The development of electrocatalysts that both work effectively at industrial current density and resist chloride ion(Cl^(-))corrosion remains a key challenge for hydrogen production from Cl^(-)-rich alkaline water.Her...The development of electrocatalysts that both work effectively at industrial current density and resist chloride ion(Cl^(-))corrosion remains a key challenge for hydrogen production from Cl^(-)-rich alkaline water.Herein,we report a CrO_(x)-engineered nickel-based oxide catalyst(FeCoCrO_(x)/NF)that achieves exceptional activity and stability through a dual-functional interfacial mechanism.Combing in situ Raman spectroscopy,18O isotopic labeling,and electrochemical analysis,we demonstrate that the oxygen evolution reaction follows a lattice oxygen-mediated mechanism.The CrO_(x)layer selectively adsorbs hydroxide ions,forming a dynamic interfacial barrier that electrostatically repels Cl^(-)ingress,thereby mitigating Cl^(-)corrosion.Through enthalpy-based analysis,we demonstrate that electronic redistribution via Cr-O-Fe bonding increases the vacancy formation energy of Fe,thereby suppressing its dissolution.In alkaline electrolyte containing 0.5 M Cl^(-)(1.0 M KOH),the catalyst is operating continuously for 1400 h at an industrial current density of 1000 mA cm^(-2).Furthermore,the catalyst retains 99.5%of its initial activity under fluctuating current density(100-1000 mA cm^(-2)),demonstrating robustness required for industrial electrolyzers.This study establishes a paradigm for designing corrosion-resistant electrocatalysts through the synergistic modulation of interfacial ion selectivity and bulk lattice oxygen activation,advancing the application of green hydrogen production in Cl^(-)-rich alkaline water.展开更多
Self-trapped excitons(STEs),known for their unique radiative properties,have been harnessed in diverse photonic devices;however,their comprehensive understanding and manipulation remain elusive.In this study,we presen...Self-trapped excitons(STEs),known for their unique radiative properties,have been harnessed in diverse photonic devices;however,their comprehensive understanding and manipulation remain elusive.In this study,we present novel experimental and theoretical evidence revealing the hybrid nature and optical tunability of STE state in Cs_(2)Ag_(0.4)Na_(0.6)InCl_(6).The detection of the Fano resonance in laser energy-dependent Raman and photoluminescence spectra indicates the emergence of an exciton-phonon hybrid state,arising from robust quantum interference between the discrete phonon and continuum exciton states.Moreover,we demonstrate continuous tuning of this hybrid state with the energy and intensity of the laser field.These findings lay the foundation for a comprehensive understanding of the nature of STE and their potential for state control.展开更多
A 2D electron-longitudinal-acoustic-phonon interaction Hamiltonian is derived and used to calculate the groundstate energy of the acoustic polarons in two dimensions. The numerical results for the ground-state energy ...A 2D electron-longitudinal-acoustic-phonon interaction Hamiltonian is derived and used to calculate the groundstate energy of the acoustic polarons in two dimensions. The numerical results for the ground-state energy of the acoustic polarons in two and three dimensions are obtained. The 3D results agree with those obtained by using the Feynman path-integral approach. It is found that the critical coupling constant of the transition from the quasifree state to the self-trapped state in the 2D case is much smaller than in the 3D case for a given cutoff wave-vector. The theory has been used to judge the possibility of the self-trapping for several real materials. The results indicate that the self-trappings of the electrons in AlN and the holes in AlN and GaN are expected to be observed in 2D systems.展开更多
Size-scalable X-ray scintillators with high transparency and robust photon yield allow for imaging large objects with greater precision and detail.Solution-processable scintillators,typically crafted from quantum dots...Size-scalable X-ray scintillators with high transparency and robust photon yield allow for imaging large objects with greater precision and detail.Solution-processable scintillators,typically crafted from quantum dots(QDs),are promising candidates for highly efficient scintillation applications.However,the restricted size and low transparency in QD-based scintillators lead to less efficient X-ray imaging for large objects requiring high resolution.Herein,we demonstrate a meter-scale ZnO QD scintillator with a visible range transmittance exceeding 96%,featuring bright singlet-triplet hybrid self-trapping excitons(STEs).The quantum yields(QYs)of singlet excitons and triplet excitons are 44.7%and 26.3%.Benefiting from a large Stokes shift and bright triplet excitons,the scintillator has a negligible self-absorption and elevated photon yields.Additionally,the scintillator exhibits exchange invariance,demonstrating identical optical performance upon exchanging the coordinates(r)of the QDs.Featuring bright singlet-triplet hybrid STEs and high transparency,the scintillator achieves high resolution X-ray imaging of 42-line pairs per millimeter(42 lp mm^(-1))at a meter scale.Moreover,demonstrations of 5000 cm^(2) X-ray imaging and real-time dynamic X-ray imaging are presented.The lowest detectable dose rate for X-ray detection is as low as 37.63±0.4 nGy s^(-1).This work presents a novel sizable and transparent scintillator with bright singlet-triplet hybrid STEs,showcasing their potential in high-resolution and sizable object X-ray imaging.展开更多
