Zero mass flux jets, synthesized by acoustic actuators, have been used for the purpose of jet mixing enhancement and jet vectoring. Zero mass flux jets composed of entirely entrained fluid allow momentum transfer into...Zero mass flux jets, synthesized by acoustic actuators, have been used for the purpose of jet mixing enhancement and jet vectoring. Zero mass flux jets composed of entirely entrained fluid allow momentum transfer into the embedding flow. In the present experiments, miniature scale high aspect ratio actuator jets are placed along the long sides and near the exit plane of a primary two dimensional jet. In different modes, the primary jet can be vectored either towards or away from the actuator jets and the jet mixing is enhanced. The disturbance of the excitation frequency is developed while the unstable frequency of the primary jet is completely suppressed.展开更多
This research proposes a novel three-dimensional gravity inversion based on sparse recovery in compress sensing. Zero norm is selected as the objective function, which is then iteratively solved by the approximate zer...This research proposes a novel three-dimensional gravity inversion based on sparse recovery in compress sensing. Zero norm is selected as the objective function, which is then iteratively solved by the approximate zero norm solution. The inversion approach mainly employs forward modeling; a depth weight function is introduced into the objective function of the zero norms. Sparse inversion results are obtained by the corresponding optimal mathematical method. To achieve the practical geophysical and geological significance of the results, penalty function is applied to constrain the density values. Results obtained by proposed provide clear boundary depth and density contrast distribution information. The method's accuracy, validity, and reliability are verified by comparing its results with those of synthetic models. To further explain its reliability, a practical gravity data is obtained for a region in Texas, USA is applied. Inversion results for this region are compared with those of previous studies, including a research of logging data in the same area. The depth of salt dome obtained by the inversion method is 4.2 km, which is in good agreement with the 4.4 km value from the logging data. From this, the practicality of the inversion method is also validated.展开更多
The toxicity and degradation of hybrid lead-halide perovskites hinder their extensive applications.It is thus of great importance to explore non-toxic alternative materials with excellent stability and optoelectronic ...The toxicity and degradation of hybrid lead-halide perovskites hinder their extensive applications.It is thus of great importance to explore non-toxic alternative materials with excellent stability and optoelectronic property.We investigate the atomic structures and optoelectronic properties of non-toxic organic tin bromide perovskites(OTBP)with one/zerodimensional(1D/0D)structures by first-principles calculations.The calculated atomic structures show that the 1D/0D OTBPs are stable and the structure of inorganic octahedra in 0D is higher order than that in 1D.Moreover,the origination of exceptional purity emitting light in experiments is explained based on the calculated electronic structure.展开更多
Zero-dimensional(0D)lead-free all-inorganic metal halides have emerged as next-generation photoluminescent(PL)materials in recent years because of their extraordinary PL properties,non-toxicity,and high stability.Here...Zero-dimensional(0D)lead-free all-inorganic metal halides have emerged as next-generation photoluminescent(PL)materials in recent years because of their extraordinary PL properties,non-toxicity,and high stability.Herein,a green,high stability,all-inorganic Rb_(2)CsBiCl_(6) single crystal with 0D structure was grown as a new PL material.Strikingly,using the antimony doping strategy,the broad yellow emission of Rb_(2)CsBiCl_(6) was significantly enhanced due to the enhanced absorption in the UV region,and the PL quantum yield was increased from 1%to 45%at room temperature.Furthermore,the fluorescent mechanism was revealed by the combination of optical characterizations and first-principles calculations.展开更多
This work explores the utilization of a photoactive organic cation for the preparation of R_(2)MCl_(4)(M=Zn,Cd;R=(E)-4-styrylpyridinium,C_(13)H_(12)N^(+)).The zero-dimensional crystal structures of R_(2)MCl_(4)contain...This work explores the utilization of a photoactive organic cation for the preparation of R_(2)MCl_(4)(M=Zn,Cd;R=(E)-4-styrylpyridinium,C_(13)H_(12)N^(+)).The zero-dimensional crystal structures of R_(2)MCl_(4)contain isolated tetrahedral anions[MCl_(4)]_(2)-separated by the organic cations R+,leading to flat bands around the optical band gap.In R_(2)MCl_(4),the inorganic band gaps are sufficiently large to accommodate the organic molecular levels within,and therefore,the optical properties of R_(2)MCl_(4)are determined by the organic cation.Our combined optical spectroscopy and density functional theory(DFT)studies confirm the attribution of the bright green photoluminescence demonstrated by R_(2)MCl_(4)to the organic molecular emission.Importantly,the incorporation of the photoemissive organic cation R+into the hybrid framework in R_(2)MCl_(4)leads to a nearly two-fold enhancement of the light emission efficiency with the measured photoluminescence quantum yield(PLQY)values of 6.04%,10.40%and 11.21% for RCl,R_(2)ZnCl_(4)and R_(2)CdCl_(4),respectively.In addition,the crystal structure of the hybrid R_(2)MCl_(4)ensures a stabilized PL emission,preventing the occurrence of the harmful organic photodimerization,which is a notorious problem for this class of organic emitters.展开更多
