Stimulated emission and lasing of GaN-based laser diodes(LDs)were reported at 1995[1]and 1996[2],right after the breakthrough of p-type doping[3−5],material quality[6]and the invention of high-brightness GaN-based LED...Stimulated emission and lasing of GaN-based laser diodes(LDs)were reported at 1995[1]and 1996[2],right after the breakthrough of p-type doping[3−5],material quality[6]and the invention of high-brightness GaN-based LEDs[7,8].However,it took much longer time for GaN-based LDs to achieve high power,high wall plug efficiency,and long lifetime.Until 2019,Nichia reported blue LDs with these performances[9],which open wide applications with GaN-based blue LDs.展开更多
Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yiel...Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.展开更多
Background Plant tissue culture has emerged as a tool for improving cotton propagation and genetics,but recalcitrance nature of cotton makes it difficult to develop in vitro regeneration.Cotton’s recalcitrance is inf...Background Plant tissue culture has emerged as a tool for improving cotton propagation and genetics,but recalcitrance nature of cotton makes it difficult to develop in vitro regeneration.Cotton’s recalcitrance is influenced by genotype,explant type,and environmental conditions.To overcome these issues,this study uses different machine learning-based predictive models by employing multiple input factors.Cotyledonary node explants of two commercial cotton cultivars(STN-468 and GSN-12)were isolated from 7–8 days old seedlings,preconditioned with 5,10,and 20 mg·L^(-1) kinetin(KIN)for 10 days.Thereafter,explants were postconditioned on full Murashige and Skoog(MS),1/2MS,1/4MS,and full MS+0.05 mg·L^(-1) KIN,cultured in growth room enlightened with red and blue light-emitting diodes(LED)combination.Statistical analysis(analysis of variance,regression analysis)was employed to assess the impact of different treatments on shoot regeneration,with artificial intelligence(AI)models used for confirming the findings.Results GSN-12 exhibited superior shoot regeneration potential compared with STN-468,with an average of 4.99 shoots per explant versus 3.97.Optimal results were achieved with 5 mg·L^(-1) KIN preconditioning,1/4MS postconditioning,and 80%red LED,with maximum of 7.75 shoot count for GSN-12 under these conditions;while STN-468 reached 6.00 shoots under the conditions of 10 mg·L^(-1) KIN preconditioning,MS with 0.05 mg·L^(-1) KIN(postconditioning)and 75.0%red LED.Rooting was successfully achieved with naphthalene acetic acid and activated charcoal.Additionally,three different powerful AI-based models,namely,extreme gradient boost(XGBoost),random forest(RF),and the artificial neural network-based multilayer perceptron(MLP)regression models validated the findings.Conclusion GSN-12 outperformed STN-468 with optimal results from 5 mg·L^(-1) KIN+1/4MS+80%red LED.Application of machine learning-based prediction models to optimize cotton tissue culture protocols for shoot regeneration is helpful to improve cotton regeneration efficiency.展开更多
The packaging quality of coaxial laser diodes(CLDs)plays a pivotal role in determining their optical performance and long-term reliability.As the core packaging process,high-precision laser welding requires precise co...The packaging quality of coaxial laser diodes(CLDs)plays a pivotal role in determining their optical performance and long-term reliability.As the core packaging process,high-precision laser welding requires precise control of process parameters to suppress optical power loss.However,the complex nonlinear relationship between welding parameters and optical power loss renders traditional trial-and-error methods inefficient and imprecise.To address this challenge,a physics-informed(PI)and data-driven collaboration approach for welding parameter optimization is proposed.First,thermal-fluid-solid coupling finite element method(FEM)was employed to quantify the sensitivity of welding parameters to physical characteristics,including residual stress.This analysis facilitated the identification of critical factors contributing to optical power loss.Subsequently,a Gaussian process regression(GPR)model incorporating finite element simulation prior knowledge was constructed based on the selected features.By introducing physics-informed kernel(PIK)functions,stress distribution patterns were embedded into the prediction model,achieving high-precision optical power loss prediction.Finally,a Bayesian optimization(BO)algorithm with an adaptive sampling strategy was implemented for efficient parameter space exploration.Experimental results demonstrate that the proposedmethod effectively establishes explicit physical correlations between welding parameters and optical power loss.The optimized welding parameters reduced optical power loss by 34.1%,providing theoretical guidance and technical support for reliable CLD packaging.展开更多
