In this paper, we demonstrate an alternative approach to fabricating an electrically tunable holographic polymer tem- plated blue phase liquid crystal grating. This grating is obtained by preforming a polymer template...In this paper, we demonstrate an alternative approach to fabricating an electrically tunable holographic polymer tem- plated blue phase liquid crystal grating. This grating is obtained by preforming a polymer template comprised of periodic fringes, and then refilling it with a blue phase liquid crystal. Compared with conventional holographic polymer dispersed liquid crystal gratings, our grating can remarkably reduce its switching voltage from 200 V to 43 V while maintaining a sub-millisecond response time. The holographic polymer templated blue phase liquid crystal （HPTBPLC） grating is free from electrode patterning, thus leading to a lower cost and more flexible applications.展开更多
In this paper,we investigate the bichromatic coherent random lasing actions from the dye-doped polymer stabilized blue phase liquid crystals.Two groups of lasing peaks,of which the full widith at half maximum is about...In this paper,we investigate the bichromatic coherent random lasing actions from the dye-doped polymer stabilized blue phase liquid crystals.Two groups of lasing peaks,of which the full widith at half maximum is about 0.3 nm,are clearly observed.The shorter-and longer-wavelength modes are associated with the excitation of the single laser dye（DCM） monomers and dimers respectively.The experimental results show that the competition between the two groups of the lasing peaks can be controlled by varying the polarization of the pump light.When the polarization of the pump light is rotated from 0？to 90？,the intensity of the shorter-wavelength lasing peak group reduces while the intensity of the longer-wavelength lasing peak group increases.In addition,a red shift of the longer-wavelength modes is also observed and the physical mechanisms behind the red-shift phenomenon are discussed.展开更多
The Cu_2MoS_4 nanoparticles were prepared using a relatively simple and convenient solid-phase process, which was applied for the first time. The crystalline structure, morphology, and optical properties of Cu_2MoS_4 ...The Cu_2MoS_4 nanoparticles were prepared using a relatively simple and convenient solid-phase process, which was applied for the first time. The crystalline structure, morphology, and optical properties of Cu_2MoS_4 nanoparticles were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and UV-vis spectrophotometry. Cu_2MoS_4 nanoparticles having a band gap of 1.66 eV exhibits good photocatalytic activity in the degradation of methylene blue, which indicates that this simple process may be critical to facilitate the cheap production of photocatalysts.展开更多
The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the ...The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the finite-difference timedomain method,which is used to directly solve Maxwell＇s equations,can consider the lateral variation of the refractive index and obtain an accurate convergence effect.The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage.The finitedifference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change.展开更多
Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition.The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-colo...Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition.The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-color emissions at the wavelength peak values of 437 nm and 620 nm at the excitation of 350 nm.The two emission bands are coincident with the absorption spectrum for photosynthesis of plants.An obvious enhancement effect has been observed upon addition of Dy3+ with amount of 0.03 mol%,in which the ...展开更多
The blue phase,which emerges between cholesteric and isotropic phases within a threedimensional periodical superstructure,is of great significance in display and photonic applications.The crystalline orientation plays...The blue phase,which emerges between cholesteric and isotropic phases within a threedimensional periodical superstructure,is of great significance in display and photonic applications.The crystalline orientation plays an important role in the macroscopic performance of the blue phase,where the single crystal shows higher uniformity over the polydomain and monodomain,resulting in higher Bragg reflection intensity,lower hysteresis,and lower driving voltage.However,currently reported methods of forming a single-crystal blue phase based on thermal controlling or e-beam lithography are quite time-consuming or expensive for large-scale fabrication,especially in the centimeter range,thus hindering the broad practical applications of single-crystal blue-phase-based photonic devices.Herein,a strategy to fabricate a large scale single crystalline blue-phase domain using holography lithography is proposed.Defect-free single-crystal domains both in blue phase I and blue phase II with a desired orientation of over 1 cm^(2) are fabricated based on a nanopatterned grating with periodic homeotropic and degenerate parallel anchoring,with colors from red and green to blue.This holography lithography-assisted strategy for fabrication of a large-scale singlecrystal blue phase provides a time-saving and low-cost method for a defect-free single crystalline structure,leading to broad applications in liquid crystal displays,laser devices,adaptive optics elements,and electrooptical devices.展开更多