Developing new birefringent materials with large optical anisotropy is extremely urgent due to the fantastic progress of laser science and technology.Here,two tin(Ⅱ)-based oxalates,K_(2)Sn(C_(2)O_(4))_(2)·H_(2)O...Developing new birefringent materials with large optical anisotropy is extremely urgent due to the fantastic progress of laser science and technology.Here,two tin(Ⅱ)-based oxalates,K_(2)Sn(C_(2)O_(4))_(2)·H_(2)O and K_(2)Sn_(2)(C_(2)O_(4))_(2)F_(2)·H_(2)O,were successfully synthesized by simultaneously introducingπ-conjugated[C_(2)O_(4)]^(2)-groups and distorted Sn^(2+)-polyhedra with stereochemically active lone pairs.展开更多
Organic-inorganic hybrid ferroelectric materials have attracted much attention due to their structural tunability and functional versatility.While lone-pair stereochemical activity in elements such as Sb,Bi,and Pb has...Organic-inorganic hybrid ferroelectric materials have attracted much attention due to their structural tunability and functional versatility.While lone-pair stereochemical activity in elements such as Sb,Bi,and Pb has been widely used to design ferroelectrics,Ge^(2+)with a polar 4s^(2) lone-pair remains underexplored.Herein,a novel zero-dimensional hybrid ferroelectric[(CH_(3))4N]GeBr_(3)(1)was successfully synthesized by utilizing the stereochemically active lone pair of Ge^(2+).Compound 1 exhibits remarkable ferroelectric characteristics,including a large spontaneous polarization(P_(s)=4.80μC cm^(-2))and a low coercive field(E_(c)=5.20 kV cm^(-1)).Moreover,the experimental results demonstrate that 1 undergoes dual structural phase transitions at 236 K and 445 K.The low temperature phase transition at 236 K belongs to the mmmFmm2-type ferroelectric phase transition.Remarkably,1 undergoes a reconfiguration phase transition at 445 K,accompanied by the dimensional transformation from zero-dimensional to pseudo-threedimensional architecture and giant dielectric switching behaviour.This work establishes new structure-property correlations in hybrid ferroelectrics while uncovering emergent technological potential in smart switching devices.展开更多
Zero-dimensional(0D)metal halide clusters formed as isolated metal halide polyhedral structures show excellent optical properties and have great potential for various applications in optoelectronic devices.In this stu...Zero-dimensional(0D)metal halide clusters formed as isolated metal halide polyhedral structures show excellent optical properties and have great potential for various applications in optoelectronic devices.In this study,we reported a series of Rb_(8)CuB(III)_(3)Cl_(18)single crystals(SCs)constructed from Cu(I)and B(III)(B=In,Tb,etc.)containing lead-free bimetallic halide clusters.展开更多
Zero-dimensional(0D)lead-free perovskites have garnered significant attention due to their unique optoelectronic properties and non-toxicity.However,the single response to stimuli in lead-free perovskites limits the v...Zero-dimensional(0D)lead-free perovskites have garnered significant attention due to their unique optoelectronic properties and non-toxicity.However,the single response to stimuli in lead-free perovskites limits the versatility of multifunctional compounds.In this study,we abandoned the toxic bromic acid and utilized water as the reaction medium,to achieve an environmentally friendly green chemical route.We successfully prepared a zero-dimensional lead-free halide Cs_(2)In_(1−x)Sb_(x)Br_(5)(H_(2)O)perovskite with a fractal structure using an in situ solution crystallization method.Herein,we discovered that the recrystallization occurred beneath the smooth-grown rhombic crystal surface,forming fractal branched crystals.Interestingly,reversible luminescence color transitions from orange-red to yellow and return to the initial state were achieved in response to the individual stimuli of temperature and humidity.We found that H_(2)O molecules played a crucial role in the color tuning,enabling reversible“on–off”switching modes with rapid modulation rates.Moreover,the 0D lead-free halide perovskite Cs_(2)InBr_(5)(H_(2)O):Sb^(3+)also exhibited excellent temperature sensitivity,with the relative sensitivity(SR)reaching up to 9.39%K^(−1).This study provides valuable insights for the further development of halide perovskites in design and application fields,laying a foundation for the development of multifunctional smart materials and temperature sensing applications.展开更多
A series of chalcogenide compounds with various compositions,i.e.,octanuclear or tetranuclear Zn-S clusters,have been synthesised in a straighforward manner.Different fused-ring aromatic ligands were used as capping l...A series of chalcogenide compounds with various compositions,i.e.,octanuclear or tetranuclear Zn-S clusters,have been synthesised in a straighforward manner.Different fused-ring aromatic ligands were used as capping ligands and the corresponding zero-dimensional(0D)products were obtained.On the other hand,use of bridging ligands led to a family of one-dimensional(1D)coordination polymers,and an in situ ligand reaction has been observed in[Zn_(8)S(SC_(6)H_(5))_(13)L_(1)(H_(2)O)]·2H_(2)O(L=3-carboxypryidyl)due to the hydrolysis of the cyano group of 3-pyridinecarbonitrile.A very rare 1D helical-chain structure was observed in[Zn_(4)(SC_(6)H_(5))_(8)L_(1)](L=4,4’-bipyridyl),providing evidence of the character of bridging organic ligands in the corresponding crystalline materials.First-principles calculations on[Zn_(4)(SC_(6)H_(5))_(8)L_(1)](L=4,4’-bipyridyl)further revealed that the two cluster units could rotate freely about the C-C single bond over a broad range,eventually leading to the formation of a one-dimensional helical structure.展开更多