Layered organolead halides are an emerging class of self-trapped emitters,in which the unique corrugated structures are critical to afford out-of-plane distortions for self-trapping.However,the labile corner halide sp...Layered organolead halides are an emerging class of self-trapped emitters,in which the unique corrugated structures are critical to afford out-of-plane distortions for self-trapping.However,the labile corner halide species are often more exposed in corrugated layers,posing the trade-off relationship between structural corrugation and chemical robustness.展开更多
This was an outlook on the prediction of the infrared laser potentiality from concentration dependences of the 2F5/2 experimental decay time in Yb3＋-doped solid-state crystals mainly on cubic crystals with 99.99% pur...This was an outlook on the prediction of the infrared laser potentiality from concentration dependences of the 2F5/2 experimental decay time in Yb3＋-doped solid-state crystals mainly on cubic crystals with 99.99% purity which could be extended to laser ceramics of the same composition.展开更多
Low-dimensional lead-free metal halides with efficient self-trapped exciton(STE)emission have attracted tremendous attention in lighting applications.Despite great efforts in manipulating the STE emission properties,i...Low-dimensional lead-free metal halides with efficient self-trapped exciton(STE)emission have attracted tremendous attention in lighting applications.Despite great efforts in manipulating the STE emission properties,it is still a great challenge to achieve controllable STE emission tuning.Herein,we successfully synthesized novel one-dimensional(1D)β-Cs_(3)Cu_(2)Br_(5) with tunable emission color modulation from bluegreenish to yellow by alloying with different Ag contents.In particular.展开更多
Due to their environmental friendliness,structural plasticity,and tunable emission,lead-free halide double perovskites offer a broad spectrum of applications in light-emitting diode(LED),photodetectors,infrared imagin...Due to their environmental friendliness,structural plasticity,and tunable emission,lead-free halide double perovskites offer a broad spectrum of applications in light-emitting diode(LED),photodetectors,infrared imaging,and temperature sensing.Herein,we synthesized rare earth-based Cs_(2)NaYCl_(6)double perovskites using a solvothermal method,and Sb^(3+)/Sm^(3+)co-doping can effectively modulate the luminescence by adjusting the band gap structure and channels of energy transfer.With the Sm^(3+)-feeding concentration increasing,the emission could be adjusted from blue to white,attributed to an effective energy transfer from the self-trapped state to Sm^(3+).Temperature-dependent photoluminescence spectra indicate that the double self-trapped exciton emission at low temperatures originated from two minima in the excited state of 3P1.The relative sensitivity of the optical temperature sensor reached 1.08%K^(-1),which was better than that of other rare earth perovskites.The LED device based on Sb^(3+)/Sm^(3+)co-doped Cs_(2)NaYCl_(6)@polymethylmethacrylate displays a chromaticity coordinate of(0.29,0.28),a color rendering index of 87,and the correlated color temperature of 10986 K.Our work explores an in-depth understanding of energy transfer in double self-trapped states and provides new material for advanced applications.展开更多
The broadband emissions related to self-trapped excitons(STEs)have attracted considerable attention due to their potential wide application in optoelectronics.Yet,such materials require appropriate band gaps,which are...The broadband emissions related to self-trapped excitons(STEs)have attracted considerable attention due to their potential wide application in optoelectronics.Yet,such materials require appropriate band gaps,which are significantly related to the structural geometry.Herein,a new 3D lead chloride hybrid,(H_(2)MPP)_(2)Pb_(5)Cl_(14),where H_(2)MPP=1-methylpiperidinium-4-amine,consisting of face,corner and edgesharing lead chloride polyhedra,has been successfully isolated.Interestingly,in addition to its semiconducting properties,(H_(2)MPP)_(2)Pb_(5)Cl_(14) exhibits broadband white-red light emission with a large Stokes shift,a high color rendering index,and a nanosecond lifetime,which is mainly attributed to the STE mechanism.Moreover,(H_(2)MPP)_(2)Pb_(5)Cl_(14) exhibits higher stability under moisture,UV light and heat.展开更多
Zero-dimensional hybrid metal halides(0D HMHs)have sparked extensive research in the field of optoelectronic materials due to their unique physical and chemical properties.This work innovatively incorporates In^(3+)in...Zero-dimensional hybrid metal halides(0D HMHs)have sparked extensive research in the field of optoelectronic materials due to their unique physical and chemical properties.This work innovatively incorporates In^(3+)into a triphenyl-sulfide-based organic phosphorescent system,successfully constructing a novel 0D hybrid metal halide,(Ph_(3)S)_(2)InCl_(5).This new material achieves a synergistic output of blue photoluminescence(PL)and green afterglow,which originate from the intrinsic excitation of[Ph_(3)S]^(+).Through ns^(2) metal ion(Bi^(3+)/Sb^(3+))doping engineering,a dual-channel energy transfer pathway is established,enabling the transition from singlet and triplet states to self-trapped exciton states,thereby achieving dynamic control of fluorescence and phosphorescence emissions.Additionally,temperature-dependent PL spectra,time-resolved photoluminescence(TRPL),and Raman spectroscopy are employed to investigate the enhanced photoluminescence of the doped samples,revealing the process of STE(self-trapped excitons)recombination and the electron–phonon coupling processes.Based on these findings,a phosphorescence-PL dual-mode dynamic switching encryption system is constructed,utilizing a timeresolved multi-level decryption strategy to achieve high-order optical anti-counterfeiting.This work not only aids in the in-depth understanding of STE formation in In-based organic metal halides but also provides important guidance for the modulation strategy of STE and afterglow emissions in other 0D HMH luminescent materials.展开更多