A transflective polymer-stabilized blue-phase liquid crystal display（BP-LCD） with a non-uniform etching substrate is proposed.In-plane switching（IPS） electrodes on the bottom substrate are put on the different gap...A transflective polymer-stabilized blue-phase liquid crystal display（BP-LCD） with a non-uniform etching substrate is proposed.In-plane switching（IPS） electrodes on the bottom substrate are put on the different gaps,and the bottom substrate between the electrodes is etched into different depths in transmissive（T） and reflective（R） regions.This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves.This transflective display has high optical efficiency,a wide viewing angle,and low operating voltage（approximately 6 V）.展开更多
The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study cor...The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study correlates the performance of the nickel hexacyanoferrate to the dynamics of H_(2)O in the electrolyte and the associated phase stability of the electrode.It demonstrates severe Ni dissolution in conventional diluted aqueous electrolyte(1 M ZnSO^(4)or 1 M Zn(TFSI)^(2)),leading to structure collapse with the formation of an electrochemical inert phase.This is regarded as the descriptor for the fast decay of nickel hexacyanoferrate in diluted aqueous electrolyte.However,a well-preserved open framework for zinc storage was obtained in concentrated aqueous electrolyte(1 M Zn(TFSI)_(2)+21 M LiTFSI)—the H_(2)O activity is highly suppressed by extensive coordination—thus,reversible capacity of 60.2 m Ah g^(-1)over 1600 cycles could be delivered.展开更多
Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications,such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes.Aside from ...Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications,such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes.Aside from exploring their abnormal physical behavior,fabrication of such structures also presents a great challenge to this area,owing to the subtle and sensitive interactions among neighboring layers.Here we show by molecular dynamics simulations that narrow blue phosphorene nanoribbons can be encapsulated into carbon nanotubes driven by van der Waals interactions and form one-dimensional heterostructures.It shows that by varying carbon nanotube diameters and nanoribbon width,the nanoribbons can either retain their original straight structures or twist into tubular structures.Wrapping phases are also observed for large-sized blue phosphorus.It is found that the underlying mechanism originates from the competition between van der Waals energy and bending energy induced by tube curvature.A phase diagram of the resultant 1D structure is thus obtained based on a simple analysis of energetics.The results are expected to stimulate further experimental efforts in fabricating one-dimensional van der Waals heterostructues with desired functionality.展开更多
In this paper the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of Bromophenol Blue using the Z-scan technique with a continuous wave laser beam at wavelengths 488 ...In this paper the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of Bromophenol Blue using the Z-scan technique with a continuous wave laser beam at wavelengths 488 nm and 514 nm are presented. It was observed that the material exhibited reverse saturation absorption and self defocusing behavior. It was found that the increase in solution concentration resulted in linear increase of the nonlinear refractive index. A pump and probe technique was used to obtain the absorption spectrum of triplet state. Furthermore the nonlinear absorption effect was used to demonstrate all optical switching.展开更多
In this work we investigated the geometric phases of a qubit-oscillator system beyond the conventional rotating- wave approximation. We find that in the limiting of weak coupling the results coincide with that obtaine...In this work we investigated the geometric phases of a qubit-oscillator system beyond the conventional rotating- wave approximation. We find that in the limiting of weak coupling the results coincide with that obtained under rotating-wave approximation while there exists an increasing difference with the increase of coupling constant. It was shown that the geometric phase is symmetric with respect to the sign of the detuning of the quantized field from the one-photon resonance under the conventional rotating-wave approximation while a red-blue detuning asymmetry occurs beyond the conventional rotating-wave approximation.展开更多