Zero-dimensional(0D)cuprous organic–inorganic hybrid halides have emerged as a new kind of scintillator due to their high light yield and adjustable emission properties in the whole visible spectral range.However,the...Zero-dimensional(0D)cuprous organic–inorganic hybrid halides have emerged as a new kind of scintillator due to their high light yield and adjustable emission properties in the whole visible spectral range.However,their practical application in the radiation industry is seriously hindered by the instability of CuⅠ ions under humid atmospheres and oxidizing environments.Herein,we designed a new Cu(Ⅰ)-based halide of[CEOMTPP]_(2)Cu_(4)Br_(6)(CEOMTPP=ethoxycarbonylmethyl(triphenyl)phosphonium cation)containing a discrete[Cu_(4)Br_(6)]_(2)−nanocluster,which displays strong broadband yellow light emission with near-unity photoluminescence quantum yield(PLQY)and large Stokes shift of 206 nm.Remarkably,[CEOMTPP]_(2)Cu_(4)Br_(6) shows ultra-high anti-water and anti-oxidation stability with steady emitting performance in water for over one year and in an acid–base aqueous solution for one day.Benefiting from the near-unity PLQY,large Stokes shift and negligible self-absorption,[CEOMTPP]_(2)Cu_(4)Br_(6) exhibits excellent scintillation properties with a high light yield of 69500 phonon per meV and low detection limit of 113.0 nGy s^(−1).Furthermore,a high spatial resolution of 14.5 lp mm^(−1) is achieved in X-ray imaging based on a[CEOMTPP]_(2)Cu_(4)Br_(6)@EVA composite-assembled scintillation screen,demonstrating its potential application in medical photography.This research provides a fundamental structural engineering strategy to design highly efficient and stable low-dimensional Cu(Ⅰ)halides for X-ray radiation application.展开更多
Low-dimensional metal halides have emerged as promising platforms for the development of new-generation phosphor-converted light emitting diodes(pc-LEDs),in which zero-dimensional(0D)hybrids with lone-pair ns_(2)state...Low-dimensional metal halides have emerged as promising platforms for the development of new-generation phosphor-converted light emitting diodes(pc-LEDs),in which zero-dimensional(0D)hybrids with lone-pair ns_(2)states,in particular,show unprecedented competitiveness owing to their fascinating photoluminescence(PL)properties.展开更多
Chiral defect-induced strategy is employed to synthesize zero-dimensional(0D)chiral Cs_(4)PbBr_(6) perovskite nanocrystals(NCs)with blue photoluminescence via a phase transition process.The chirality of the ground sta...Chiral defect-induced strategy is employed to synthesize zero-dimensional(0D)chiral Cs_(4)PbBr_(6) perovskite nanocrystals(NCs)with blue photoluminescence via a phase transition process.The chirality of the ground state of chiral Cs_(4)PbBr_(6) perovskite NCs is confirmed by circular dichroism(CD)spectra,which shows the characteristic mirrored CD signals,behaving as a pair of enantiomers.Meanwhile,the obvious circularly polarized luminescence(CPL)response indicates that the chiral Cs_(4)PbBr_(6) perovskite NCs are endowed with the chirality of the excited state.Furthermore,the UV–vis spectroscopy and electron paramagnetic resonance(EPR)data explicitly reveal that the CPL response originates from the chiral bromine vacancy(VBr).This work not only provides guidance to realize the CPL of 0D chiral perovskites but also gives insights into the structure–property relationship.展开更多
Bismuth halide hybrid perovskites have aroused intense interest in optoelectronic fields.However,developing novel bismuth halide hybrid perovskites to balance the hydrophobicity and electron transport ability is still...Bismuth halide hybrid perovskites have aroused intense interest in optoelectronic fields.However,developing novel bismuth halide hybrid perovskites to balance the hydrophobicity and electron transport ability is still challenging.Besides,the conventional temperature-lowering crystallization method usually causes high supersaturation and facilitates the formation of impurity phase and defect structures.Herein,we reported the synthesis of bulk zero-dimensional(0D)guanidinium bismuth iodide((Gua)_(3)Bi_(2)I_(9))single crystals via an antisolvent-assisted evaporation crystallization method at room temperature.The as-grown(Gua)_(3)Bi_(2)I_(9)single crystals have sizes of up to 5×5×0.6 mm^(3).Besides,they have shown to have distinct semiconductor properties,such as a direct bandgap of 2.08 eV,low density of defects and traps of 3.35×10^(10)cm^(−3)and obvious photoconductivity.Moreover,(Gua)_(3)Bi_(2)I_(9)exhibits a large bulk resistivity of 3.94×10^(11)Ωcm and strong X-ray attenuation coefficient,which satisfies the distinct attributes for X-ray detection.As a consequence,the assembled vertical Au/(Gua)^(3)Bi_(2)I_(9)single crystal/Au X-ray photoconductor achieves a sensitivity of 18.23μC Gyair^(−1)cm^(−2)at a bias voltage of 500 V.This study provides a new horizon for the design and synthesis of bismuth halide perovskites toward non-toxic X-ray detectors.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