A binary-mixed electron transport layer(ETL)has been reported for constructing solution-processable near-infrared organic light-emitting diodes(NIR OLEDs).Relative to the single-component ETL,the binarymixed ETL compo...A binary-mixed electron transport layer(ETL)has been reported for constructing solution-processable near-infrared organic light-emitting diodes(NIR OLEDs).Relative to the single-component ETL,the binarymixed ETL composed of PDINN:TPBi can enhance the carrier transport capacity,reduce device impedance,and weaken fiuorescence quenching of the emitting layer.By carefully selecting an appropriate luminescent material Y5(a nonfullerene electron acceptor in organic solar cells)and precisely fine-tuning the molecular aggregation in active layer using a mixed solvent,the morphology is optimized and luminescence performance is enhanced,resulting in efficient NIR OLEDs with an emission peak at 890 nm.The experiment showcases a Y5-based near-infrared OLED with a maximum radiance of 34.9 W sr^(-1)m^(-2)and a maximum external quantum efficiency of 0.50%,which is among the highest values reported for nondoped fiuorescent NIR OLEDs with an emission peak over 850 nm.展开更多
GaN diodes for high energy(64.8 MeV)proton detection were fabricated and investigated.A comparison of the performance of GaN diodes with different structures is presented,with a focus on sapphire and on GaN substrates...GaN diodes for high energy(64.8 MeV)proton detection were fabricated and investigated.A comparison of the performance of GaN diodes with different structures is presented,with a focus on sapphire and on GaN substrates,Schottky and pin diodes,and different active layer thicknesses.Pin diodes fabricated on a sapphire substrate are the best choice for a GaN proton detector working at 0 V bias.They are sensitive(minimum detectable proton beam<1 pA/cm^(2)),linear as a function of proton current and fast(<1 s).High proton current sensitivity and high spatial resolution of GaN diodes can be exploited in the future for proton imaging of patients in proton therapy.展开更多
Perovskite light-emitting diodes(PeLEDs)have shown outstanding potential in next-generation lighting and display owing to the advantages of broad spectral tunability,excellent color purity,high photoluminescence quant...Perovskite light-emitting diodes(PeLEDs)have shown outstanding potential in next-generation lighting and display owing to the advantages of broad spectral tunability,excellent color purity,high photoluminescence quantum yields(PLQYs),and low processing cost.Device efficiency and stability are crucial indicators to evaluate whether a PeLED can meet commercial application requirements.In this review,we first discuss strategies for achieving high external quantum efficiencies(EQEs),including controlling charge injection and balance,enhancing radiative recombination,and improving light outcoupling efficiency.Next,we review recent advances in operational stability of PeLEDs and emphasize the mechanisms of degradation in PeLEDs,including ion migration,structural transformations,chemical interactions,and thermal degradation.Through detailed analysis and discussion,this review aims to facilitate progress and innovation in highly efficient and stable PeLEDs,which have significant promise for display and solid-state lighting technologies,as well as other emerging applications.展开更多
Triphenylamine(TPA)is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence(TADF)emitters owing to its suitable dihedral angle that could enhance radiative ...Triphenylamine(TPA)is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence(TADF)emitters owing to its suitable dihedral angle that could enhance radiative decay to compete with the serious non-radiative decay.However,the moderate electron-donating capacity of TPA seriously limits the selection of acceptor for constructing longwavelength TADF emitters with narrow bandgaps.To address this issue,in this work,the peripheral benzene of TPA was replaced with 1,4-benzodioxane and anisole to obtain two new electrondonating units N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N-phenyl-2,3-dihydrobenzo[b][1,4]dioxin-6-amine(TPADBO,−5.02 eV)and 4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline(TPAMO,−5.00 eV),which possess much shallower highest occupied molecule orbital(HOMO)energy levels than the prototype TPA(−5.33 eV).Based on TPA and the modified TPA