In recent years,electromagnetic wave(EMW)absorption has been extensively investigated for solving EMW radiation and pollution.The metal-organic frameworks(MOFs)have attracted attention due to their low density and uni...In recent years,electromagnetic wave(EMW)absorption has been extensively investigated for solving EMW radiation and pollution.The metal-organic frameworks(MOFs)have attracted attention due to their low density and unique structure,which can meet the requirements of strong reflection loss(RL)and wide absorption bandwidth of EMW absorption materials.In this manuscript,indium nanoparticles/porous carbon(In/C)nanorods composites were prepared via the pyrolysis of nanorods-like In-MOFs at a low temperature of450°C.Indium nanoparticles are evenly attached and embedded on porous carbon.Low electrical conductivity of In/C nanorods is unfavorable to EMW absorption performance,which is due to the low temperature carbonization.Thus,graphene(Gr)nanosheets with high electrical conductivity are introduced to adjust electromagnetic parameters of In/C nanorods for enhancing EMW absorption.The minimum RL of the In/C-Gr-4 composite is up to-43.7 dB with a thin thickness of 1.30 mm.In addition,when the thickness is further reduced to 1.14 mm,the minimum RL of-39.3 dB at 16.1 GHz and effective absorption bandwidth of 3.7 GHz(from 14.3 to 18.0 GHz)can be achieved.This work indicates that In/C-Gr composites show excellent EMW absorption performance.展开更多
Surface plasmon resonance induced tunable polarization filters based on nanoscale gold film-coated photonic crystal fibers were proposed and analyzed. The characteristics of the polarization filter were calculated by ...Surface plasmon resonance induced tunable polarization filters based on nanoscale gold film-coated photonic crystal fibers were proposed and analyzed. The characteristics of the polarization filter were calculated by finite element method (FEM). The gold film was selectively coated on the inner wall of one cladding air hole which was located near the fiber core along the y-axis direction. When the phase of core fundamental mode and surface plasmon polaritons (SPPs) mode matches, the two modes couple with each other intensely. Numerical results show that the resonance wavelength and strength vary with fiber structural parameters and the index of the infilling liquid. The fiber parameters were optimized to achieve specific functions. Under the optimal structure, we realized a dual channel filter at the communication wavelength of 1.31 μm and 1.55 μm fory polarization direction and x polarization direction. Then a single channel polarized filter at the communication wavelength of 1.55 μm is also achieved by adjusting the refractive index of the infilling liquid. The proposed polarization filters realized dual channel filtering and single channel filtering simultaneously under the same structure for the first time to the best of our knowledge.展开更多
Double-crystal x-ray diffraction has been used to measure the rocking curve of Ta/Al multilayers.The diffraction profiles of the multilayers are different.Besides the normal profile,two kinds of distorted profiles hav...Double-crystal x-ray diffraction has been used to measure the rocking curve of Ta/Al multilayers.The diffraction profiles of the multilayers are different.Besides the normal profile,two kinds of distorted profiles have been found.The simulations show that the deformed profiles of the peaks are caused by the imperfect periodicity(e.g.systematic period deviation and coexistence of two slightly different periods)in the multilayers.展开更多
Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals hete...Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals heterostructures by a two-step chemical vapor deposition(CVD)method.After the growth of In_(2)Se_(3) at elevated temperatures,high densities of In_(2)Se_(3)/WS_(2) heterostructure bubbles with monolayer to multilayerβ-In_(2)Se_(3) crystals atop are observed.Fluorescence of the resultantβ-In_(2)Se_(3)/WS_(2) heterostructure is greatly enhanced in intensity upon the formation of bubbles,which are evidenced by the Newton’s rings in optical image owing to constructive and destructive interference.In photoluminescence(PL)mapping images of monolayerβ-In_(2)Se_(3)/monolayer WS2 heterobilayer bubble,significant oscillatory behavior of emission intensity is demonstrated due to constructive and destructive interference.However,oscillatory behaviors of peak position are also observed and come from a local heating effect induced by an excitation laser beam.The oscillatory mechanism of PL is further verified by changing the exterior pressure of bubbles placed in a home-made vacuum chamber.In addition,redshifted in peak position and broadening in peak width are observed due to strain effect during decreasing the exterior pressure of bubbles.展开更多
