The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon ...The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.展开更多
As an important index to measure the degree of entanglement in quantum systems,concurrence plays an important role in practical research.In this paper,we study the concurrence between two qubits in triangular triple q...As an important index to measure the degree of entanglement in quantum systems,concurrence plays an important role in practical research.In this paper,we study the concurrence between two qubits in triangular triple quantum dot structure.Through calculation and simulation,it is found that concurrence is mainly affected by the interdot coupling strength t,Coulomb interactionU,temperature T,and electrode coupling G.Through comparative studies with parallel triple quantum dot structures,we demonstrate that the triangular geometry exhibits significantly enhanced concurrence under identical conditions.In addition,under the condition that concurrence exceeds 0.9,the functional relationship between t and U is obtained through simulation,which provides theoretical support for quantum dot regulation under high entanglement.Finally,we demonstrate the feasibility of implementing a three-qubit quantum gate,using the Toffoli gate as a representative example,under the condition that the triangular triple quantum dot system maintains high entanglement.展开更多
Flexible materials with perovskite quantum dots(PQDs)are widely used in the field of photonics and opto-electronics due to their unique properties.Development of new materials based on these nanoparticles,incorporated...Flexible materials with perovskite quantum dots(PQDs)are widely used in the field of photonics and opto-electronics due to their unique properties.Development of new materials based on these nanoparticles,incorporated into flexible and lightweight nonwoven fabrics,demonstrated high photoconductivity and efficient light energy conversion.In this work,we propose a method for creating a stable luminescent nonwoven material using electrospinning,in which inorganic salt precursors are used without the need for additional stabilizers.Equimolar solutions of cesium and lead(Ⅱ)bromide were mixed with a fluoroplast,resulting in a series of samples.Luminescent materials were obtained containing PQDs with a composition of CsPbBr_(3),with emission peaks ranging from 507 to 517 nm under 365-nm excitation.We have experimentally established and theoretically confirmed that the peak position is related to the size of the particles formed in the fiber during electrospinning and depends on processing time.Developed materials exhibited stable luminescent properties for up to 2.5 years,making them a promising candidate for the development of new flexible optoelectronic devices based on PQDs.展开更多
Quantum dot systems emerge as promising platforms for studying nanoscale thermoelectric effects and quantum fluctuation phenomena.In this work,we investigate the thermodynamic performance of a Coulomb-blockaded quantu...Quantum dot systems emerge as promising platforms for studying nanoscale thermoelectric effects and quantum fluctuation phenomena.In this work,we investigate the thermodynamic performance of a Coulomb-blockaded quantum dot operating as a quantum heat engine using the quantum master equation approach.By incorporating full counting statistics,we analyze both average transport properties and current fluctuations in this nanoscale system.We demonstrate that electron-electron interactions significantly enhance thermoelectric performance by increasing both the output power and energy conversion efficiency.Furthermore,we show that Coulomb interactions suppress current fluctuations while preserving the validity of the thermodynamic uncertainty relation.Our results provide important insights into the interplay between quantum effects and thermodynamic principles in nanoscale heat engines.展开更多
Corn stover,an agricultural waste,was used to prepare nitrogen self-doped carbon quantum dots(CQDs)through a simple hydrothermal method with only water at near room temperature for the first time.The surface,electroch...Corn stover,an agricultural waste,was used to prepare nitrogen self-doped carbon quantum dots(CQDs)through a simple hydrothermal method with only water at near room temperature for the first time.The surface,electrochemical,and photovoltaic characteristics of CQDs doped TiO_(2)in dye-sensitized solar cells(DSSCs)were thoroughly and systematically examined.The average diameter of blue-fluorescence CQDs measured by a high-resolution transmission electron microscope(HR-TEM)was 4.63±0.87 nm,which consisted of polar functional groups.The highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)energy of the biomass-derived CQDs,determined by the cyclic voltammetry(CV)test,were,−5.48 eV and−3.89 eV,respectively.The negative shift of flat band potential(Vfb)in CQDs incorporated photoanode implies the fermi level shifted upward.Experimental results revealed that the improved performance of DSSCs was due to charge transport enhancement and separation,which resulted in the improved energy level configuration between TiO_(2),CQDs,and electrolytes.In this regard,the CQDs serve as a mediator that enables charge carrier transport without hindrance.In this study,CQDs added to TiO_(2)+N719,increased short circuit current density(JSC)and power conversion efficiency(PCE)value by∼26.00%(10.13 to 12.69 mA/cm^(2))and 27.20%(4.78%to 6.08%),respectively.展开更多