donor fragments,three TADF emitters were designed and synthesized,namely Py-TPA,Py-TPADBO and Py-TPAMO,with the same acceptor fragment 12-(2,6-diisopropylphenyl)pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline(Py).Among them,Py-TPAMO exhibits the highest photoluminescence quantum yield of 78.4%and the smallest singlet-triplet energy gap,which is because the introduction of anisole does not cause significant molecule deformation for the excited Py-TPAMO.And Py-TPAMO-based OLEDs successfully realize a maximum external quantum efficiency of 25.5%with the emission peak at 605 nm.This work provides a series of candidate of donor fragments for the development of efficient long-wavelength TADF emitters.展开更多
Colloidal quantum dots(CQDs)are highly regarded for their outstanding photovoltaic characteristics,including excellent color purity,stability,high photoluminescence quantum yield(PLQY),narrow emission spectra,and ease...Colloidal quantum dots(CQDs)are highly regarded for their outstanding photovoltaic characteristics,including excellent color purity,stability,high photoluminescence quantum yield(PLQY),narrow emission spectra,and ease of solution processing.Despite significant progress in quantum dot light-emitting diodes(QLEDs)technology since its inception in 1994,blue QLEDs still fall short in efficiency and lifespan compared to red and green versions.The toxicity concerns associated with Cd/Pb-based quantum dots(QDs)have spurred the development of heavy-metal-free alternatives,such as groupⅡ−Ⅵ(e.g.,ZnSe-based QDs),groupⅢ−Ⅴ(e.g.,InP,GaN QDs),and carbon dots(CDs).In this review,we discuss the key properties and development history of quantum dots(QDs),various synthesis approaches,the role of surface ligands,and important considerations in developing core/shell(C/S)structured QDs.Additionally,we provide an outlook on the challenges and future directions for blue QLEDs.展开更多
The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investiga...The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices.展开更多
As an inherent current-driven device,the luminous intensity of a single-unit perovskite light-emitting diode is directly proportional to the current density.However,this relationship can lead to a deterioration in the...As an inherent current-driven device,the luminous intensity of a single-unit perovskite light-emitting diode is directly proportional to the current density.However,this relationship can lead to a deterioration in the operational lifetime of the device at high current densities.In contrast,a tandem device structure,not only requires less current to achieve equivalent brightness compared to a single-unit device but also nearly achieves the combined efficiencies of each light-emitting unit.Herein,we present recommendations and protocols designed to facilitate the fabrication of all-tandem perovskite light-emitting diode,with the aim of benefiting both the research and industrial communities.展开更多
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
Wearable electronics face a significant challenge related to the limited permeability of electronic materials/devices.This issue results in sweat accumulation across the interface of the device and skin following a sp...Wearable electronics face a significant challenge related to the limited permeability of electronic materials/devices.This issue results in sweat accumulation across the interface of the device and skin following a specific period of use[1−3].Not only does it bring about discomfort for users regarding thermos-physiology,but it also has a detrimental effect on interface adhesion and signal quality,thus hindering exact sig-nal monitoring during prolonged periods[4−6].展开更多
A nitrogen-polarity(N-polarity)GaN-based high electron mobility transistor(HEMT)shows great potential for high-fre-quency solid-state power amplifier applications because its two-dimensional electron gas(2DEG)density ...A nitrogen-polarity(N-polarity)GaN-based high electron mobility transistor(HEMT)shows great potential for high-fre-quency solid-state power amplifier applications because its two-dimensional electron gas(2DEG)density and mobility are mini-mally affected by device scaling.However,the Schottky barrier height(SBH)of N-polarity GaN is low.This leads to a large gate leakage in N-polarity GaN-based HEMTs.In this work,we investigate the effect of annealing on the electrical characteristics of N-polarity GaN-based Schottky barrier diodes(SBDs)with Ni/Au electrodes.Our results show that the annealing time and tem-perature have a large influence on the electrical properties of N-polarity GaN SBDs.Compared to the N-polarity SBD without annealing,the SBH and rectification ratio at±5 V of the SBD are increased from 0.51 eV and 30 to 0.77 eV and 7700,respec-tively,and the ideal factor of the SBD is decreased from 1.66 to 1.54 after an optimized annealing process.Our analysis results suggest that the improvement of the electrical properties of SBDs after annealing is mainly due to the reduction of the inter-face state density between Schottky contact metals and N-polarity GaN and the increase of barrier height for the electron emis-sion from the trap state at low reverse bias.展开更多