本文利用微波辅助水热法在碳布上快速合成了CoP纳米线阵列(CoP/CC)双功能电极材料,可用于析氢反应(HER)和超级电容器的电极.CoP/CC用于HER时展现了优越的电化学性能,其塔菲尔斜率为56 mV/dec.当电流密度为10 mA cm^(-2)时,其电位低至68 ...本文利用微波辅助水热法在碳布上快速合成了CoP纳米线阵列(CoP/CC)双功能电极材料,可用于析氢反应(HER)和超级电容器的电极.CoP/CC用于HER时展现了优越的电化学性能,其塔菲尔斜率为56 mV/dec.当电流密度为10 mA cm^(-2)时,其电位低至68 mV.值得注意的是,CoP/CC也可用于超级电容器的电极.在扫描速率为5 mV s^(-1)时,其比电容高达674 F g^(-1).同时具有高的循环稳定性,在循环10000次后,比电容仍然可以维持在初始值的86%.本文结果表明,CoP/CC可以作为HER和超级电容器电极的有力候选者.展开更多
The three-dimensional nanoflower-like β-In2S3 composited with carbon nanotubes {CNTs) has been synthesized by a single mode micro- wave-assisted hydrothermal technique. The In2S3 and CNTs nanocomposites (In2S3@CNTs...The three-dimensional nanoflower-like β-In2S3 composited with carbon nanotubes {CNTs) has been synthesized by a single mode micro- wave-assisted hydrothermal technique. The In2S3 and CNTs nanocomposites (In2S3@CNTs) were investigated as the anode materials of lithium batteries (LIBs) and the electromagnetic wave absorption materials. For LIBs applications, the In2S3@CNTs nanocomposite exhibited excellent cycling stability with a high reversible charge capacity of 575 mA·h·g-1 after 300 cycles at 0.S A·g^-1, In addition, the In2S3@CNTs used as electromagnetic wave absorber displayed a maximum reflection loss of-42.75 dB at 11.96 GHz with a thickness of 1.55 ram.展开更多
Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2....Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.展开更多
基金supported by the National Natural Science Foundation of China(No.52071280)the Natural Science Foundation of Hebei Province,China(No.E2020203151)+2 种基金the Research Program of the College Science&Technology of Hebei Province,China(No.ZD2020121)the Cultivation Project for Basic Research and Innovation of Yanshan University(No.2021LGZD016)the Innovation Capability Improvement Project of Hebei province(No.22567605H)。
文摘In recent years,electromagnetic wave(EMW)absorption has been extensively investigated for solving EMW radiation and pollution.The metal-organic frameworks(MOFs)have attracted attention due to their low density and unique structure,which can meet the requirements of strong reflection loss(RL)and wide absorption bandwidth of EMW absorption materials.In this manuscript,indium nanoparticles/porous carbon(In/C)nanorods composites were prepared via the pyrolysis of nanorods-like In-MOFs at a low temperature of450°C.Indium nanoparticles are evenly attached and embedded on porous carbon.Low electrical conductivity of In/C nanorods is unfavorable to EMW absorption performance,which is due to the low temperature carbonization.Thus,graphene(Gr)nanosheets with high electrical conductivity are introduced to adjust electromagnetic parameters of In/C nanorods for enhancing EMW absorption.The minimum RL of the In/C-Gr-4 composite is up to-43.7 dB with a thin thickness of 1.30 mm.In addition,when the thickness is further reduced to 1.14 mm,the minimum RL of-39.3 dB at 16.1 GHz and effective absorption bandwidth of 3.7 GHz(from 14.3 to 18.0 GHz)can be achieved.This work indicates that In/C-Gr composites show excellent EMW absorption performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.61505175 and 61475134)the Natural Science Foundation of Hebei Province,China(Grant Nos.F2017203110 and F2017203193)
文摘Surface plasmon resonance induced tunable polarization filters based on nanoscale gold film-coated photonic crystal fibers were proposed and analyzed. The characteristics of the polarization filter were calculated by finite element method (FEM). The gold film was selectively coated on the inner wall of one cladding air hole which was located near the fiber core along the y-axis direction. When the phase of core fundamental mode and surface plasmon polaritons (SPPs) mode matches, the two modes couple with each other intensely. Numerical results show that the resonance wavelength and strength vary with fiber structural parameters and the index of the infilling liquid. The fiber parameters were optimized to achieve specific functions. Under the optimal structure, we realized a dual channel filter at the communication wavelength of 1.31 μm and 1.55 μm fory polarization direction and x polarization direction. Then a single channel polarized filter at the communication wavelength of 1.55 μm is also achieved by adjusting the refractive index of the infilling liquid. The proposed polarization filters realized dual channel filtering and single channel filtering simultaneously under the same structure for the first time to the best of our knowledge.