The endocrine-disrupting chemicals(EDCs)and antibiotics are causing negative effects on human beings and animals by disrupting the endocrine system and spreading antimicrobial resistance.The current need is to eradica...The endocrine-disrupting chemicals(EDCs)and antibiotics are causing negative effects on human beings and animals by disrupting the endocrine system and spreading antimicrobial resistance.The current need is to eradicate pharmaceutical waste from water bodies using advanced catalytic systems with high efficiency.Novel ternary carbon quantum dots(CQDs)decorated Z-Scheme WS_(2)-PANI nanocomposite was prepared by a green synthesis assisted in-situ polymerization for the photodegradation and detection of Estradiol(EST)and Nitrofurantoin(NFT).HRTEM micrographs revealed the formation of CQDs with a mean size of 4nm anchored on the surface of WS_(2)/PANI(width:PANI~20-30nm).The ternary nanocomposite showed excellent photocatalytic activity,degraded NFT(95.7%in 60min),and EST(96.6%in 60min).The rate kinetics study confirms the reaction followed pseudo first-order model.This heterostructure exhibited enhanced performances by modulating the energy level configuration,enhancing the absorption of visible light(2.4eV),and significantly improving the charge separation,three times higher than pristine WS_(2).These are highly favorable for increasing the generation of photoinduced charges and enhancing the overall performance of the catalyst.Further,the electrochemical sensor was prepared using CQDs@WS_(2)/PANI nanocomposite on a paper-based electrode.The CQDs@WS_(2)/PANI exhibit a linear response of 0.1-100nM,with a limit of detection of 13nM.This synergistic interfacial interaction resulted in the significantly improved electrochemical performance of the modified electrode.The proposed Z-scheme was justified by electron paramagnetic resonance(EPR)and scavenger experiment.An intermediate degradation pathway was also proposed.The synthesized materials were characterized using FESEM,HRTEM,XRD,FTIR,XPS,UV-visible spectroscopy,PL,and TRPL.Therefore,this study provides a direct approach to fabricate a heterojunction that combines two-dimensional,one dimensional,and zero-dimensional properties,enabling control over the energy level configuration and subsequent improvements in photocatalytic and electrocatalytic efficiency.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
Aqueous zinc ion batteries have received widespread attention.However,the growth of zinc dendrites and hydrogen evolution reaction generation seriously hinder the practical application of zinc ion bat-teries.Herein,it...Aqueous zinc ion batteries have received widespread attention.However,the growth of zinc dendrites and hydrogen evolution reaction generation seriously hinder the practical application of zinc ion bat-teries.Herein,it is reported that a multifunctional dendrites-free low-temperature PVA-based gel elec-trolyte by introducing negatively charged polymer carbon quantum dots(QDs)and the organic antifreeze dimethyl sulfoxide(DMSO)into it.The QDs carrying a large number of functional groups on the surface can effectively adsorb Zn^(2+),eliminating the“tip effect”,and inducing the uniform deposition of Zn^(2+)and the formation of a dendrites-free structure.Meanwhile,the solvation structure of adsorbed Zn^(2+)can be controlled by charged groups to reduce the generation of side reactions,thus obtaining high-performance zinc ion batteries.The Zn/polyaniline(PANi)full battery can be stably cycled more than 1000 times at-20℃,and the design of this gel electrolyte can provide good feasibility for safe,stable,and flexible energy storage devices.展开更多
The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS...The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.展开更多
Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is a highly successful conductive polymer utilized as an electrode material in energy storage units for portable and wearable electronic de-vices.Neve...Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is a highly successful conductive polymer utilized as an electrode material in energy storage units for portable and wearable electronic de-vices.Nevertheless,employing PEDOT:PSS in supercapacitors(SC)in its pristine state presents challenges due to its suboptimal electrochemical performance and operational instability.To surmount these limita-tions,PEDOT:PSS has been integrated with carbon-based materials to form flexible electrodes,which ex-hibit physical and chemical stability during SC operation.We developed a streamlined fabrication process for high-performance SC electrodes composed of PEDOT:PSS and carbon quantum dots(CQDs).The CQDs were synthesized under microwave irradiation,yielding green-and red-light emissions.Through optimiz-ing the ratios of CQDs to PEDOT:PSS,the SC electrodes were prepared using a spray-coating technique,marking a significant improvement in device performance with a high volumetric capacitance(104.10 F cm-3),impressive energy density(19.68 Wh cm^(-3)),and excellent cyclic stability,retaining~85% of its original volumetric capacitance after 15,000 repeated GCD cycles.Moreover,the SCs,when utilized as a flexible substrate,demonstrated the ability to maintain up to~85% of their electrochemical performance even after 3,000 bending cycles(at a bending angle of 60°).These attributes render this hybrid composite an ideal candidate for a lightweight smart energy storage component in portable and wearable electronic technologies.展开更多
Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was...Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was prepared by powder metallurgy method.The composite powder was prepared by molecular blending method and ball milling method at first,and then densified into bulk material by spark plasma sintering(SPS).X-ray diffraction,Raman spectroscopy,infrared spectroscopy,and nuclear magnetic resonance were employed to characterize the CQD synthesized under different temperature conditions,and then CQDs with a higher degree of sp^(2)were utilized as the reinforcement to prepare composite materials with different contents.Mechanical properties and electrical conductivity results show that the tensile strength of the 0.2 CQD/Cu composite material is~31%higher than that of the pure copper sample,and the conductivity of 0.4 CQD/Cu is~96%IACS,which is as high as pure copper.TEM and HRTEM results show that good interface bonding of CQD and copper grain is the key to maintaining high mechanical and electrical conductivity.This research provides an important foundation and direction for new carbon materials reinforced metal matrix composites.展开更多
Carbon quantum dots are a new type of fluorescent nanomaterials with broad applications in drug delivery,bioimaging,solar cells,and photocatalysis due to their unique biocompatibility,optical properties and easy funct...Carbon quantum dots are a new type of fluorescent nanomaterials with broad applications in drug delivery,bioimaging,solar cells,and photocatalysis due to their unique biocompatibility,optical properties and easy functionalization.In the meantime,because of its high carbon content,renewable nature,and environmental friendliness,lignin has drawn the attention of researchers as a desirable raw material for creating carbon quantum dots.Here we review the synthesis of carbon quantum dots from lignin,focusing on synthetic methods,properties,and applications in energy,and photocatalysis.Later,we propose some new development prospects from preparation methods,luminescence mechanism research,application,and commercial cost of lignin carbon quantum dots.Finally,based on this,the development prospects of this field are prospected and summarized.展开更多
The preparation of red,green,and blue quantum dot(QD)pixelated arrays with high precision,resolution,and brightness poses a significant challenge on the development of advanced micro-displays for virtual,augmented,and...The preparation of red,green,and blue quantum dot(QD)pixelated arrays with high precision,resolution,and brightness poses a significant challenge on the development of advanced micro-displays for virtual,augmented,and mixed reality applications.Alongside the controlled synthesis of high-performance QDs,a reliable QD patterning technology is crucial in overcoming this challenge.Among the various methods available,photolithography-based patterning technologies show great potentials in producing ultra-fine QD patterns at micron scale.This review article presents the recent advancements in the field of QD patterning using photolithography techniques and explores their applications in micro-display technology.Firstly,we discuss QD patterning through photolithography techniques employing photoresist(PR),which falls into two categories:PRassisted photolithography and photolithography of QDPR.Subsequently,direct photolithography techniques based on photo-induced crosslinking of photosensitive groups and photo-induced ligand cleavage mechanisms are thoroughly reviewed.Meanwhile,we assess the performance of QD arrays fabricated using these photolithography techniques and their integration into QD light emitting diode display devices as well as color conversionbased micro light emitting diode display devices.Lastly,we summarize the most recent developments in this field and outline future prospects.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
Quantum dots(QDs),a type of nanoscale semiconductor material with unique optical and electrical properties like adjustable emission and high photoluminescence quantum yields,are suitable for applications in optoelectr...Quantum dots(QDs),a type of nanoscale semiconductor material with unique optical and electrical properties like adjustable emission and high photoluminescence quantum yields,are suitable for applications in optoelectronics.However,QDs are typically degraded under humid and high-temperature circumstances,greatly limiting their practical value.Coating the QD surface with an inorganic silica layer is a feasible method for improving stability and endurance in a variety of applications.This paper comprehensively reviews silica coating methodologies on QD surfaces and explores their applications in optoelectronic domains.Firstly,the paper provides mainstream silica coating approaches,which can be divided into two categories:in-situ hydrolysis of silylating reagents on QD surfaces and template techniques for encapsulation QDs.Subsequently,the recent applications of the silica-coated QDs on optoelectronic fields including light-emitting diodes,solar cells,photodetectors were discussed.Finally,it reviews recent advances in silica-coated QD technology and prospects for future applications.展开更多