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
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
In the past few years,many groups have focused on the research and development of GaN-based ultraviolet laser diodes(UV LDs).Great progresses have been achieved even though many challenges exist.In this article,we ana...In the past few years,many groups have focused on the research and development of GaN-based ultraviolet laser diodes(UV LDs).Great progresses have been achieved even though many challenges exist.In this article,we analyze the challenges of developing GaN-based ultraviolet laser diodes,and the approaches to improve the performance of ultraviolet laser diode are reviewed.With these techniques,room temperature(RT)pulsed oscillation of AlGaN UVA(ultraviolet A)LD has been realized,with a lasing wavelength of 357.9 nm.Combining with the suppression of thermal effect,the high output power of 3.8 W UV LD with a lasing wavelength of 386.5 nm was also fabricated.展开更多
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
To improve the internal quantum efficiency(IQE)and light output power of In Ga N light-emitting diodes(LEDs),we proposed an In-composition gradient increase and decrease In Ga N quantum barrier structure.Through analy...To improve the internal quantum efficiency(IQE)and light output power of In Ga N light-emitting diodes(LEDs),we proposed an In-composition gradient increase and decrease In Ga N quantum barrier structure.Through analysis of its P-I graph,carrier concentration,and energy band diagram,the results showed that when the current was 100 m A,the In-composition gradient decrease quantum barrier(QB)structure could effectively suppress electron leakage while improving hole injection efficiency,resulting in an increase in carrier concentration in the active region and an improvement in the effective recombination rate in the quantum well(QW).As a result,the IQE and output power of the LED were effectively improved.展开更多
As one of the promising next-generation light conversion materials,indium phosphide quantum dots(InP QDs)deserve much attention due to their great optical performances and environmentally friendly properties in partic...As one of the promising next-generation light conversion materials,indium phosphide quantum dots(InP QDs)deserve much attention due to their great optical performances and environmentally friendly properties in particular.Herein,InP-based QDs are embedded into mesoporous SBA-15 and solid QDs/SBA-15 composites are prepared,which exhibit 1.5 times higher photoluminescence quantum yield(PLQY)and narrower full width of half maximum(FWHM)than traditional QDs powder thanks to the reduction of light reabsorption and the optical waveguide effect of mesoporous structure.These advantages contribute to the performance enhancement of light-emitting diodes(LEDs).The luminous efficacy of the LED with green QDs/SBA-15 is 99.49 lm/W,which is higher than that of QDs powder(66.14 lm/W).In addition,the white LED fabricated with green and red InP-based QDs/SBA-15 shows luminous efficacy of 61.38 lm/W.More importantly,the luminous efficacy of the white LED is improved to 129.62 lm/W when using the K_(2)SiF_(6):Mn^(4+)instead of red InP-based QDs/SBA-15,because the K_(2)SiF_(6):Mn^(4+)does not absorb the emission from green InP-based QDs/SBA-15.This value is higher than those white LEDs with InP-based QDs reported previously.It is believed that this study demonstrates the promising potential of InP-based QDs for optoelectronic applications.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province(Grant.BK20232042).
文摘Stimulated emission and lasing of GaN-based laser diodes(LDs)were reported at 1995[1]and 1996[2],right after the breakthrough of p-type doping[3−5],material quality[6]and the invention of high-brightness GaN-based LEDs[7,8].However,it took much longer time for GaN-based LDs to achieve high power,high wall plug efficiency,and long lifetime.Until 2019,Nichia reported blue LDs with these performances[9],which open wide applications with GaN-based blue LDs.
文摘Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.