Deep-blue perovskite light-emitting diodes(PeLEDs)based on reduced-dimensional perovskites(RDPs)still face a few challenges including severe trap-assisted nonradiative recombination,sluggish exciton transfer,and undes...Deep-blue perovskite light-emitting diodes(PeLEDs)based on reduced-dimensional perovskites(RDPs)still face a few challenges including severe trap-assisted nonradiative recombination,sluggish exciton transfer,and undesirable bathochromic shift of the electroluminescence spectra,impeding the realization of high-performance PeLEDs.Herein,an in situ chlorination(isCl)post-treatment strategy was employed to regulate phase reconstruction and renovate multiple defects of RDPs,leading to superior carrier cooling of 0.88 ps,extraordinary exciton binding energy of 122.53 meV,and higher photoluminescence quantum yield of 60.9%for RDP films with deep-blue emission at 450 nm.The phase regulation is accomplished via fluorine-derived hydrogen bonds that suppress the formation of small-n phases.Multiple defects,including halide vacancies(shallow-state defects)and lead-chloride antisite defects(deepstate defects),are renovated via C=O coordination and hydroxy-group-derived hydrogen bonds.Consequently,deepblue PeLEDs with a record maximum external quantum efficiency of 6.17%and stable electroluminescence at 454 nm were demonstrated,representing the best-performing deep-blue PeLEDs.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2013CB328804)the National Natural Science Foundation of China(Grant No.61307028)+1 种基金the Funds from the Science and Technology Commission of Shanghai Municipality(Grant Nos.11JC1405300,13ZR1420000,and14ZR1422300)the Fundamental Research Funds for the Central Universities,China(Grant No.XDJK 2011C047)
文摘In this paper, we demonstrate an alternative approach to fabricating an electrically tunable holographic polymer tem- plated blue phase liquid crystal grating. This grating is obtained by preforming a polymer template comprised of periodic fringes, and then refilling it with a blue phase liquid crystal. Compared with conventional holographic polymer dispersed liquid crystal gratings, our grating can remarkably reduce its switching voltage from 200 V to 43 V while maintaining a sub-millisecond response time. The holographic polymer templated blue phase liquid crystal （HPTBPLC） grating is free from electrode patterning, thus leading to a lower cost and more flexible applications.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474021 and 51333001)the Key Program for International S&T Cooperation Projects of China(Grant No.2013DFB50340)+1 种基金the Issues of Priority Development Areas of the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120001130005)the Key(Key Grant)Project of Chinese Ministry of Education(Grant No.313002)
文摘In this paper,we investigate the bichromatic coherent random lasing actions from the dye-doped polymer stabilized blue phase liquid crystals.Two groups of lasing peaks,of which the full widith at half maximum is about 0.3 nm,are clearly observed.The shorter-and longer-wavelength modes are associated with the excitation of the single laser dye（DCM） monomers and dimers respectively.The experimental results show that the competition between the two groups of the lasing peaks can be controlled by varying the polarization of the pump light.When the polarization of the pump light is rotated from 0？to 90？,the intensity of the shorter-wavelength lasing peak group reduces while the intensity of the longer-wavelength lasing peak group increases.In addition,a red shift of the longer-wavelength modes is also observed and the physical mechanisms behind the red-shift phenomenon are discussed.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. FRF-BD-15-004A)
文摘The Cu_2MoS_4 nanoparticles were prepared using a relatively simple and convenient solid-phase process, which was applied for the first time. The crystalline structure, morphology, and optical properties of Cu_2MoS_4 nanoparticles were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and UV-vis spectrophotometry. Cu_2MoS_4 nanoparticles having a band gap of 1.66 eV exhibits good photocatalytic activity in the degradation of methylene blue, which indicates that this simple process may be critical to facilitate the cheap production of photocatalysts.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304074,61475042,and 11274088)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2015202320 and GCC2014048)the Key Subject Construction Project of Hebei Province University,China
文摘The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the finite-difference timedomain method,which is used to directly solve Maxwell＇s equations,can consider the lateral variation of the refractive index and obtain an accurate convergence effect.The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage.The finitedifference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change.