With the rapid development of electric vehicles,hybrid electric vehicles and smart grids,people's demand for large-scale energy storage devices is increasingly intense.As a new type of secondary battery,potassium ...With the rapid development of electric vehicles,hybrid electric vehicles and smart grids,people's demand for large-scale energy storage devices is increasingly intense.As a new type of secondary battery,potassium ion battery is promising to replace the lithium-ion battery in the field of large-scale energy storage by virtue of its low price and environmental friendliness.At present,the research on the anode materials of potassium ion batteries mainly focuses on carbon materials and the design of various nanostructured metal-based materials.Problems such as poor rate performance and inferior cycle life caused by electrode structure comminution during charge and discharge have not been solved.Quantum dots/nanodots materials are a new type of nanomaterials that can effectively improve the utilization of electrode materials and reduce production costs.In addition,quantum dots/nanodots materials can enhance the electrode reaction kinetics,reduce the stress generated in cycling,and effectively alleviate the agglomeration and crushing of electrode materials.In this review,we will systematically introduce the synthesis methods,K+storage properties and K+storage mechanisms of carbon quantum dots and carbon-based transition metal compound quantum dots composites.This review will have significant references for potassium ion battery researchers.展开更多
Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-po...Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.展开更多
Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachm...Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachment and complex fabrication process introduce surface defects,compromising device stability and efficiency.In this work,we propose a solution-phase ligand exchange(SPLE)method utilizing inorganic ligands to develop stable p-type lead sulfide(PbS)CQD inks for the first time.Various amounts of tin(Ⅱ)iodide(SnI_(2))were mixed with lead halide(PbX_(2);X=I,Br)in the ligand solution.By precisely controlling the SnI_(2)concentration,we regulate the transition of PbS QDs from n-type to p-type.PbS CQDSCs were fabricated using two different HTL approaches:one with 1,2-ethanedithiol(EDT)-passivated QDs via the LbL method(control)and another with inorganic ligand-passivated QD ink(target).The target devices achieved a higher power conversion efficiency(PCE)of 10.93%,compared to 9.83%for the control devices.This improvement is attributed to reduced interfacial defects and enhanced carrier mobility.The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands,paving the way for high-performance and flexible CQD-based optoelectronic devices.展开更多
In this study,a carbon quantum dots modified maghemite catalyst(CQDs@γ-Fe_(2)O_(3))has been synthesized by a one-step solvothermal method for efficient persulfate(PDS)activation under visible light irradiation.Transm...In this study,a carbon quantum dots modified maghemite catalyst(CQDs@γ-Fe_(2)O_(3))has been synthesized by a one-step solvothermal method for efficient persulfate(PDS)activation under visible light irradiation.Transmission electron microscopy(TEM),scanning electron microscopy(SEM)and UV-vis diffuse reflectance spectroscopy(UV-vis DRS)characterization indicated that the formation of heterojunction structure between CQDs and y-Fe_(2)O_(3) effectively reduced the catalyst band gap(Eg),favoring the separation rate of electrons and holes,leading to remarkable efficient sulfamethoxazole(SMX)degradation as compared to the dark-CQDs@γ-Fe_(2)O_(3)/PDS and vis-γ-Fe_(2)O_(3)/PDS systems.The evolution of dissolved irons also demonstrated that CQDs could accelerate the in-situ reduction of surface-bounded Fe^(3+).Electron paramagnetic resonance(EPR)and radical scavenging experiments demonstrated that both*OH and SO_(4)·were generated in the reaction system,while*OH was relatively more dominant than SO_(4)·for SMX degradation.Finally,the reaction mechanism in the vis-CQDs@y-Fe_(2)O_(3)/PDS system was proposed involving an effective and accelerated heterogeneous-homogeneous iron cycle.CQDs would enrich the photo-generated electrons from y-Fe_(2)O_(3),causing efficient interfacial generation of surfacebond Fe^(2+)and reduction of adsorbed Fe3+.This visible light induced iron cycle would eventually lead to effective activation of PDS as well as the efficient degradation of SMX.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12494604,12393834,12393831,62274014,6223501662335015)the National Key R&D Program of China (Grant No.2024YFA1208900)。
文摘The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.
文摘As an important index to measure the degree of entanglement in quantum systems,concurrence plays an important role in practical research.In this paper,we study the concurrence between two qubits in triangular triple quantum dot structure.Through calculation and simulation,it is found that concurrence is mainly affected by the interdot coupling strength t,Coulomb interactionU,temperature T,and electrode coupling G.Through comparative studies with parallel triple quantum dot structures,we demonstrate that the triangular geometry exhibits significantly enhanced concurrence under identical conditions.In addition,under the condition that concurrence exceeds 0.9,the functional relationship between t and U is obtained through simulation,which provides theoretical support for quantum dot regulation under high entanglement.Finally,we demonstrate the feasibility of implementing a three-qubit quantum gate,using the Toffoli gate as a representative example,under the condition that the triangular triple quantum dot system maintains high entanglement.