Cyanide perovskites have demonstrated significant potential in the design of molecular ferroelastic,ferroelectric,and multiferroic materials.However,previous research has primarily focused on three-dimensional(3D)cyan...Cyanide perovskites have demonstrated significant potential in the design of molecular ferroelastic,ferroelectric,and multiferroic materials.However,previous research has primarily focused on three-dimensional(3D)cyanide perovskites,which are structurally constrained and exhibit limited diversity.In this study,we synthesized a new zero-dimensional(0D)cyanide perovskite ferroelastic material,(MA)_(3)[Fe(CN)_(6)](MA=CH_(3)NH_(3),methylamine),and conducted comprehensive characterization through differential scanning calorimetry(DSC),dielectric measurements,variable-temperature structural analysis,and polarized light microscopy.(MA)_(3)[Fe(CN)_(6)]undergoes an isomorphic phase transition with a spontaneous strain of 0.1063.The birefringence at 300 K and 330 K is 0.302@546 nm and 0.022@546 nm,respectively.The substantial birefringence change up to 0.28 mainly originates from the rotational motion of inorganic and organic components.This work establishes a new pathway for designing 0D cyanide perovskite materials.展开更多
Lead-free zero-dimensional(0D)hybrid antimony halide perovskites have emerged as promising materials for various optoelectronic and sensing applications,owing to their adjustable structural properties and non-toxic na...Lead-free zero-dimensional(0D)hybrid antimony halide perovskites have emerged as promising materials for various optoelectronic and sensing applications,owing to their adjustable structural properties and non-toxic nature.In this study,we explore the photophysical characteristics,structural robustness,and sensing capabilities of[FPPP]_(2)SbCl_(7)(FPPP=protonated 1-(2-fluorophenyl)piperazine).Employing a combination of experimental and theoretical approaches,we demonstrate its remarkable yellow light photoluminescence quantum yields(99.26%)and outstanding structural integrity.Moreover,investigations into the scintillation performance of[FPPP]_(2)SbCl_(7)single crystals reveal high X-ray light yields(46927 photons per MeV),a low detection limit(0.71μGy_(air)s^(−1))and high-quality X-ray imaging,making them promising candidates for X-ray detection applications.Furthermore,[FPPP]_(2_SbCl_(7)displays reversible fluorescence switching in response to nitrobenzene,showcasing its potential as a sensing platform for organic pollutants with outstanding repeatability and selectivity.Our findings not only deepen our comprehension of 0D hybrid antimony halides but also lay the groundwork for their utilization in diverse optoelectronic and sensing devices,opening new avenues for research in luminescent materials and detection applications.展开更多
Metal halide materials have demonstrated significant development prospects in the domain of highenergy radiation detection and imaging.When compared to lead-based metal halides,copper-based metal halide materials exhi...Metal halide materials have demonstrated significant development prospects in the domain of highenergy radiation detection and imaging.When compared to lead-based metal halides,copper-based metal halide materials exhibit advantages such as affordability,environmental compatibility,and outstanding luminescence properties.In this study,we synthesized a zero-dimensional cuprous-based organic-inorganic hybrid metal halide,[C_(11)H_(26)N]_(2)Cu_(2)I_(4).Through rational asymmetric design of cationic organic quaternary ammonium,this material can achieve cyan self-trapped exciton(STE)emission with a central wavelength of 490 nm.Due to the strong exciton binding and electron-phonon coupling effects,this material manifests a photoluminescence quantum yield(PLQY)close to unity(97.56%)at room temperature,a large Stokes shift(60606 cm^(-1)),and a short triplet lifetime(2.15μs).Furthermore,under soft X-ray excitation,the material attains a high light yield of 19900 photons per MeV,while exhibiting a detection limit as low as 0.524μGyair per s.Utilizing this material,flexible large-area X-ray imaging displays with an impressive image resolution of up to 5.47 lp mm^(-1) were fabricated.Consequently,the results reported here not only unveil the correlation between the high-performance luminescence properties and crystal structure of cuprous-based metal halides but also underscore the promising application prospects of the materials in the field of high-energy radiation detection.展开更多
文摘Zero mass flux jets, synthesized by acoustic actuators, have been used for the purpose of jet mixing enhancement and jet vectoring. Zero mass flux jets composed of entirely entrained fluid allow momentum transfer into the embedding flow. In the present experiments, miniature scale high aspect ratio actuator jets are placed along the long sides and near the exit plane of a primary two dimensional jet. In different modes, the primary jet can be vectored either towards or away from the actuator jets and the jet mixing is enhanced. The disturbance of the excitation frequency is developed while the unstable frequency of the primary jet is completely suppressed.