文摘Background Plant tissue culture has emerged as a tool for improving cotton propagation and genetics,but recalcitrance nature of cotton makes it difficult to develop in vitro regeneration.Cotton’s recalcitrance is influenced by genotype,explant type,and environmental conditions.To overcome these issues,this study uses different machine learning-based predictive models by employing multiple input factors.Cotyledonary node explants of two commercial cotton cultivars(STN-468 and GSN-12)were isolated from 7–8 days old seedlings,preconditioned with 5,10,and 20 mg·L^(-1) kinetin(KIN)for 10 days.Thereafter,explants were postconditioned on full Murashige and Skoog(MS),1/2MS,1/4MS,and full MS+0.05 mg·L^(-1) KIN,cultured in growth room enlightened with red and blue light-emitting diodes(LED)combination.Statistical analysis(analysis of variance,regression analysis)was employed to assess the impact of different treatments on shoot regeneration,with artificial intelligence(AI)models used for confirming the findings.Results GSN-12 exhibited superior shoot regeneration potential compared with STN-468,with an average of 4.99 shoots per explant versus 3.97.Optimal results were achieved with 5 mg·L^(-1) KIN preconditioning,1/4MS postconditioning,and 80%red LED,with maximum of 7.75 shoot count for GSN-12 under these conditions;while STN-468 reached 6.00 shoots under the conditions of 10 mg·L^(-1) KIN preconditioning,MS with 0.05 mg·L^(-1) KIN(postconditioning)and 75.0%red LED.Rooting was successfully achieved with naphthalene acetic acid and activated charcoal.Additionally,three different powerful AI-based models,namely,extreme gradient boost(XGBoost),random forest(RF),and the artificial neural network-based multilayer perceptron(MLP)regression models validated the findings.Conclusion GSN-12 outperformed STN-468 with optimal results from 5 mg·L^(-1) KIN+1/4MS+80%red LED.Application of machine learning-based prediction models to optimize cotton tissue culture protocols for shoot regeneration is helpful to improve cotton regeneration efficiency.
基金funded by the National Key R&D Program of China,Grant No.2024YFF0504904.
文摘The packaging quality of coaxial laser diodes(CLDs)plays a pivotal role in determining their optical performance and long-term reliability.As the core packaging process,high-precision laser welding requires precise control of process parameters to suppress optical power loss.However,the complex nonlinear relationship between welding parameters and optical power loss renders traditional trial-and-error methods inefficient and imprecise.To address this challenge,a physics-informed(PI)and data-driven collaboration approach for welding parameter optimization is proposed.First,thermal-fluid-solid coupling finite element method(FEM)was employed to quantify the sensitivity of welding parameters to physical characteristics,including residual stress.This analysis facilitated the identification of critical factors contributing to optical power loss.Subsequently,a Gaussian process regression(GPR)model incorporating finite element simulation prior knowledge was constructed based on the selected features.By introducing physics-informed kernel(PIK)functions,stress distribution patterns were embedded into the prediction model,achieving high-precision optical power loss prediction.Finally,a Bayesian optimization(BO)algorithm with an adaptive sampling strategy was implemented for efficient parameter space exploration.Experimental results demonstrate that the proposedmethod effectively establishes explicit physical correlations between welding parameters and optical power loss.The optimized welding parameters reduced optical power loss by 34.1%,providing theoretical guidance and technical support for reliable CLD packaging.
基金supported by the National Natural Science Foundation of China(No.51973020)Beijing Natural Science Foundation(No.2232052)。
文摘A binary-mixed electron transport layer(ETL)has been reported for constructing solution-processable near-infrared organic light-emitting diodes(NIR OLEDs).Relative to the single-component ETL,the binarymixed ETL composed of PDINN:TPBi can enhance the carrier transport capacity,reduce device impedance,and weaken fiuorescence quenching of the emitting layer.By carefully selecting an appropriate luminescent material Y5(a nonfullerene electron acceptor in organic solar cells)and precisely fine-tuning the molecular aggregation in active layer using a mixed solvent,the morphology is optimized and luminescence performance is enhanced,resulting in efficient NIR OLEDs with an emission peak at 890 nm.The experiment showcases a Y5-based near-infrared OLED with a maximum radiance of 34.9 W sr^(-1)m^(-2)and a maximum external quantum efficiency of 0.50%,which is among the highest values reported for nondoped fiuorescent NIR OLEDs with an emission peak over 850 nm.
基金support from MATRIX(ANR-22-CE92-0047)with financial support from ITMI Cancer of Aviesan within the framework of the 2021−2030 Cancer Control Strategy,on funds administrated by INSERM through the project NECTAR.Matilde Siviero acknowledges funding from the French−German University/Saarbrücken(contract CDOC-06-2022).