基金supported by the Russian Science Foundation grant number 24-23-00481,https://rscf.ru/project/24-2300481/.
文摘Flexible materials with perovskite quantum dots(PQDs)are widely used in the field of photonics and opto-electronics due to their unique properties.Development of new materials based on these nanoparticles,incorporated into flexible and lightweight nonwoven fabrics,demonstrated high photoconductivity and efficient light energy conversion.In this work,we propose a method for creating a stable luminescent nonwoven material using electrospinning,in which inorganic salt precursors are used without the need for additional stabilizers.Equimolar solutions of cesium and lead(Ⅱ)bromide were mixed with a fluoroplast,resulting in a series of samples.Luminescent materials were obtained containing PQDs with a composition of CsPbBr_(3),with emission peaks ranging from 507 to 517 nm under 365-nm excitation.We have experimentally established and theoretically confirmed that the peak position is related to the size of the particles formed in the fiber during electrospinning and depends on processing time.Developed materials exhibited stable luminescent properties for up to 2.5 years,making them a promising candidate for the development of new flexible optoelectronic devices based on PQDs.
基金supported by the National Natural Science Foundation of China(Grant No.12305050)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Grant No.23KJB140017)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ25A050001)。
文摘Quantum dot systems emerge as promising platforms for studying nanoscale thermoelectric effects and quantum fluctuation phenomena.In this work,we investigate the thermodynamic performance of a Coulomb-blockaded quantum dot operating as a quantum heat engine using the quantum master equation approach.By incorporating full counting statistics,we analyze both average transport properties and current fluctuations in this nanoscale system.We demonstrate that electron-electron interactions significantly enhance thermoelectric performance by increasing both the output power and energy conversion efficiency.Furthermore,we show that Coulomb interactions suppress current fluctuations while preserving the validity of the thermodynamic uncertainty relation.Our results provide important insights into the interplay between quantum effects and thermodynamic principles in nanoscale heat engines.
基金the Department of Energy(DOE,Award Number:DE-FE0031997)for providing funds to support our research.
文摘Corn stover,an agricultural waste,was used to prepare nitrogen self-doped carbon quantum dots(CQDs)through a simple hydrothermal method with only water at near room temperature for the first time.The surface,electrochemical,and photovoltaic characteristics of CQDs doped TiO_(2)in dye-sensitized solar cells(DSSCs)were thoroughly and systematically examined.The average diameter of blue-fluorescence CQDs measured by a high-resolution transmission electron microscope(HR-TEM)was 4.63±0.87 nm,which consisted of polar functional groups.The highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)energy of the biomass-derived CQDs,determined by the cyclic voltammetry(CV)test,were,−5.48 eV and−3.89 eV,respectively.The negative shift of flat band potential(Vfb)in CQDs incorporated photoanode implies the fermi level shifted upward.Experimental results revealed that the improved performance of DSSCs was due to charge transport enhancement and separation,which resulted in the improved energy level configuration between TiO_(2),CQDs,and electrolytes.In this regard,the CQDs serve as a mediator that enables charge carrier transport without hindrance.In this study,CQDs added to TiO_(2)+N719,increased short circuit current density(JSC)and power conversion efficiency(PCE)value by∼26.00%(10.13 to 12.69 mA/cm^(2))and 27.20%(4.78%to 6.08%),respectively.