基金supported by the Development of airborne gravity gradiometer(No.2017YFC0601601)open subject of Key Laboratory of Petroleum Resources Research,Institute of Geology and Geophysics,Chinese Academy of Sciences(No.KLOR2018-8)
文摘This research proposes a novel three-dimensional gravity inversion based on sparse recovery in compress sensing. Zero norm is selected as the objective function, which is then iteratively solved by the approximate zero norm solution. The inversion approach mainly employs forward modeling; a depth weight function is introduced into the objective function of the zero norms. Sparse inversion results are obtained by the corresponding optimal mathematical method. To achieve the practical geophysical and geological significance of the results, penalty function is applied to constrain the density values. Results obtained by proposed provide clear boundary depth and density contrast distribution information. The method's accuracy, validity, and reliability are verified by comparing its results with those of synthetic models. To further explain its reliability, a practical gravity data is obtained for a region in Texas, USA is applied. Inversion results for this region are compared with those of previous studies, including a research of logging data in the same area. The depth of salt dome obtained by the inversion method is 4.2 km, which is in good agreement with the 4.4 km value from the logging data. From this, the practicality of the inversion method is also validated.
基金Project supported by the National Natural Science Foundation of China(Grant No.51972102).
文摘The toxicity and degradation of hybrid lead-halide perovskites hinder their extensive applications.It is thus of great importance to explore non-toxic alternative materials with excellent stability and optoelectronic property.We investigate the atomic structures and optoelectronic properties of non-toxic organic tin bromide perovskites(OTBP)with one/zerodimensional(1D/0D)structures by first-principles calculations.The calculated atomic structures show that the 1D/0D OTBPs are stable and the structure of inorganic octahedra in 0D is higher order than that in 1D.Moreover,the origination of exceptional purity emitting light in experiments is explained based on the calculated electronic structure.
基金supported by the Natural Science Foundation of Shandong Province(ZR2020MF128,ZR2021MB059)the Key projects of Natural Science Foundation of Shandong Province(ZR2020KB014)the Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3).
文摘Zero-dimensional(0D)lead-free all-inorganic metal halides have emerged as next-generation photoluminescent(PL)materials in recent years because of their extraordinary PL properties,non-toxicity,and high stability.Herein,a green,high stability,all-inorganic Rb_(2)CsBiCl_(6) single crystal with 0D structure was grown as a new PL material.Strikingly,using the antimony doping strategy,the broad yellow emission of Rb_(2)CsBiCl_(6) was significantly enhanced due to the enhanced absorption in the UV region,and the PL quantum yield was increased from 1%to 45%at room temperature.Furthermore,the fluorescent mechanism was revealed by the combination of optical characterizations and first-principles calculations.
基金supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Award No.DE-SC0021158We acknowledge Dr Douglas R.Powell for the assistance with the single-crystal X-ray diffraction measurements(instrument support from NSF grant CHE-1726630).
文摘This work explores the utilization of a photoactive organic cation for the preparation of R_(2)MCl_(4)(M=Zn,Cd;R=(E)-4-styrylpyridinium,C_(13)H_(12)N^(+)).The zero-dimensional crystal structures of R_(2)MCl_(4)contain isolated tetrahedral anions[MCl_(4)]_(2)-separated by the organic cations R+,leading to flat bands around the optical band gap.In R_(2)MCl_(4),the inorganic band gaps are sufficiently large to accommodate the organic molecular levels within,and therefore,the optical properties of R_(2)MCl_(4)are determined by the organic cation.Our combined optical spectroscopy and density functional theory(DFT)studies confirm the attribution of the bright green photoluminescence demonstrated by R_(2)MCl_(4)to the organic molecular emission.Importantly,the incorporation of the photoemissive organic cation R+into the hybrid framework in R_(2)MCl_(4)leads to a nearly two-fold enhancement of the light emission efficiency with the measured photoluminescence quantum yield(PLQY)values of 6.04%,10.40%and 11.21% for RCl,R_(2)ZnCl_(4)and R_(2)CdCl_(4),respectively.In addition,the crystal structure of the hybrid R_(2)MCl_(4)ensures a stabilized PL emission,preventing the occurrence of the harmful organic photodimerization,which is a notorious problem for this class of organic emitters.
基金supported by the National Natural Science Foundation of China(Grant No.22201195,22122106,22071158,and 21971171)Natural Science Foundation of Sichuan Province(2023NSFSC1066)the Fundamental Research Funds from Sichuan University(2021SCUNL101).