基金supported by National Natural Science Foundation of China (Grant No 50872091)the Natural Science Foundation of Tianjin,China(06YFJMJC02300,06TXTJJC14602)
文摘Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition.The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-color emissions at the wavelength peak values of 437 nm and 620 nm at the excitation of 350 nm.The two emission bands are coincident with the absorption spectrum for photosynthesis of plants.An obvious enhancement effect has been observed upon addition of Dy3+ with amount of 0.03 mol%,in which the ...
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.61875081 and 62175098)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021B1515020097).
文摘The blue phase,which emerges between cholesteric and isotropic phases within a threedimensional periodical superstructure,is of great significance in display and photonic applications.The crystalline orientation plays an important role in the macroscopic performance of the blue phase,where the single crystal shows higher uniformity over the polydomain and monodomain,resulting in higher Bragg reflection intensity,lower hysteresis,and lower driving voltage.However,currently reported methods of forming a single-crystal blue phase based on thermal controlling or e-beam lithography are quite time-consuming or expensive for large-scale fabrication,especially in the centimeter range,thus hindering the broad practical applications of single-crystal blue-phase-based photonic devices.Herein,a strategy to fabricate a large scale single crystalline blue-phase domain using holography lithography is proposed.Defect-free single-crystal domains both in blue phase I and blue phase II with a desired orientation of over 1 cm^(2) are fabricated based on a nanopatterned grating with periodic homeotropic and degenerate parallel anchoring,with colors from red and green to blue.This holography lithography-assisted strategy for fabrication of a large-scale singlecrystal blue phase provides a time-saving and low-cost method for a defect-free single crystalline structure,leading to broad applications in liquid crystal displays,laser devices,adaptive optics elements,and electrooptical devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61535007 and 61320106015)the National Basic Research Program of China(Grant No.2013CB328802)
文摘A transflective polymer-stabilized blue-phase liquid crystal display（BP-LCD） with a non-uniform etching substrate is proposed.In-plane switching（IPS） electrodes on the bottom substrate are put on the different gaps,and the bottom substrate between the electrodes is etched into different depths in transmissive（T） and reflective（R） regions.This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves.This transflective display has high optical efficiency,a wide viewing angle,and low operating voltage（approximately 6 V）.
基金financial support provided by National Key Research and Development Program(No.2019YFA0210600)the National Natural Science Foundation of China(No.21905085+2 种基金No.51972107)the State Grid Shanghai Municipal Electric Power Company(No.B30970190001)the Innovative Research Groups of Hunan Province(No.2019JJ10001)
文摘The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study correlates the performance of the nickel hexacyanoferrate to the dynamics of H_(2)O in the electrolyte and the associated phase stability of the electrode.It demonstrates severe Ni dissolution in conventional diluted aqueous electrolyte(1 M ZnSO^(4)or 1 M Zn(TFSI)^(2)),leading to structure collapse with the formation of an electrochemical inert phase.This is regarded as the descriptor for the fast decay of nickel hexacyanoferrate in diluted aqueous electrolyte.However,a well-preserved open framework for zinc storage was obtained in concentrated aqueous electrolyte(1 M Zn(TFSI)_(2)+21 M LiTFSI)—the H_(2)O activity is highly suppressed by extensive coordination—thus,reversible capacity of 60.2 m Ah g^(-1)over 1600 cycles could be delivered.
基金supported by the National Natural Science Foundation of China via Grant Nos.12072134 and 22073048Jiangsu Province NSF via Grant No.BK20191426supported by Jiangsu Province Research Innovation Program Project for University Postgraduates (#KYCX21_3325).