Vacancy-ordered double perovskites(VODPs)have attracted much attention because of their excellent photoelectric properties.However,the competition mechanism of self-trapped exciton emission and Te^(4+)ion emission in ...Vacancy-ordered double perovskites(VODPs)have attracted much attention because of their excellent photoelectric properties.However,the competition mechanism of self-trapped exciton emission and Te^(4+)ion emission in Te^(4+)-doped VODPs is still unclear.Herein,we synthesized Rb_(2)HfCl_(6)microparticles with a blue self-trapped excitons(STEs)emission,which have a near-unity photoluminescence quantum yield(PLQY),the highest reported value(98.56%)for a VODP matrix.In addition,it has a new broadband yellow emission peak at 560 nm with a PLQY of 76.72%via the equivalent doping of Te^(4+)ions.The combination of the blue luminescence of pristine Rb_(2)HfCl_(6)with the yellow luminescence from the Te^(4+)ion emission could be used in fluorescence anti-counterfeiting.We also prepared a white light-emitting diode(WLED)with the Commission Internationale de l’Eclairage(CIE)coordinates at(0.3502,0.3527),a correlated color temperature(CCT)of 4814 K and a color^(-)rendering index(CRI)of 75.3.Moreover,optimized Rb_(2)HfCl_(6):Te^(4+)exhibited excellent air and thermal stability.The luminescence dynamics and theoretical calculations jointly reveal that this efficient emission originates from the electron transitions in the different paths.This work provides a new perspective and new theoretical support for the future research on ion-doped luminescent systems.展开更多
The origin of the electrical and optical properties of Cu-substituted NiO(Cu:NiO)polycrystalline bulks synthesized via a solid-state reaction is reported.The partial substitution of Ni sites with Cu led to a drastic d...The origin of the electrical and optical properties of Cu-substituted NiO(Cu:NiO)polycrystalline bulks synthesized via a solid-state reaction is reported.The partial substitution of Ni sites with Cu led to a drastic decrease of the electrical resistivity from 7.73×10^(8)to 6.51×10^(4)Ω·cm and a reduction in the energy for the self-trapping barrier from 0.58 to 0.24 eV in accordance with small polaron hopping conduction.展开更多
Conventional fluorescent anti-counterfeiting techniques are monolithic,however,most of them involve single-mode emission and are easily forged.Thus,it is especially important to develop efficient multi-modal fluoresce...Conventional fluorescent anti-counterfeiting techniques are monolithic,however,most of them involve single-mode emission and are easily forged.Thus,it is especially important to develop efficient multi-modal fluorescent anti-counterfeiting materials.Herein,we report a fluorescent material with double multicolor emission,Cs3 ZnI5:Mn^(2+)/Sn^(2+),that exhibits yellow-red emission at 555 nm and 690 nm under 405 nm laser excitation.Its temperature-dependent spectroscopic characteristics are used to investigate the effect of the thermal property and stability on the photoluminescence(PL)and structure of Cs_(3)ZnI_(5):Mn^(2+)/Sn^(2+),whose PL is mainly attributed to the^(3)P_(1)-^(1)S_(0)transition of the self-trapped exciton and^(4)T_(1)-^(6)A_(1)transitions of Mn^(2+).Under 360 nm laser excitation,the single crystals(SCs)show only red emission cen-tered at 670 nm,which has excitation wavelength-dependent properties and excellent thermal stability.The obtained materials are excitation wavelength-dependent,and this co-doping strategy promotes the application of novel metal halide materials in the fields of fluorescent anti-counterfeiting and information encryption/decryption.展开更多
Low-dimensional hybrid organic-inorganic metal halides(OIMHs)have been extensively investigated for their structural tunability and unique optoelectronic properties.However,the synthesis of highly photoluminescent lea...Low-dimensional hybrid organic-inorganic metal halides(OIMHs)have been extensively investigated for their structural tunability and unique optoelectronic properties.However,the synthesis of highly photoluminescent lead-free OIMHs remains challenging.To address this issue,we synthesized a series of hybrid OIMHs(DETA)_(3)InCl_(6):xSb^(3+)(DETA=diethylenetriamine,x=0-15%).With Sb^(3+)doping,the photoluminescence quantum yield(PLQY)is greatly improved from 4.84%to nearly 100%.Moreover,(DETA)_(3)InCl_(6):10%Sb^(3+)single crystals exhibit strong yellow broadband emission originating from selftrapped exciton(STE)radiative recombination.Interestingly,when Sb^(3+)doping is 0.005%,the single crystal doped Sb emits white light at an excitation wavelength of 365 nm with CIE coordinates of(0.35,0.36).We also explored the effect of Sb^(3+)dopants and STE state formation by DFT calculations and ultrafast transient absorption techniques.This research provides new insights into the design of high-performance photoluminescent materials based on hybrid metal halides.展开更多