文摘Developing new birefringent materials with large optical anisotropy is extremely urgent due to the fantastic progress of laser science and technology.Here,two tin(Ⅱ)-based oxalates,K_(2)Sn(C_(2)O_(4))_(2)·H_(2)O and K_(2)Sn_(2)(C_(2)O_(4))_(2)F_(2)·H_(2)O,were successfully synthesized by simultaneously introducingπ-conjugated[C_(2)O_(4)]^(2)-groups and distorted Sn^(2+)-polyhedra with stereochemically active lone pairs.
基金supported by the National Natural Science Foundation of China(grant 21991141 and 22405243).
文摘Organic-inorganic hybrid ferroelectric materials have attracted much attention due to their structural tunability and functional versatility.While lone-pair stereochemical activity in elements such as Sb,Bi,and Pb has been widely used to design ferroelectrics,Ge^(2+)with a polar 4s^(2) lone-pair remains underexplored.Herein,a novel zero-dimensional hybrid ferroelectric[(CH_(3))4N]GeBr_(3)(1)was successfully synthesized by utilizing the stereochemically active lone pair of Ge^(2+).Compound 1 exhibits remarkable ferroelectric characteristics,including a large spontaneous polarization(P_(s)=4.80μC cm^(-2))and a low coercive field(E_(c)=5.20 kV cm^(-1)).Moreover,the experimental results demonstrate that 1 undergoes dual structural phase transitions at 236 K and 445 K.The low temperature phase transition at 236 K belongs to the mmmFmm2-type ferroelectric phase transition.Remarkably,1 undergoes a reconfiguration phase transition at 445 K,accompanied by the dimensional transformation from zero-dimensional to pseudo-threedimensional architecture and giant dielectric switching behaviour.This work establishes new structure-property correlations in hybrid ferroelectrics while uncovering emergent technological potential in smart switching devices.
基金supported by the National Natural Science Foundation of China (Grant No. 12174246 and 61875119)Science and Technology Commission of Shanghai Municipality (Grant No. 21010501300)The authors thank BL17B1 beamline of National Facility for Protein Science in Shanghai (NFPS) at Shanghai Synchrotron Radiation Facility and 2D-SMC (proposal No. 2020-1st-2D-024) of the Pohang Accelerator Laboratory for providing the beam time.
文摘Zero-dimensional(0D)metal halide clusters formed as isolated metal halide polyhedral structures show excellent optical properties and have great potential for various applications in optoelectronic devices.In this study,we reported a series of Rb_(8)CuB(III)_(3)Cl_(18)single crystals(SCs)constructed from Cu(I)and B(III)(B=In,Tb,etc.)containing lead-free bimetallic halide clusters.
基金funding from the National Natural Science Foundation of China(52073165).
文摘Zero-dimensional(0D)lead-free perovskites have garnered significant attention due to their unique optoelectronic properties and non-toxicity.However,the single response to stimuli in lead-free perovskites limits the versatility of multifunctional compounds.In this study,we abandoned the toxic bromic acid and utilized water as the reaction medium,to achieve an environmentally friendly green chemical route.We successfully prepared a zero-dimensional lead-free halide Cs_(2)In_(1−x)Sb_(x)Br_(5)(H_(2)O)perovskite with a fractal structure using an in situ solution crystallization method.Herein,we discovered that the recrystallization occurred beneath the smooth-grown rhombic crystal surface,forming fractal branched crystals.Interestingly,reversible luminescence color transitions from orange-red to yellow and return to the initial state were achieved in response to the individual stimuli of temperature and humidity.We found that H_(2)O molecules played a crucial role in the color tuning,enabling reversible“on–off”switching modes with rapid modulation rates.Moreover,the 0D lead-free halide perovskite Cs_(2)InBr_(5)(H_(2)O):Sb^(3+)also exhibited excellent temperature sensitivity,with the relative sensitivity(SR)reaching up to 9.39%K^(−1).This study provides valuable insights for the further development of halide perovskites in design and application fields,laying a foundation for the development of multifunctional smart materials and temperature sensing applications.
基金Financial support from the NSFC(21401077 and 21371078)the start-up fund of Jiaxing University is gratefully acknowledged.
文摘A series of chalcogenide compounds with various compositions,i.e.,octanuclear or tetranuclear Zn-S clusters,have been synthesised in a straighforward manner.Different fused-ring aromatic ligands were used as capping ligands and the corresponding zero-dimensional(0D)products were obtained.On the other hand,use of bridging ligands led to a family of one-dimensional(1D)coordination polymers,and an in situ ligand reaction has been observed in[Zn_(8)S(SC_(6)H_(5))_(13)L_(1)(H_(2)O)]·2H_(2)O(L=3-carboxypryidyl)due to the hydrolysis of the cyano group of 3-pyridinecarbonitrile.A very rare 1D helical-chain structure was observed in[Zn_(4)(SC_(6)H_(5))_(8)L_(1)](L=4,4’-bipyridyl),providing evidence of the character of bridging organic ligands in the corresponding crystalline materials.First-principles calculations on[Zn_(4)(SC_(6)H_(5))_(8)L_(1)](L=4,4’-bipyridyl)further revealed that the two cluster units could rotate freely about the C-C single bond over a broad range,eventually leading to the formation of a one-dimensional helical structure.