基金supported by (Dr. Manika Khanuja, Nanomission, (DST)[DST/NM/NB/2018/203(G) (JMI)]UGC grant (No.F.4(201-FRP)/2015 (BSR))
文摘The endocrine-disrupting chemicals(EDCs)and antibiotics are causing negative effects on human beings and animals by disrupting the endocrine system and spreading antimicrobial resistance.The current need is to eradicate pharmaceutical waste from water bodies using advanced catalytic systems with high efficiency.Novel ternary carbon quantum dots(CQDs)decorated Z-Scheme WS_(2)-PANI nanocomposite was prepared by a green synthesis assisted in-situ polymerization for the photodegradation and detection of Estradiol(EST)and Nitrofurantoin(NFT).HRTEM micrographs revealed the formation of CQDs with a mean size of 4nm anchored on the surface of WS_(2)/PANI(width:PANI~20-30nm).The ternary nanocomposite showed excellent photocatalytic activity,degraded NFT(95.7%in 60min),and EST(96.6%in 60min).The rate kinetics study confirms the reaction followed pseudo first-order model.This heterostructure exhibited enhanced performances by modulating the energy level configuration,enhancing the absorption of visible light(2.4eV),and significantly improving the charge separation,three times higher than pristine WS_(2).These are highly favorable for increasing the generation of photoinduced charges and enhancing the overall performance of the catalyst.Further,the electrochemical sensor was prepared using CQDs@WS_(2)/PANI nanocomposite on a paper-based electrode.The CQDs@WS_(2)/PANI exhibit a linear response of 0.1-100nM,with a limit of detection of 13nM.This synergistic interfacial interaction resulted in the significantly improved electrochemical performance of the modified electrode.The proposed Z-scheme was justified by electron paramagnetic resonance(EPR)and scavenger experiment.An intermediate degradation pathway was also proposed.The synthesized materials were characterized using FESEM,HRTEM,XRD,FTIR,XPS,UV-visible spectroscopy,PL,and TRPL.Therefore,this study provides a direct approach to fabricate a heterojunction that combines two-dimensional,one dimensional,and zero-dimensional properties,enabling control over the energy level configuration and subsequent improvements in photocatalytic and electrocatalytic efficiency.
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.
基金supported by the National Natural Science Foundation of China Project(No.52163001)the Guizhou Minzu University Research Platform Grant(No.GZMUGCZX[2021]01)+2 种基金the Guizhou Provincial Science and Technology Program Project Grant(Qiankehe Platform Talents-CXTD[2021]005,Qiankehe Platform Talents-GCC[2022]010-1,Qiankehe Fuqi[2023]001)the Central Guided Local Science and Technology Development Funds Project(Qiankehe Zhong Yindi[2023]035)the Doctor Startup Fund of Guizhou Minzu University(Grant No.GZMUZK[2024]QD77).
文摘Aqueous zinc ion batteries have received widespread attention.However,the growth of zinc dendrites and hydrogen evolution reaction generation seriously hinder the practical application of zinc ion bat-teries.Herein,it is reported that a multifunctional dendrites-free low-temperature PVA-based gel elec-trolyte by introducing negatively charged polymer carbon quantum dots(QDs)and the organic antifreeze dimethyl sulfoxide(DMSO)into it.The QDs carrying a large number of functional groups on the surface can effectively adsorb Zn^(2+),eliminating the“tip effect”,and inducing the uniform deposition of Zn^(2+)and the formation of a dendrites-free structure.Meanwhile,the solvation structure of adsorbed Zn^(2+)can be controlled by charged groups to reduce the generation of side reactions,thus obtaining high-performance zinc ion batteries.The Zn/polyaniline(PANi)full battery can be stably cycled more than 1000 times at-20℃,and the design of this gel electrolyte can provide good feasibility for safe,stable,and flexible energy storage devices.
文摘The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.
基金supported by the National Research Foundation of Korea(NRF)through a grant provided by the Korean government(No.NRF-2021R1F1A1063451).
文摘Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is a highly successful conductive polymer utilized as an electrode material in energy storage units for portable and wearable electronic de-vices.Nevertheless,employing PEDOT:PSS in supercapacitors(SC)in its pristine state presents challenges due to its suboptimal electrochemical performance and operational instability.To surmount these limita-tions,PEDOT:PSS has been integrated with carbon-based materials to form flexible electrodes,which ex-hibit physical and chemical stability during SC operation.We developed a streamlined fabrication process for high-performance SC electrodes composed of PEDOT:PSS and carbon quantum dots(CQDs).The CQDs were synthesized under microwave irradiation,yielding green-and red-light emissions.Through optimiz-ing the ratios of CQDs to PEDOT:PSS,the SC electrodes were prepared using a spray-coating technique,marking a significant improvement in device performance with a high volumetric capacitance(104.10 F cm-3),impressive energy density(19.68 Wh cm^(-3)),and excellent cyclic stability,retaining~85% of its original volumetric capacitance after 15,000 repeated GCD cycles.Moreover,the SCs,when utilized as a flexible substrate,demonstrated the ability to maintain up to~85% of their electrochemical performance even after 3,000 bending cycles(at a bending angle of 60°).These attributes render this hybrid composite an ideal candidate for a lightweight smart energy storage component in portable and wearable electronic technologies.