文摘GaN diodes for high energy(64.8 MeV)proton detection were fabricated and investigated.A comparison of the performance of GaN diodes with different structures is presented,with a focus on sapphire and on GaN substrates,Schottky and pin diodes,and different active layer thicknesses.Pin diodes fabricated on a sapphire substrate are the best choice for a GaN proton detector working at 0 V bias.They are sensitive(minimum detectable proton beam<1 pA/cm^(2)),linear as a function of proton current and fast(<1 s).High proton current sensitivity and high spatial resolution of GaN diodes can be exploited in the future for proton imaging of patients in proton therapy.
基金supported by the National Key Research and Development Program of China(No.2022YFA1204800)the Scientific Research Innovation Capability Support Project for Young Faculty(No.ZYGXQNJSKYCXNLZCXM-I25),China+1 种基金the National Natural Science Foundation of China(No.62274144)the Zhejiang Provincial Government,China.
文摘Perovskite light-emitting diodes(PeLEDs)have shown outstanding potential in next-generation lighting and display owing to the advantages of broad spectral tunability,excellent color purity,high photoluminescence quantum yields(PLQYs),and low processing cost.Device efficiency and stability are crucial indicators to evaluate whether a PeLED can meet commercial application requirements.In this review,we first discuss strategies for achieving high external quantum efficiencies(EQEs),including controlling charge injection and balance,enhancing radiative recombination,and improving light outcoupling efficiency.Next,we review recent advances in operational stability of PeLEDs and emphasize the mechanisms of degradation in PeLEDs,including ion migration,structural transformations,chemical interactions,and thermal degradation.Through detailed analysis and discussion,this review aims to facilitate progress and innovation in highly efficient and stable PeLEDs,which have significant promise for display and solid-state lighting technologies,as well as other emerging applications.
基金supported by the National Natural Science Foundation of China (Nos. 62222503, 52073040 and 52130304)the Sichuan Science and Technology Program (Nos. 2024NSFSC0012,2023NSFSC1973 and 2024NSFSC1446)+2 种基金the China Postdoctoral Science Foundation (Nos. 2023M740504 and GZC20230380)the Sichuan Provincial Human Resources and Social Security Department Programthe Collaborative Innovation Center of Suzhou Nano Science&Technology
文摘Triphenylamine(TPA)is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence(TADF)emitters owing to its suitable dihedral angle that could enhance radiative decay to compete with the serious non-radiative decay.However,the moderate electron-donating capacity of TPA seriously limits the selection of acceptor for constructing longwavelength TADF emitters with narrow bandgaps.To address this issue,in this work,the peripheral benzene of TPA was replaced with 1,4-benzodioxane and anisole to obtain two new electrondonating units N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N-phenyl-2,3-dihydrobenzo[b][1,4]dioxin-6-amine(TPADBO,−5.02 eV)and 4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline(TPAMO,−5.00 eV),which possess much shallower highest occupied molecule orbital(HOMO)energy levels than the prototype TPA(−5.33 eV).Based on TPA and the modified TPA donor fragments,three TADF emitters were designed and synthesized,namely Py-TPA,Py-TPADBO and Py-TPAMO,with the same acceptor fragment 12-(2,6-diisopropylphenyl)pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline(Py).Among them,Py-TPAMO exhibits the highest photoluminescence quantum yield of 78.4%and the smallest singlet-triplet energy gap,which is because the introduction of anisole does not cause significant molecule deformation for the excited Py-TPAMO.And Py-TPAMO-based OLEDs successfully realize a maximum external quantum efficiency of 25.5%with the emission peak at 605 nm.This work provides a series of candidate of donor fragments for the development of efficient long-wavelength TADF emitters.
基金supported by the National Key Research and Development Program of China(2024YFE0103600)the National Natural Science Foundation of China(NSFC)(62474119,62205230,and 62175171)Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices.