基金Supported by the National Natural Science Foundation of China。
文摘Double-crystal x-ray diffraction has been used to measure the rocking curve of Ta/Al multilayers.The diffraction profiles of the multilayers are different.Besides the normal profile,two kinds of distorted profiles have been found.The simulations show that the deformed profiles of the peaks are caused by the imperfect periodicity(e.g.systematic period deviation and coexistence of two slightly different periods)in the multilayers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51732010 and 51972280)the Natural Science Foundation of Hebei Province,China(Grant No.E2019203233)the Research Program of the College Science&Technology of Hebei Province,China(Grant No.ZD2020121).
文摘Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals heterostructures by a two-step chemical vapor deposition(CVD)method.After the growth of In_(2)Se_(3) at elevated temperatures,high densities of In_(2)Se_(3)/WS_(2) heterostructure bubbles with monolayer to multilayerβ-In_(2)Se_(3) crystals atop are observed.Fluorescence of the resultantβ-In_(2)Se_(3)/WS_(2) heterostructure is greatly enhanced in intensity upon the formation of bubbles,which are evidenced by the Newton’s rings in optical image owing to constructive and destructive interference.In photoluminescence(PL)mapping images of monolayerβ-In_(2)Se_(3)/monolayer WS2 heterobilayer bubble,significant oscillatory behavior of emission intensity is demonstrated due to constructive and destructive interference.However,oscillatory behaviors of peak position are also observed and come from a local heating effect induced by an excitation laser beam.The oscillatory mechanism of PL is further verified by changing the exterior pressure of bubbles placed in a home-made vacuum chamber.In addition,redshifted in peak position and broadening in peak width are observed due to strain effect during decreasing the exterior pressure of bubbles.
基金supported by the National Natural Science Foundation of China (51571172,51672240,51571171,and 11404280)the Natural Science Foundation for Distinguished Young Scholars of Hebei Province (E2017203095)+1 种基金the Natural Science Foundation of Hebei Province (E2016203484 and A2015203337)the Research Program of the College Science & Technology of Hebei Province (ZD2017083 and QN2014047)
基金supported by the National Natural Science Foundation of China (51732010,51571172,11404280,51672240 and 51571171)the Natural Science Foundation for Distinguished Young Scholars of Hebei Province (E2017203095)+2 种基金the Natural Science Foundation of Hebei Province (E2016203484 and A2015203337)the Research Program of the College Science & Technology of Hebei Province (ZD2017083 and QN2014047)the Graduate Innovation Fund (CXZZSS2017055 and 2017XJSS044)
文摘本文利用微波辅助水热法在碳布上快速合成了CoP纳米线阵列(CoP/CC)双功能电极材料,可用于析氢反应(HER)和超级电容器的电极.CoP/CC用于HER时展现了优越的电化学性能,其塔菲尔斜率为56 mV/dec.当电流密度为10 mA cm^(-2)时,其电位低至68 mV.值得注意的是,CoP/CC也可用于超级电容器的电极.在扫描速率为5 mV s^(-1)时,其比电容高达674 F g^(-1).同时具有高的循环稳定性,在循环10000次后,比电容仍然可以维持在初始值的86%.本文结果表明,CoP/CC可以作为HER和超级电容器电极的有力候选者.
基金We are grateful to the National Natural Science Foundation of China (51571172, 11404280, 51571171, 516722401, Natural Science Foundation for Distinguished Young Scholars of Hebei Province (E2017203095), Natural Science Foundation of Hebei Province (A2015203337, E2016203484), Science Foundation for the Excellent Youth Scholars from Universities and Colleges of Hebei Province (YQ2014009), and Research Program of the College Science & Technology of Hebei Province (ZD2017083, QN2014047).
文摘The three-dimensional nanoflower-like β-In2S3 composited with carbon nanotubes {CNTs) has been synthesized by a single mode micro- wave-assisted hydrothermal technique. The In2S3 and CNTs nanocomposites (In2S3@CNTs) were investigated as the anode materials of lithium batteries (LIBs) and the electromagnetic wave absorption materials. For LIBs applications, the In2S3@CNTs nanocomposite exhibited excellent cycling stability with a high reversible charge capacity of 575 mA·h·g-1 after 300 cycles at 0.S A·g^-1, In addition, the In2S3@CNTs used as electromagnetic wave absorber displayed a maximum reflection loss of-42.75 dB at 11.96 GHz with a thickness of 1.55 ram.
基金This work is supported by the National Natural Science Foundation of China(Nos.51732010,5197228051801175),and Natural Science Foundation of Hebei Province(No.E2019203233).
文摘Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.