基金Project(52064032)supported by the National Natural Science Foundation of ChinaProjects(2019ZE001,202002AB080001)supported by the Yunnan Science and Technology Projects,ChinaProject(YNWR-QNBJ-2018-005)supported by the Yunnan Ten Thousand Talents Plan Young&Elite Talents,China。
文摘Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was prepared by powder metallurgy method.The composite powder was prepared by molecular blending method and ball milling method at first,and then densified into bulk material by spark plasma sintering(SPS).X-ray diffraction,Raman spectroscopy,infrared spectroscopy,and nuclear magnetic resonance were employed to characterize the CQD synthesized under different temperature conditions,and then CQDs with a higher degree of sp^(2)were utilized as the reinforcement to prepare composite materials with different contents.Mechanical properties and electrical conductivity results show that the tensile strength of the 0.2 CQD/Cu composite material is~31%higher than that of the pure copper sample,and the conductivity of 0.4 CQD/Cu is~96%IACS,which is as high as pure copper.TEM and HRTEM results show that good interface bonding of CQD and copper grain is the key to maintaining high mechanical and electrical conductivity.This research provides an important foundation and direction for new carbon materials reinforced metal matrix composites.
基金Sponsorship Program by CAST(2023QNRC001)University-Industry Collaborative Education Program(220901115200913,220901115201954)+2 种基金Hunan Provincial Natural Science Foundation of China(2022JJ40007)Jiangsu Agricultural Science and Technology Innovation Fund(CX(22)3047)the National Natural Science Foundation of China(32201491)。
文摘Carbon quantum dots are a new type of fluorescent nanomaterials with broad applications in drug delivery,bioimaging,solar cells,and photocatalysis due to their unique biocompatibility,optical properties and easy functionalization.In the meantime,because of its high carbon content,renewable nature,and environmental friendliness,lignin has drawn the attention of researchers as a desirable raw material for creating carbon quantum dots.Here we review the synthesis of carbon quantum dots from lignin,focusing on synthetic methods,properties,and applications in energy,and photocatalysis.Later,we propose some new development prospects from preparation methods,luminescence mechanism research,application,and commercial cost of lignin carbon quantum dots.Finally,based on this,the development prospects of this field are prospected and summarized.
基金supported by the National Natural Science Foundation of China(62374142,12175189 and 11904302)External Cooperation Program of Fujian(2022I0004)+1 种基金Fundamental Research Funds for the Central Universities(20720190005 and 20720220085)Major Science and Technology Project of Xiamen in China(3502Z20191015).
文摘The preparation of red,green,and blue quantum dot(QD)pixelated arrays with high precision,resolution,and brightness poses a significant challenge on the development of advanced micro-displays for virtual,augmented,and mixed reality applications.Alongside the controlled synthesis of high-performance QDs,a reliable QD patterning technology is crucial in overcoming this challenge.Among the various methods available,photolithography-based patterning technologies show great potentials in producing ultra-fine QD patterns at micron scale.This review article presents the recent advancements in the field of QD patterning using photolithography techniques and explores their applications in micro-display technology.Firstly,we discuss QD patterning through photolithography techniques employing photoresist(PR),which falls into two categories:PRassisted photolithography and photolithography of QDPR.Subsequently,direct photolithography techniques based on photo-induced crosslinking of photosensitive groups and photo-induced ligand cleavage mechanisms are thoroughly reviewed.Meanwhile,we assess the performance of QD arrays fabricated using these photolithography techniques and their integration into QD light emitting diode display devices as well as color conversionbased micro light emitting diode display devices.Lastly,we summarize the most recent developments in this field and outline future prospects.
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supported by the National Natural Science Foundation of China(Nos.62374142 and 22005255)Fundamental Research Funds for the Central Universities(Nos.20720220085 and 20720240064)+2 种基金External Cooperation Program of Fujian(No.2022I0004)Major Science and Technology Project of Xiamen in China(No.3502Z20191015)Xiamen Natural Science Foundation Youth Project(No.3502Z202471002)。
文摘Quantum dots(QDs),a type of nanoscale semiconductor material with unique optical and electrical properties like adjustable emission and high photoluminescence quantum yields,are suitable for applications in optoelectronics.However,QDs are typically degraded under humid and high-temperature circumstances,greatly limiting their practical value.Coating the QD surface with an inorganic silica layer is a feasible method for improving stability and endurance in a variety of applications.This paper comprehensively reviews silica coating methodologies on QD surfaces and explores their applications in optoelectronic domains.Firstly,the paper provides mainstream silica coating approaches,which can be divided into two categories:in-situ hydrolysis of silylating reagents on QD surfaces and template techniques for encapsulation QDs.Subsequently,the recent applications of the silica-coated QDs on optoelectronic fields including light-emitting diodes,solar cells,photodetectors were discussed.Finally,it reviews recent advances in silica-coated QD technology and prospects for future applications.