文摘Colloidal quantum dots(CQDs)are highly regarded for their outstanding photovoltaic characteristics,including excellent color purity,stability,high photoluminescence quantum yield(PLQY),narrow emission spectra,and ease of solution processing.Despite significant progress in quantum dot light-emitting diodes(QLEDs)technology since its inception in 1994,blue QLEDs still fall short in efficiency and lifespan compared to red and green versions.The toxicity concerns associated with Cd/Pb-based quantum dots(QDs)have spurred the development of heavy-metal-free alternatives,such as groupⅡ−Ⅵ(e.g.,ZnSe-based QDs),groupⅢ−Ⅴ(e.g.,InP,GaN QDs),and carbon dots(CDs).In this review,we discuss the key properties and development history of quantum dots(QDs),various synthesis approaches,the role of surface ligands,and important considerations in developing core/shell(C/S)structured QDs.Additionally,we provide an outlook on the challenges and future directions for blue QLEDs.
基金support from the National Key Research and Development Program of China(2024YFA1207700)National Natural Science Foundation of China(52072141,52102170).
文摘The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices.
基金support by the National Key Research and Development Program of China(No.2022YFA1204800)the National Natural Science Foundation of China(No.U21A2078)the Scientific Research Funds of Huaqiao University(No.23BS109).
文摘As an inherent current-driven device,the luminous intensity of a single-unit perovskite light-emitting diode is directly proportional to the current density.However,this relationship can lead to a deterioration in the operational lifetime of the device at high current densities.In contrast,a tandem device structure,not only requires less current to achieve equivalent brightness compared to a single-unit device but also nearly achieves the combined efficiencies of each light-emitting unit.Herein,we present recommendations and protocols designed to facilitate the fabrication of all-tandem perovskite light-emitting diode,with the aim of benefiting both the research and industrial communities.
基金supported by the Science and Technology Program of Shenzhen(Grant Nos.SGDX20201103095607022 and JCYJ20210324095003011)supported by the Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province.
文摘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.
文摘Wearable electronics face a significant challenge related to the limited permeability of electronic materials/devices.This issue results in sweat accumulation across the interface of the device and skin following a specific period of use[1−3].Not only does it bring about discomfort for users regarding thermos-physiology,but it also has a detrimental effect on interface adhesion and signal quality,thus hindering exact sig-nal monitoring during prolonged periods[4−6].
基金This work was supported by the National Key R&D Program of China(Nos.2022YFB3605205,2021YFB3601000,and 2021YFB3601002)the National Natural Science Foundation of China(Nos.U22A20134,62074069,62104078,and 62104079)the Science and Technology Developing Project of Jilin Province(Nos.20220201065GX,20230101053JC,and 20220101119JC).
文摘A nitrogen-polarity(N-polarity)GaN-based high electron mobility transistor(HEMT)shows great potential for high-fre-quency solid-state power amplifier applications because its two-dimensional electron gas(2DEG)density and mobility are mini-mally affected by device scaling.However,the Schottky barrier height(SBH)of N-polarity GaN is low.This leads to a large gate leakage in N-polarity GaN-based HEMTs.In this work,we investigate the effect of annealing on the electrical characteristics of N-polarity GaN-based Schottky barrier diodes(SBDs)with Ni/Au electrodes.Our results show that the annealing time and tem-perature have a large influence on the electrical properties of N-polarity GaN SBDs.Compared to the N-polarity SBD without annealing,the SBH and rectification ratio at±5 V of the SBD are increased from 0.51 eV and 30 to 0.77 eV and 7700,respec-tively,and the ideal factor of the SBD is decreased from 1.66 to 1.54 after an optimized annealing process.Our analysis results suggest that the improvement of the electrical properties of SBDs after annealing is mainly due to the reduction of the inter-face state density between Schottky contact metals and N-polarity GaN and the increase of barrier height for the electron emis-sion from the trap state at low reverse bias.
基金supported by the Science and Technology Development Fund,Macao SAR(File no.FDCT-0082/2021/A2,0010/2022/AMJ,006/2022/ALC)UM's research fund(File no.MYRG2022-00241-IAPME,MYRGCRG2022-00009-FHS)+2 种基金the research fund from Wuyi University(EF38/IAPME-XGC/2022/WYU)the Natural Science Foundation of China(61935017,62175268)Science,Technology and Innovation Commission of Shenzhen Municipality(Project Nos.JCYJ20220530113015035,JCYJ20210324120204011,and KQTD2015071710313656).