The increasing demands in optoelectronic applications have driven the advancement of organic-inorganic hybrid metal halides(OIHMHs),owing to their exceptional optical transparency and high luminescence performance.In ...The increasing demands in optoelectronic applications have driven the advancement of organic-inorganic hybrid metal halides(OIHMHs),owing to their exceptional optical transparency and high luminescence performance.In this work,three zero-dimensional OIMH single crystals of(C_(7)H_(18)N_(2))MBr_(4)(C_(7)H_(18)N_(2)=1-propylpiperazine,M=Cd,Zn,and Mn)were prepared via a facile saturated crystallization method with adjustable luminescence properties.(C_(7)H_(18)N_(2))MnBr_(4) displays intensive green light emission with the highest photoluminescence yield(PLQY)of 54.93%originating from the d-d transition of Mn^(2+).Due to filled d orbital configurations of Zn^(2+)and Cd^(2+),(C_(7)H_(18)N_(2))CdBr_(4) and(C_(7)H_(18)N_(2))ZnBr_(4) exhibited blue light owing to their stronger self-trapped excitons(STEs)recombination.Furthermore,(C_(7)H_(18)N_(2))CdBr_(4) and(C_(7)H_(18)N_(2))ZnBr_(4) exhibited another red luminescence band after grinding,originating from defect-induced STEs.In addition,due to their excellent PL performance,the white LED fabricated based on(C_(7)H_(18)N_(2))MnBr_(4) and(C_(7)H_(18)N_(2))ZnBr_(4) has demonstrated a high color rendering index(CRI)of 88.2.This work not only provides a strategy for optimizing the photoluminescence performance by modulating metal ions within the same crystal structure of OIHMHs,but also provides insights into both intrinsic STE emission and the design of high-performance luminescent materials.展开更多
The emerged 3D APb_(2)X_(6)(A represents diammonium;X is Cl,Br and I)perovskitoids hold huge potential to inherit the desirable charge transport properties and functional tunability of 3D APbX3 perovskites.Limited by ...The emerged 3D APb_(2)X_(6)(A represents diammonium;X is Cl,Br and I)perovskitoids hold huge potential to inherit the desirable charge transport properties and functional tunability of 3D APbX3 perovskites.Limited by the Goldschmidt tolerance factor rule,the reported 3D perovskitoid species remain sparse,hindering us from exploring their structural effect dictated photoelectronic behavior.Herein,we construct novel 3D(NMDAP)Pb_(2)Br_(6)(NMDAP=N-methyl propane diammonium)composed of Pb_(2)Br_(10) dimer unit,modulated by methylated diammonium spacer and the synthetically controlled stoichiometric ratio of reactants.Significantly,3D(NMDAP)Pb_(2)Br_(6) shows remarkable self-trapped exciton(STE)emission induced by high octahedra distortion associated with strong electron–phonon coupling.The STE emission features broadband photoluminescence(PL)spectra ranging from 525 to 750 nm with a large Stokes redshift of∼0.91 eV.Photophysical investigation further reveals a large Huang–Rhys factor of∼146 and a long STE emission lifetime of 17 ns.DFT calculations suggest that the band edge states are mainly contributed by the Pb 6s/Br 4p orbitals along the equatorial direction rather than the axial direction in 3D(NMDAP)Pb_(2)Br_(6).Moreover,the asymmetric structure enables 3D(NMDAP)Pb_(2)Br_(6) anisotropic charge transport behavior,as underpinned by the experimental and theoretical investigations.As a consequence,a photoconductive detector based on 3D(NMDAP)Pb_(2)Br_(6) single crystal delivers anisotropic photoconductivity performance,with the[001]direction showing a responsivity and detectivity of 0.28 A W^(−1) and 2.12×10^(12) Jones,about 3-fold enhancement compared to those along the[100]and[010]directions.These observations offer extended functional tunability in 3D perovskitoids and reveal the potential of 3D perovskitoids in advanced optoelectronic devices.展开更多
基金supported by the National Nature Science Foundation of China under Grant No.22269021the Tianshan Talent Project of Xinjiang Uygur Autonomous Region:2023TSYCQNTJ0039the Open project of Key Laboratory in Xinjiang Uygur Autonomous Region of China:2023D04027。
文摘The development of electrocatalysts that both work effectively at industrial current density and resist chloride ion(Cl^(-))corrosion remains a key challenge for hydrogen production from Cl^(-)-rich alkaline water.Herein,we report a CrO_(x)-engineered nickel-based oxide catalyst(FeCoCrO_(x)/NF)that achieves exceptional activity and stability through a dual-functional interfacial mechanism.Combing in situ Raman spectroscopy,18O isotopic labeling,and electrochemical analysis,we demonstrate that the oxygen evolution reaction follows a lattice oxygen-mediated mechanism.The CrO_(x)layer selectively adsorbs hydroxide ions,forming a dynamic interfacial barrier that electrostatically repels Cl^(-)ingress,thereby mitigating Cl^(-)corrosion.Through enthalpy-based analysis,we demonstrate that electronic redistribution via Cr-O-Fe bonding increases the vacancy formation energy of Fe,thereby suppressing its dissolution.In alkaline electrolyte containing 0.5 M Cl^(-)(1.0 M KOH),the catalyst is operating continuously for 1400 h at an industrial current density of 1000 mA cm^(-2).Furthermore,the catalyst retains 99.5%of its initial activity under fluctuating current density(100-1000 mA cm^(-2)),demonstrating robustness required for industrial electrolyzers.This study establishes a paradigm for designing corrosion-resistant electrocatalysts through the synergistic modulation of interfacial ion selectivity and bulk lattice oxygen activation,advancing the application of green hydrogen production in Cl^(-)-rich alkaline water.
