitting diodes(QLEDs)has significantly improved,with external quantum efficiencies(EQEs)exceeding 20%for red,green,and blue devices.Currently,the main challenges for perovskite QDs in display applications are poor material stability and the fabrication of high-resolution pixels.Photocrosslinking technology—which uses specific wavelength light sources(primarily UV)to trigger crosslinking reactions in molecules containing photosensitive groups,forming three-dimensional network structures to regulate material properties—holds promise for addressing perovskite QD stability issues while enabling high-resolution patterning of QDs.This paper systematically reviews recent research advances in photocrosslinking technology within perovskite systems,focusing on design strategies for enhancing the environmental stability of perovskite materials,achieving sub-micron pixel patterning,and optimizing the performance of patterned perovskite QLEDs.
Active-matrix organic light-emitting diode(AMOLED)display technology has become a mainstream solution in next-generation displays due to its high contrast ratio,rapid response,and flexibility.The pixel driving architecture critically determines display quality and energy efficiency.This paper systematically reviews the technical evolution of AMOLED pixel driving circuits:From the early simplified 2T1C architecture to the pipelined compensation architectures(e.g.,6T1C/7T1C)enabling real-time internal compensation of threshold voltage(Vth);Further advancing to LTPO wide-frequency driving architectures,which leverage hybrid low-temperature polycrystalline silicon and oxide(LTPS&Oxide)TFT backplane technology to support adaptive refresh rate adjustment(1～120 Hz),significantly reducing dynamic power consumption;And innovating with the One-Time Driving(OTD)architecture,which adopts nonvolatile memory and in-memory computing design.This approach decouples Vth latching from data refreshing,reducing the compensation frequency to 1/N of the data refresh rate(e.g.,N=20,compensating Vth once per 20 frames),thereby slashing dynamic power consumption by>50%at high refresh rates.The paper thoroughly analyzes circuit principles,timing diagram,and power models of these architectures.It highlights that the integration of high-mobility rare-earth-doped oxide TFTs(e.g.,Ln-IZO)with the OTD architecture will pave a new technical path for low-cost,low-power AMOLED displays.
In the field of aviation early warning,infrared weak target detection technology is crucial for long-range all-weather battlefield perception.Aiming at the problem of low probability of target detection and high false alarm rate caused by a small proportion of pixels and lack of features of infrared dim and small targets under complex background,a detection method for infrared dim and small targets under complex backgrounds via a spatio-temporal three-dimensional convolutional network was proposed.This method proposes a feature extraction backbone network that combines 2D convolution with 3D convolution,and combines spatial texture features and inter-frame motion features to achieve collaborative perception of target structure and temporal changes.According to the characteristics of infrared dim and small targets,a local contrast module is designed as a feature enhancement module to expand the receptive field for feature enhancement;In addition,introducing asymmetric attention mechanism for feature fusion increases the preservation of texture and positional information;Finally,the point regression loss function is used to calculate the detection results.In the experiment,the public data set was compared with the self-built data set,labeled and trained.Experimental results show that compared with the conventional multi-frame target detection network,the improved algorithm has a recall rate improvement of no less than 7.52%and an average precision improvement rate of no less than 6.46%.It can be effectively applied to infrared dim and small target detection in complex backgrounds,and embodies good robustness and adaptability.
As a core component of solar power generation systems,defects on the surface of photovoltaic panels can seriously affect their photovoltaic conversion efficiency and service life.In response to the challenges of identifying small defects and low contrast between defects and background in photovoltaic panel defect detection,this study proposes the SCA-YOLOv8n detection model.First,the SCConv cross-coupling module was designed to enhance the model's ability to extract multi-scale defect features while reducing redundant information through space-channel feature interactive reconstruction.Second,we construct the coordinate attention(CoordAtt)mechanism to focus on defect regions from the channel and spatial dimensions and suppress background interference.Finally,a lightweight adaptive downsampling(ADown)module is embedded to replace traditional stride convolution,reducing computational complexity while minimizing feature information loss.The experimental results show that the improved model achieves an mAP@0.5 of 94.4%,which is a 2.0%improvement over the original YOLOv8n model.Additionally,the number of parameters is reduced by 5.0%,and GFLOPs decrease by 4.9%.These results comprehensively demonstrate that the proposed improvements not only achieve model lightweighting but also significantly enhance the accuracy and reliability of photovoltaic panel defect detection.