基金support from the National Nature Science Foundation of China(22171105)Shandong Provincial Natural Science Foundation(ZR2022YQ14 and ZR2021MB001)the Special Foundation of Taishan Scholar Project.
文摘Zero-dimensional(0D)cuprous organic–inorganic hybrid halides have emerged as a new kind of scintillator due to their high light yield and adjustable emission properties in the whole visible spectral range.However,their practical application in the radiation industry is seriously hindered by the instability of CuⅠ ions under humid atmospheres and oxidizing environments.Herein,we designed a new Cu(Ⅰ)-based halide of[CEOMTPP]_(2)Cu_(4)Br_(6)(CEOMTPP=ethoxycarbonylmethyl(triphenyl)phosphonium cation)containing a discrete[Cu_(4)Br_(6)]_(2)−nanocluster,which displays strong broadband yellow light emission with near-unity photoluminescence quantum yield(PLQY)and large Stokes shift of 206 nm.Remarkably,[CEOMTPP]_(2)Cu_(4)Br_(6) shows ultra-high anti-water and anti-oxidation stability with steady emitting performance in water for over one year and in an acid–base aqueous solution for one day.Benefiting from the near-unity PLQY,large Stokes shift and negligible self-absorption,[CEOMTPP]_(2)Cu_(4)Br_(6) exhibits excellent scintillation properties with a high light yield of 69500 phonon per meV and low detection limit of 113.0 nGy s^(−1).Furthermore,a high spatial resolution of 14.5 lp mm^(−1) is achieved in X-ray imaging based on a[CEOMTPP]_(2)Cu_(4)Br_(6)@EVA composite-assembled scintillation screen,demonstrating its potential application in medical photography.This research provides a fundamental structural engineering strategy to design highly efficient and stable low-dimensional Cu(Ⅰ)halides for X-ray radiation application.
基金supported by the Natural Science Foundation of Shanxi Province(No.20210302124054)the National Natural Science Foundation of China(No.21871167)+2 种基金the Science and Technology Innovation Project of Colleges and Universities in Shanxi Province(No.2021L262)the 1331 Project of Shanxi Province and the Postgraduate Innovation Project of Shanxi Normal University(No.2021XSY040)funded by RFBR according to the research project No.19-52-80003.
文摘Low-dimensional metal halides have emerged as promising platforms for the development of new-generation phosphor-converted light emitting diodes(pc-LEDs),in which zero-dimensional(0D)hybrids with lone-pair ns_(2)states,in particular,show unprecedented competitiveness owing to their fascinating photoluminescence(PL)properties.
基金supported by the National Natural Science Foundation of China Natural(no.21771083).
文摘Chiral defect-induced strategy is employed to synthesize zero-dimensional(0D)chiral Cs_(4)PbBr_(6) perovskite nanocrystals(NCs)with blue photoluminescence via a phase transition process.The chirality of the ground state of chiral Cs_(4)PbBr_(6) perovskite NCs is confirmed by circular dichroism(CD)spectra,which shows the characteristic mirrored CD signals,behaving as a pair of enantiomers.Meanwhile,the obvious circularly polarized luminescence(CPL)response indicates that the chiral Cs_(4)PbBr_(6) perovskite NCs are endowed with the chirality of the excited state.Furthermore,the UV–vis spectroscopy and electron paramagnetic resonance(EPR)data explicitly reveal that the CPL response originates from the chiral bromine vacancy(VBr).This work not only provides guidance to realize the CPL of 0D chiral perovskites but also gives insights into the structure–property relationship.
基金supported by the National Key R&D Program of China(grant no.2019YFB1503500)National Natural Science Foundation of China(grant no.21805075,11774082,11975093)+1 种基金the Natural Science Foundation of Hubei Province(Grant no.2019CFA006)the Program for Science and Technology Innovation Team in Colleges of Hubei Province(grant no.T201901).
文摘Bismuth halide hybrid perovskites have aroused intense interest in optoelectronic fields.However,developing novel bismuth halide hybrid perovskites to balance the hydrophobicity and electron transport ability is still challenging.Besides,the conventional temperature-lowering crystallization method usually causes high supersaturation and facilitates the formation of impurity phase and defect structures.Herein,we reported the synthesis of bulk zero-dimensional(0D)guanidinium bismuth iodide((Gua)_(3)Bi_(2)I_(9))single crystals via an antisolvent-assisted evaporation crystallization method at room temperature.The as-grown(Gua)_(3)Bi_(2)I_(9)single crystals have sizes of up to 5×5×0.6 mm^(3).Besides,they have shown to have distinct semiconductor properties,such as a direct bandgap of 2.08 eV,low density of defects and traps of 3.35×10^(10)cm^(−3)and obvious photoconductivity.Moreover,(Gua)_(3)Bi_(2)I_(9)exhibits a large bulk resistivity of 3.94×10^(11)Ωcm and strong X-ray attenuation coefficient,which satisfies the distinct attributes for X-ray detection.As a consequence,the assembled vertical Au/(Gua)^(3)Bi_(2)I_(9)single crystal/Au X-ray photoconductor achieves a sensitivity of 18.23μC Gyair^(−1)cm^(−2)at a bias voltage of 500 V.This study provides a new horizon for the design and synthesis of bismuth halide perovskites toward non-toxic X-ray detectors.