文摘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.
基金This work was financially supported by the National Key Research and Development Program of China(2022YFB3602902)the Key Projects of National Natural Science Foundation of China(62234004)+5 种基金Innovation and Entrepreneurship Team of Zhejiang Province(2021R01003)Science and Technology Innovation 2025 Major Project of Ningbo(2022Z085)Ningbo 3315 Programme(2020A-01-B)YONGJIANG Talent Introduction Programme(2021A-038-B)Flexible Electronics Zhejiang Province Key Laboratory Fund Project(2022FEO02)Zhejiang Provincial Natural Science Foundation of China(LR21F050001).
文摘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.
基金This work was supported by the National Key R&D Program of China(2022YFB3605104)National Natural Science Foundation of China(62250038,61904172,61974162,62034008,62074142,and 62074140)+1 种基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB43030101)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2022SX-TD016).
文摘In the past few years,many groups have focused on the research and development of GaN-based ultraviolet laser diodes(UV LDs).Great progresses have been achieved even though many challenges exist.In this article,we analyze the challenges of developing GaN-based ultraviolet laser diodes,and the approaches to improve the performance of ultraviolet laser diode are reviewed.With these techniques,room temperature(RT)pulsed oscillation of AlGaN UVA(ultraviolet A)LD has been realized,with a lasing wavelength of 357.9 nm.Combining with the suppression of thermal effect,the high output power of 3.8 W UV LD with a lasing wavelength of 386.5 nm was also fabricated.
基金funded by the China Agriculture Research System(CARS-15-16).
文摘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.
基金supported by the National Natural Science Foundation of China(No.62174148)the National Key Research and Development Program(Nos.2022YFE0112000 and 2016YFE0118400)+2 种基金the Key Program for International Joint Research of Henan Province(No.231111520300)the Ningbo Major Project of‘Science,Technology and Innovation 2025’(No.2019B10129)the Zhengzhou 1125 Innovation Project(No.ZZ2018-45)。
文摘To improve the internal quantum efficiency(IQE)and light output power of In Ga N light-emitting diodes(LEDs),we proposed an In-composition gradient increase and decrease In Ga N quantum barrier structure.Through analysis of its P-I graph,carrier concentration,and energy band diagram,the results showed that when the current was 100 m A,the In-composition gradient decrease quantum barrier(QB)structure could effectively suppress electron leakage while improving hole injection efficiency,resulting in an increase in carrier concentration in the active region and an improvement in the effective recombination rate in the quantum well(QW).As a result,the IQE and output power of the LED were effectively improved.
基金supported by the National Natural Science Foundation of China(Nos.62074044 and 62004231)the Zhongshan-Fudan Joint Innovation Center,and Jihua Laboratory Projects of Guangdong Province(No.X190111UZ190).
文摘As one of the promising next-generation light conversion materials,indium phosphide quantum dots(InP QDs)deserve much attention due to their great optical performances and environmentally friendly properties in particular.Herein,InP-based QDs are embedded into mesoporous SBA-15 and solid QDs/SBA-15 composites are prepared,which exhibit 1.5 times higher photoluminescence quantum yield(PLQY)and narrower full width of half maximum(FWHM)than traditional QDs powder thanks to the reduction of light reabsorption and the optical waveguide effect of mesoporous structure.These advantages contribute to the performance enhancement of light-emitting diodes(LEDs).The luminous efficacy of the LED with green QDs/SBA-15 is 99.49 lm/W,which is higher than that of QDs powder(66.14 lm/W).In addition,the white LED fabricated with green and red InP-based QDs/SBA-15 shows luminous efficacy of 61.38 lm/W.More importantly,the luminous efficacy of the white LED is improved to 129.62 lm/W when using the K_(2)SiF_(6):Mn^(4+)instead of red InP-based QDs/SBA-15,because the K_(2)SiF_(6):Mn^(4+)does not absorb the emission from green InP-based QDs/SBA-15.This value is higher than those white LEDs with InP-based QDs reported previously.It is believed that this study demonstrates the promising potential of InP-based QDs for optoelectronic applications.