基金funding support from the National Natural Science Foundation of China(Grant No.12525405)funding support from the National Natural Science Foundation of China(Grant No.12393831)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-120)。
文摘Self-trapped excitons(STEs),known for their unique radiative properties,have been harnessed in diverse photonic devices;however,their comprehensive understanding and manipulation remain elusive.In this study,we present novel experimental and theoretical evidence revealing the hybrid nature and optical tunability of STE state in Cs_(2)Ag_(0.4)Na_(0.6)InCl_(6).The detection of the Fano resonance in laser energy-dependent Raman and photoluminescence spectra indicates the emergence of an exciton-phonon hybrid state,arising from robust quantum interference between the discrete phonon and continuum exciton states.Moreover,we demonstrate continuous tuning of this hybrid state with the energy and intensity of the laser field.These findings lay the foundation for a comprehensive understanding of the nature of STE and their potential for state control.
基金Project supported by the Doctoral Program Foundation of Institutions of Higher Education China （Grant No 20040126003） and the Natural Science Foundation of Inner Mongol of China （Grant No 200408020101）.
文摘A 2D electron-longitudinal-acoustic-phonon interaction Hamiltonian is derived and used to calculate the groundstate energy of the acoustic polarons in two dimensions. The numerical results for the ground-state energy of the acoustic polarons in two and three dimensions are obtained. The 3D results agree with those obtained by using the Feynman path-integral approach. It is found that the critical coupling constant of the transition from the quasifree state to the self-trapped state in the 2D case is much smaller than in the 3D case for a given cutoff wave-vector. The theory has been used to judge the possibility of the self-trapping for several real materials. The results indicate that the self-trappings of the electrons in AlN and the holes in AlN and GaN are expected to be observed in 2D systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.62075198,11974317,61804136)the Outstanding Youth Foundation of Henan(Grant nos.222300420087)S.-Y.S.acknowledges the support from the National Postdoctoral Program for Innovative Talents(Grant No.BX20240337).
文摘Size-scalable X-ray scintillators with high transparency and robust photon yield allow for imaging large objects with greater precision and detail.Solution-processable scintillators,typically crafted from quantum dots(QDs),are promising candidates for highly efficient scintillation applications.However,the restricted size and low transparency in QD-based scintillators lead to less efficient X-ray imaging for large objects requiring high resolution.Herein,we demonstrate a meter-scale ZnO QD scintillator with a visible range transmittance exceeding 96%,featuring bright singlet-triplet hybrid self-trapping excitons(STEs).The quantum yields(QYs)of singlet excitons and triplet excitons are 44.7%and 26.3%.Benefiting from a large Stokes shift and bright triplet excitons,the scintillator has a negligible self-absorption and elevated photon yields.Additionally,the scintillator exhibits exchange invariance,demonstrating identical optical performance upon exchanging the coordinates(r)of the QDs.Featuring bright singlet-triplet hybrid STEs and high transparency,the scintillator achieves high resolution X-ray imaging of 42-line pairs per millimeter(42 lp mm^(-1))at a meter scale.Moreover,demonstrations of 5000 cm^(2) X-ray imaging and real-time dynamic X-ray imaging are presented.The lowest detectable dose rate for X-ray detection is as low as 37.63±0.4 nGy s^(-1).This work presents a novel sizable and transparent scintillator with bright singlet-triplet hybrid STEs,showcasing their potential in high-resolution and sizable object X-ray imaging.
基金supported by grants from the National Natural Science Foundation of China(21971197 and 22171214)the Shanghai Rising-Star Program(20QA1409500)+1 种基金the Natural Science Foundation of Shanghai(22ZR1463200)the Recruitment of Global Youth Experts by China and the Science&Technology Commission of Shanghai Municipality(19DZ2271500).