基金financial support from the Doctoral Foundation of Henan University of Engineering(No.D2022025)National Natural Science Foundation of China(No.U2004162)+1 种基金National Natural Science Foundation of China(No.52302138)Key Project for Science and Technology Development of Henan Province(No.232102320221)。
文摘With the rapid development of electric vehicles,hybrid electric vehicles and smart grids,people's demand for large-scale energy storage devices is increasingly intense.As a new type of secondary battery,potassium ion battery is promising to replace the lithium-ion battery in the field of large-scale energy storage by virtue of its low price and environmental friendliness.At present,the research on the anode materials of potassium ion batteries mainly focuses on carbon materials and the design of various nanostructured metal-based materials.Problems such as poor rate performance and inferior cycle life caused by electrode structure comminution during charge and discharge have not been solved.Quantum dots/nanodots materials are a new type of nanomaterials that can effectively improve the utilization of electrode materials and reduce production costs.In addition,quantum dots/nanodots materials can enhance the electrode reaction kinetics,reduce the stress generated in cycling,and effectively alleviate the agglomeration and crushing of electrode materials.In this review,we will systematically introduce the synthesis methods,K+storage properties and K+storage mechanisms of carbon quantum dots and carbon-based transition metal compound quantum dots composites.This review will have significant references for potassium ion battery researchers.
基金supported by the National Natural Science Foundation of China (No. 62204079)the Science and Technology Development Project of Henan Province (Nos.202300410048, 202300410057)+2 种基金the China Postdoctoral Science Foundation (No. 2022M711037)the Intelligence Introduction Plan of Henan Province in 2021 (No. CXJD2021008)Henan University Fund。
文摘Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.
基金supported by MEXT KAKENHI Grant(24K01295,26286013).
文摘Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachment and complex fabrication process introduce surface defects,compromising device stability and efficiency.In this work,we propose a solution-phase ligand exchange(SPLE)method utilizing inorganic ligands to develop stable p-type lead sulfide(PbS)CQD inks for the first time.Various amounts of tin(Ⅱ)iodide(SnI_(2))were mixed with lead halide(PbX_(2);X=I,Br)in the ligand solution.By precisely controlling the SnI_(2)concentration,we regulate the transition of PbS QDs from n-type to p-type.PbS CQDSCs were fabricated using two different HTL approaches:one with 1,2-ethanedithiol(EDT)-passivated QDs via the LbL method(control)and another with inorganic ligand-passivated QD ink(target).The target devices achieved a higher power conversion efficiency(PCE)of 10.93%,compared to 9.83%for the control devices.This improvement is attributed to reduced interfacial defects and enhanced carrier mobility.The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands,paving the way for high-performance and flexible CQD-based optoelectronic devices.
基金the National Natural Science Foundation of China(Nos.21677055,21407052)the Fundamental Research Funds for the Central Universities,Huazhong University of Science and Technology(HUST)(Nos.2017KFXKJC004,2016YXMS287)。
文摘In this study,a carbon quantum dots modified maghemite catalyst(CQDs@γ-Fe_(2)O_(3))has been synthesized by a one-step solvothermal method for efficient persulfate(PDS)activation under visible light irradiation.Transmission electron microscopy(TEM),scanning electron microscopy(SEM)and UV-vis diffuse reflectance spectroscopy(UV-vis DRS)characterization indicated that the formation of heterojunction structure between CQDs and y-Fe_(2)O_(3) effectively reduced the catalyst band gap(Eg),favoring the separation rate of electrons and holes,leading to remarkable efficient sulfamethoxazole(SMX)degradation as compared to the dark-CQDs@γ-Fe_(2)O_(3)/PDS and vis-γ-Fe_(2)O_(3)/PDS systems.The evolution of dissolved irons also demonstrated that CQDs could accelerate the in-situ reduction of surface-bounded Fe^(3+).Electron paramagnetic resonance(EPR)and radical scavenging experiments demonstrated that both*OH and SO_(4)·were generated in the reaction system,while*OH was relatively more dominant than SO_(4)·for SMX degradation.Finally,the reaction mechanism in the vis-CQDs@y-Fe_(2)O_(3)/PDS system was proposed involving an effective and accelerated heterogeneous-homogeneous iron cycle.CQDs would enrich the photo-generated electrons from y-Fe_(2)O_(3),causing efficient interfacial generation of surfacebond Fe^(2+)and reduction of adsorbed Fe3+.This visible light induced iron cycle would eventually lead to effective activation of PDS as well as the efficient degradation of SMX.