文摘Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications,such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes.Aside from exploring their abnormal physical behavior,fabrication of such structures also presents a great challenge to this area,owing to the subtle and sensitive interactions among neighboring layers.Here we show by molecular dynamics simulations that narrow blue phosphorene nanoribbons can be encapsulated into carbon nanotubes driven by van der Waals interactions and form one-dimensional heterostructures.It shows that by varying carbon nanotube diameters and nanoribbon width,the nanoribbons can either retain their original straight structures or twist into tubular structures.Wrapping phases are also observed for large-sized blue phosphorus.It is found that the underlying mechanism originates from the competition between van der Waals energy and bending energy induced by tube curvature.A phase diagram of the resultant 1D structure is thus obtained based on a simple analysis of energetics.The results are expected to stimulate further experimental efforts in fabricating one-dimensional van der Waals heterostructues with desired functionality.
文摘In this paper the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of Bromophenol Blue using the Z-scan technique with a continuous wave laser beam at wavelengths 488 nm and 514 nm are presented. It was observed that the material exhibited reverse saturation absorption and self defocusing behavior. It was found that the increase in solution concentration resulted in linear increase of the nonlinear refractive index. A pump and probe technique was used to obtain the absorption spectrum of triplet state. Furthermore the nonlinear absorption effect was used to demonstrate all optical switching.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11075099, 11047167, and 11105087)the Programme of State Key Laboratory of Quantum Optics and Quantum Optics Devices (Grant No. KF201002)+1 种基金the National Fundamental Fund of Personnel Training (Grant No. J1103210)the Youth Science Foundation of Shanxi Province of China (Grant No. 2010021003-2)
文摘In this work we investigated the geometric phases of a qubit-oscillator system beyond the conventional rotating- wave approximation. We find that in the limiting of weak coupling the results coincide with that obtained under rotating-wave approximation while there exists an increasing difference with the increase of coupling constant. It was shown that the geometric phase is symmetric with respect to the sign of the detuning of the quantized field from the one-photon resonance under the conventional rotating-wave approximation while a red-blue detuning asymmetry occurs beyond the conventional rotating-wave approximation.
基金supported by the following grants:the National Youth Science Funds of China(Grant No.52302172)the Key Program of the National Natural Science Foundation of China(Grant No.52032004)+2 种基金the National Natural Science Foundation of China(Grant No.21902135,92056204)Y.B.Zhao would like to acknowledge the support of the National Natural Science Foundation of China(Grant No.61905206,12364054,and 11804294)Besides,we extend gratitude to the Theoretical and Computational Chemistry Team from Shiyanjia Lab for providing invaluable assistance(www.shiyanjia.com).
文摘Deep-blue perovskite light-emitting diodes(PeLEDs)based on reduced-dimensional perovskites(RDPs)still face a few challenges including severe trap-assisted nonradiative recombination,sluggish exciton transfer,and undesirable bathochromic shift of the electroluminescence spectra,impeding the realization of high-performance PeLEDs.Herein,an in situ chlorination(isCl)post-treatment strategy was employed to regulate phase reconstruction and renovate multiple defects of RDPs,leading to superior carrier cooling of 0.88 ps,extraordinary exciton binding energy of 122.53 meV,and higher photoluminescence quantum yield of 60.9%for RDP films with deep-blue emission at 450 nm.The phase regulation is accomplished via fluorine-derived hydrogen bonds that suppress the formation of small-n phases.Multiple defects,including halide vacancies(shallow-state defects)and lead-chloride antisite defects(deepstate defects),are renovated via C=O coordination and hydroxy-group-derived hydrogen bonds.Consequently,deepblue PeLEDs with a record maximum external quantum efficiency of 6.17%and stable electroluminescence at 454 nm were demonstrated,representing the best-performing deep-blue PeLEDs.