文摘Layered organolead halides are an emerging class of self-trapped emitters,in which the unique corrugated structures are critical to afford out-of-plane distortions for self-trapping.However,the labile corner halide species are often more exposed in corrugated layers,posing the trade-off relationship between structural corrugation and chemical robustness.
文摘This was an outlook on the prediction of the infrared laser potentiality from concentration dependences of the 2F5/2 experimental decay time in Yb3＋-doped solid-state crystals mainly on cubic crystals with 99.99% purity which could be extended to laser ceramics of the same composition.
基金supported by the Taishan Scholar Project of Shandong Province of China,the Scientific Research Starting Foundation of Outstanding Young Scholars of Shandong University,the National Natural Science Foundation of China(grant no.22103050)the Young Scholars Future Program of Shandong University.
文摘Low-dimensional lead-free metal halides with efficient self-trapped exciton(STE)emission have attracted tremendous attention in lighting applications.Despite great efforts in manipulating the STE emission properties,it is still a great challenge to achieve controllable STE emission tuning.Herein,we successfully synthesized novel one-dimensional(1D)β-Cs_(3)Cu_(2)Br_(5) with tunable emission color modulation from bluegreenish to yellow by alloying with different Ag contents.In particular.
基金supported by the National Natural Science Foundation of China(Grant No.52162021 and 22175043)Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures(Grant No.MMCS2023OF05)Guangxi Science and Technology Plan Project(Guike AA23073018).
文摘Due to their environmental friendliness,structural plasticity,and tunable emission,lead-free halide double perovskites offer a broad spectrum of applications in light-emitting diode(LED),photodetectors,infrared imaging,and temperature sensing.Herein,we synthesized rare earth-based Cs_(2)NaYCl_(6)double perovskites using a solvothermal method,and Sb^(3+)/Sm^(3+)co-doping can effectively modulate the luminescence by adjusting the band gap structure and channels of energy transfer.With the Sm^(3+)-feeding concentration increasing,the emission could be adjusted from blue to white,attributed to an effective energy transfer from the self-trapped state to Sm^(3+).Temperature-dependent photoluminescence spectra indicate that the double self-trapped exciton emission at low temperatures originated from two minima in the excited state of 3P1.The relative sensitivity of the optical temperature sensor reached 1.08%K^(-1),which was better than that of other rare earth perovskites.The LED device based on Sb^(3+)/Sm^(3+)co-doped Cs_(2)NaYCl_(6)@polymethylmethacrylate displays a chromaticity coordinate of(0.29,0.28),a color rendering index of 87,and the correlated color temperature of 10986 K.Our work explores an in-depth understanding of energy transfer in double self-trapped states and provides new material for advanced applications.
基金supported by the National Natural Science Foundation of China(No.21971203)the Key Scientific and Technological Innovation Team of Shaanxi Province(No.2020TD-001)+1 种基金the Fundamental Research Funds for Central Universities,State Key Laboratory of Electrical Insulation and Power Equipment(No.EIPE23409)the Instrument Analysis Center of Xi’an Jiaotong University for assistance.
文摘The broadband emissions related to self-trapped excitons(STEs)have attracted considerable attention due to their potential wide application in optoelectronics.Yet,such materials require appropriate band gaps,which are significantly related to the structural geometry.Herein,a new 3D lead chloride hybrid,(H_(2)MPP)_(2)Pb_(5)Cl_(14),where H_(2)MPP=1-methylpiperidinium-4-amine,consisting of face,corner and edgesharing lead chloride polyhedra,has been successfully isolated.Interestingly,in addition to its semiconducting properties,(H_(2)MPP)_(2)Pb_(5)Cl_(14) exhibits broadband white-red light emission with a large Stokes shift,a high color rendering index,and a nanosecond lifetime,which is mainly attributed to the STE mechanism.Moreover,(H_(2)MPP)_(2)Pb_(5)Cl_(14) exhibits higher stability under moisture,UV light and heat.
基金the financial support from the Heilongjiang Provincial Key Laboratory of Micro-nano Sensitive Devices and Systems(Heilongjiang University)the Basic Research Project for Outstanding Young Teachers of Heilongjiang Province(YQJH2023128)the Cultivation Project of Double First-class Initiative Discipline by Heilongjiang Province(LJGXCG2022-061).