To address the low detection accuracy of current traffic sign detection methods for small,blurred targets and complex environments,this paper proposes an improved traffic sign detection model YOLOv8-NTS,to enhance recognition performance in complex traffic scenarios.The model incorporates three key enhancements over YOLOv8:First,it introduces the lightweight Hybrid Attention Transformer(SlimHAT)module within the backbone network to strengthen global pixel information modeling and improve feature representation accuracy.Second,it replaces the original C2f module with the WT-C2fBlock module based on WTConv,reducing model parameters by 12.2%while maintaining detection accuracy.Finally,a novel detection head RFAhead was designed by integrating spatial attention mechanisms with convolutional operations,optimizing feature extraction and fusion processes to further enhance the model's object representation capability and robustness.Experiments on the TT100K traffic sign dataset demonstrate that compared to the baseline YOLOv8 model,the improved YOLOv8-NTS achieves significant performance gains:6.5%increase in precision,5.0%increase in recall,7.3%improvement in mAP50,and 5.3%enhancement in mAP50～90.The proposed YOLOv8-NTS model substantially improves traffic sign detection accuracy and generalization capabilities while maintaining low computational cost,validating the method's effectiveness and practical value.It provides reliable technical support for traffic sign recognition in intelligent transportation scenarios.
Conventional conjugated polymers face the critical challenge of achieving simultaneous optimization of electrical and mechanical properties.This study focuses on siloxane-side-chain-functionalized diketopyrrolopyrrole(DPP)-based conjugated polymer(DPP-4Si)blended with hydrogenated styrene-butadiene block copolymer(SEBS).Through precise control of film preparation and microphase separation structures,we developed high-performance elastic semiconductor films with a maximum mobility of 1.08 cm²·V-1·s-1.Fully stretchable transistors fabricated using the optimal blend ratio demonstrated remarkable electromechanical stability,maintaining over 72%current retention even under 100%tensile strain,showcasing exceptional stretchability.
Micro-LED displays achieve image rendering beyond the physical resolution of the display by means of sub-pixel multiplexing technology,which effectively reduces the production cost while improving the perceived resolution.However,the traditional unweighted average rendering algorithm for the triangular arrangement of RGB subpixels easily leads to the problem of color distortion,which in turn seriously affects the image display quality and user viewing experience.To solve this problem,this paper proposes an adaptive weighted subpixel rendering algorithm based on color difference.The algorithm consists of an image preprocessing module,a color space conversion module,an adaptive weight calculation module,and a subpixel rendering module.Firstly,the image preprocessing module extends the boundaries of the input image to ensure that no boundary-crossing problem occurs in the subsequent subpixel rendering process.Next,the color space conversion module separates and expands the channels of the read pixels and converts them from the sRGB color space to the CIELab color space.Subsequently,the adaptive weight calculation module achieves scene matching by calculating the color difference polarity between pixels and assigns values to the output subpixels.If it fails to match the corresponding scene,the center pixel is selected and the weight value is calculated based on the color difference of the neighboring pixels.Finally,the subpixel rendering module outputs the grayscale value of the subpixel based on the calculated weight value to complete the rendering of the final image.The experimental results show that compared with the traditional unweighted average subpixel rendering algorithm,the color difference-based adaptive weighted subpixel rendering algorithm proposed in this paper performs better on the DIV2K dataset.Specifically,the mean square error is reduced by 14.537 61,the peak signal-to-noise ratio is improved by 0.828 21 dB,and the structural similarity is improved by 0.014 96,the feature similarity index increased by 0.000 83,and the fidelity of visual information increased by 0.009 66.The algorithm significantly suppresses the color distortion problem,which effectively improves the display quality and the user viewing experience.
Single object tracking is a crucial task in computer vision,aiming to accurately locate a target in a video sequence.Although deep learning has significantly advanced the field of single object tracking,challenges such as target deformation,complex backgrounds,occlusion,and scale variation still remain.This paper systematically reviews the development of deep learning-based single object tracking methods over the past decade,covering traditional sequence models based on convolutional neural networks,recurrent neural networks,and Siamese networks,as well as hybrid architectures combining convolutional neural networks with Transformers and the latest approaches entirely based on Transformers.Furthermore,we evaluate the performance of different methods in terms of accuracy,robustness,and computational efficiency on benchmark datasets such as OTB100,LaSOT,and GOT-10k,followed by an in-depth analysis.Finally,we discuss the future research directions of deep learning-based single object tracking algorithms.