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 Key R&D Program of China(2024YFA1509300)the National Natural Science Foundation of China(22201120)Gan Po Juncai Support Program−the Academic and Technical Leader Training Program in Major Disciplines(20243BCE51149).
文摘Cyanide perovskites have demonstrated significant potential in the design of molecular ferroelastic,ferroelectric,and multiferroic materials.However,previous research has primarily focused on three-dimensional(3D)cyanide perovskites,which are structurally constrained and exhibit limited diversity.In this study,we synthesized a new zero-dimensional(0D)cyanide perovskite ferroelastic material,(MA)_(3)[Fe(CN)_(6)](MA=CH_(3)NH_(3),methylamine),and conducted comprehensive characterization through differential scanning calorimetry(DSC),dielectric measurements,variable-temperature structural analysis,and polarized light microscopy.(MA)_(3)[Fe(CN)_(6)]undergoes an isomorphic phase transition with a spontaneous strain of 0.1063.The birefringence at 300 K and 330 K is 0.302@546 nm and 0.022@546 nm,respectively.The substantial birefringence change up to 0.28 mainly originates from the rotational motion of inorganic and organic components.This work establishes a new pathway for designing 0D cyanide perovskite materials.
基金the National Natural Science Foundation of China(No.22201099 and 22101282)the Shandong Provincial Natural Science Foundation(ZR2021QB204)+1 种基金the Jining University 2019,2020“100 Outstanding Talents”support program cultivation project(2020ZYRC02)supported by the University Feature Laboratory for Energy Conversion and Nanocatalysis of Shandong Province.
文摘Lead-free zero-dimensional(0D)hybrid antimony halide perovskites have emerged as promising materials for various optoelectronic and sensing applications,owing to their adjustable structural properties and non-toxic nature.In this study,we explore the photophysical characteristics,structural robustness,and sensing capabilities of[FPPP]_(2)SbCl_(7)(FPPP=protonated 1-(2-fluorophenyl)piperazine).Employing a combination of experimental and theoretical approaches,we demonstrate its remarkable yellow light photoluminescence quantum yields(99.26%)and outstanding structural integrity.Moreover,investigations into the scintillation performance of[FPPP]_(2)SbCl_(7)single crystals reveal high X-ray light yields(46927 photons per MeV),a low detection limit(0.71μGy_(air)s^(−1))and high-quality X-ray imaging,making them promising candidates for X-ray detection applications.Furthermore,[FPPP]_(2_SbCl_(7)displays reversible fluorescence switching in response to nitrobenzene,showcasing its potential as a sensing platform for organic pollutants with outstanding repeatability and selectivity.Our findings not only deepen our comprehension of 0D hybrid antimony halides but also lay the groundwork for their utilization in diverse optoelectronic and sensing devices,opening new avenues for research in luminescent materials and detection applications.
基金supported by the National Natural Science Foundation of China(52072355,62304213,and 52103241)the Liu Zugang Expert Workstation of Yunnan Province.
文摘Metal halide materials have demonstrated significant development prospects in the domain of highenergy radiation detection and imaging.When compared to lead-based metal halides,copper-based metal halide materials exhibit advantages such as affordability,environmental compatibility,and outstanding luminescence properties.In this study,we synthesized a zero-dimensional cuprous-based organic-inorganic hybrid metal halide,[C_(11)H_(26)N]_(2)Cu_(2)I_(4).Through rational asymmetric design of cationic organic quaternary ammonium,this material can achieve cyan self-trapped exciton(STE)emission with a central wavelength of 490 nm.Due to the strong exciton binding and electron-phonon coupling effects,this material manifests a photoluminescence quantum yield(PLQY)close to unity(97.56%)at room temperature,a large Stokes shift(60606 cm^(-1)),and a short triplet lifetime(2.15μs).Furthermore,under soft X-ray excitation,the material attains a high light yield of 19900 photons per MeV,while exhibiting a detection limit as low as 0.524μGyair per s.Utilizing this material,flexible large-area X-ray imaging displays with an impressive image resolution of up to 5.47 lp mm^(-1) were fabricated.Consequently,the results reported here not only unveil the correlation between the high-performance luminescence properties and crystal structure of cuprous-based metal halides but also underscore the promising application prospects of the materials in the field of high-energy radiation detection.