文摘Zero-dimensional hybrid metal halides(0D HMHs)have sparked extensive research in the field of optoelectronic materials due to their unique physical and chemical properties.This work innovatively incorporates In^(3+)into a triphenyl-sulfide-based organic phosphorescent system,successfully constructing a novel 0D hybrid metal halide,(Ph_(3)S)_(2)InCl_(5).This new material achieves a synergistic output of blue photoluminescence(PL)and green afterglow,which originate from the intrinsic excitation of[Ph_(3)S]^(+).Through ns^(2) metal ion(Bi^(3+)/Sb^(3+))doping engineering,a dual-channel energy transfer pathway is established,enabling the transition from singlet and triplet states to self-trapped exciton states,thereby achieving dynamic control of fluorescence and phosphorescence emissions.Additionally,temperature-dependent PL spectra,time-resolved photoluminescence(TRPL),and Raman spectroscopy are employed to investigate the enhanced photoluminescence of the doped samples,revealing the process of STE(self-trapped excitons)recombination and the electron–phonon coupling processes.Based on these findings,a phosphorescence-PL dual-mode dynamic switching encryption system is constructed,utilizing a timeresolved multi-level decryption strategy to achieve high-order optical anti-counterfeiting.This work not only aids in the in-depth understanding of STE formation in In-based organic metal halides but also provides important guidance for the modulation strategy of STE and afterglow emissions in other 0D HMH luminescent materials.
基金supported by the National Natural Science Foundation of China(No.51352002 and 12074195).
文摘Vacancy-ordered double perovskites(VODPs)have attracted much attention because of their excellent photoelectric properties.However,the competition mechanism of self-trapped exciton emission and Te^(4+)ion emission in Te^(4+)-doped VODPs is still unclear.Herein,we synthesized Rb_(2)HfCl_(6)microparticles with a blue self-trapped excitons(STEs)emission,which have a near-unity photoluminescence quantum yield(PLQY),the highest reported value(98.56%)for a VODP matrix.In addition,it has a new broadband yellow emission peak at 560 nm with a PLQY of 76.72%via the equivalent doping of Te^(4+)ions.The combination of the blue luminescence of pristine Rb_(2)HfCl_(6)with the yellow luminescence from the Te^(4+)ion emission could be used in fluorescence anti-counterfeiting.We also prepared a white light-emitting diode(WLED)with the Commission Internationale de l’Eclairage(CIE)coordinates at(0.3502,0.3527),a correlated color temperature(CCT)of 4814 K and a color^(-)rendering index(CRI)of 75.3.Moreover,optimized Rb_(2)HfCl_(6):Te^(4+)exhibited excellent air and thermal stability.The luminescence dynamics and theoretical calculations jointly reveal that this efficient emission originates from the electron transitions in the different paths.This work provides a new perspective and new theoretical support for the future research on ion-doped luminescent systems.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2019R1A6A1A11055660)It was also partly supported by the MEXT,Element Strategy Initiative to form a research core.M.S.O.acknowledges the National Research Foundation of Korea(NRF)Grant funded by the Ministry of Science and ICT for the First-Mover Program for Accelerating Disruptive Technology Development(NRF-2018M3C1B9088458)S.L.was supported by the National Research Foundation of Korea through NRF-2019M3F3A1A02072175.We also thank Prof.H.Lei for valuable discussions.
文摘The origin of the electrical and optical properties of Cu-substituted NiO(Cu:NiO)polycrystalline bulks synthesized via a solid-state reaction is reported.The partial substitution of Ni sites with Cu led to a drastic decrease of the electrical resistivity from 7.73×10^(8)to 6.51×10^(4)Ω·cm and a reduction in the energy for the self-trapping barrier from 0.58 to 0.24 eV in accordance with small polaron hopping conduction.
基金support from the Heilongjiang Provincial Key Laboratory of Micro-nano Sensitive Devices and Systems(Heilongjiang University)Basic Research Project for Outstanding Young Teachers of Heilongjiang Province(YQJH2023128)Cultivation Project of Double First-class Initiative Discipline by Heilongjiang Province(LJGXCG2022-061).
文摘Conventional fluorescent anti-counterfeiting techniques are monolithic,however,most of them involve single-mode emission and are easily forged.Thus,it is especially important to develop efficient multi-modal fluorescent anti-counterfeiting materials.Herein,we report a fluorescent material with double multicolor emission,Cs3 ZnI5:Mn^(2+)/Sn^(2+),that exhibits yellow-red emission at 555 nm and 690 nm under 405 nm laser excitation.Its temperature-dependent spectroscopic characteristics are used to investigate the effect of the thermal property and stability on the photoluminescence(PL)and structure of Cs_(3)ZnI_(5):Mn^(2+)/Sn^(2+),whose PL is mainly attributed to the^(3)P_(1)-^(1)S_(0)transition of the self-trapped exciton and^(4)T_(1)-^(6)A_(1)transitions of Mn^(2+).Under 360 nm laser excitation,the single crystals(SCs)show only red emission cen-tered at 670 nm,which has excitation wavelength-dependent properties and excellent thermal stability.The obtained materials are excitation wavelength-dependent,and this co-doping strategy promotes the application of novel metal halide materials in the fields of fluorescent anti-counterfeiting and information encryption/decryption.
基金supported by the National Natural Science Foundation of China(22275075)the Natural Science Foundation of Jiangxi Province(20204BCJ22015 and 20202ACBL203001)the Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(20212BCD42018).
文摘Low-dimensional hybrid organic-inorganic metal halides(OIMHs)have been extensively investigated for their structural tunability and unique optoelectronic properties.However,the synthesis of highly photoluminescent lead-free OIMHs remains challenging.To address this issue,we synthesized a series of hybrid OIMHs(DETA)_(3)InCl_(6):xSb^(3+)(DETA=diethylenetriamine,x=0-15%).With Sb^(3+)doping,the photoluminescence quantum yield(PLQY)is greatly improved from 4.84%to nearly 100%.Moreover,(DETA)_(3)InCl_(6):10%Sb^(3+)single crystals exhibit strong yellow broadband emission originating from selftrapped exciton(STE)radiative recombination.Interestingly,when Sb^(3+)doping is 0.005%,the single crystal doped Sb emits white light at an excitation wavelength of 365 nm with CIE coordinates of(0.35,0.36).We also explored the effect of Sb^(3+)dopants and STE state formation by DFT calculations and ultrafast transient absorption techniques.This research provides new insights into the design of high-performance photoluminescent materials based on hybrid metal halides.
基金support from the National Natural Science Foundation of China(22171105,22471096)the Shandong Provincial Natural Science Foundation(ZR2021MB001,ZR2024QA231,ZR2023QB270)the Young Innovative Team Project for Colleges and Universities of Shandong Province(2024KJH053).
文摘The increasing demands in optoelectronic applications have driven the advancement of organic-inorganic hybrid metal halides(OIHMHs),owing to their exceptional optical transparency and high luminescence performance.In this work,three zero-dimensional OIMH single crystals of(C_(7)H_(18)N_(2))MBr_(4)(C_(7)H_(18)N_(2)=1-propylpiperazine,M=Cd,Zn,and Mn)were prepared via a facile saturated crystallization method with adjustable luminescence properties.(C_(7)H_(18)N_(2))MnBr_(4) displays intensive green light emission with the highest photoluminescence yield(PLQY)of 54.93%originating from the d-d transition of Mn^(2+).Due to filled d orbital configurations of Zn^(2+)and Cd^(2+),(C_(7)H_(18)N_(2))CdBr_(4) and(C_(7)H_(18)N_(2))ZnBr_(4) exhibited blue light owing to their stronger self-trapped excitons(STEs)recombination.Furthermore,(C_(7)H_(18)N_(2))CdBr_(4) and(C_(7)H_(18)N_(2))ZnBr_(4) exhibited another red luminescence band after grinding,originating from defect-induced STEs.In addition,due to their excellent PL performance,the white LED fabricated based on(C_(7)H_(18)N_(2))MnBr_(4) and(C_(7)H_(18)N_(2))ZnBr_(4) has demonstrated a high color rendering index(CRI)of 88.2.This work not only provides a strategy for optimizing the photoluminescence performance by modulating metal ions within the same crystal structure of OIHMHs,but also provides insights into both intrinsic STE emission and the design of high-performance luminescent materials.
基金supported by the National Natural Science Foundation of China(Grant 21805075,62274057)the Sino-German Mobility Program(Grant No.M-0764)+1 种基金the Natural Science Foundation of Hubei Province(Grant No.2022EHB023)the Educational Commission of Hubei Province of China(Grant D20211001).
文摘The emerged 3D APb_(2)X_(6)(A represents diammonium;X is Cl,Br and I)perovskitoids hold huge potential to inherit the desirable charge transport properties and functional tunability of 3D APbX3 perovskites.Limited by the Goldschmidt tolerance factor rule,the reported 3D perovskitoid species remain sparse,hindering us from exploring their structural effect dictated photoelectronic behavior.Herein,we construct novel 3D(NMDAP)Pb_(2)Br_(6)(NMDAP=N-methyl propane diammonium)composed of Pb_(2)Br_(10) dimer unit,modulated by methylated diammonium spacer and the synthetically controlled stoichiometric ratio of reactants.Significantly,3D(NMDAP)Pb_(2)Br_(6) shows remarkable self-trapped exciton(STE)emission induced by high octahedra distortion associated with strong electron–phonon coupling.The STE emission features broadband photoluminescence(PL)spectra ranging from 525 to 750 nm with a large Stokes redshift of∼0.91 eV.Photophysical investigation further reveals a large Huang–Rhys factor of∼146 and a long STE emission lifetime of 17 ns.DFT calculations suggest that the band edge states are mainly contributed by the Pb 6s/Br 4p orbitals along the equatorial direction rather than the axial direction in 3D(NMDAP)Pb_(2)Br_(6).Moreover,the asymmetric structure enables 3D(NMDAP)Pb_(2)Br_(6) anisotropic charge transport behavior,as underpinned by the experimental and theoretical investigations.As a consequence,a photoconductive detector based on 3D(NMDAP)Pb_(2)Br_(6) single crystal delivers anisotropic photoconductivity performance,with the[001]direction showing a responsivity and detectivity of 0.28 A W^(−1) and 2.12×10^(12) Jones,about 3-fold enhancement compared to those along the[100]and[010]directions.These observations offer extended functional tunability in 3D perovskitoids and reveal the potential of 3D perovskitoids in advanced optoelectronic devices.
