Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize n...Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature.Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the pos-sibility of aggregation-caused quenching.Photoelectrical measurements and electric band structure cal-culation both verify the superiority of this oCOFs’structure in photoelectric sensing.展开更多
In this work,we demonstrate that an organometallic perovskite(OP)single crystal for effective photodetection can be grown on a gold(Au)-decorated substrate using liquid phase epitaxy.The covered gold could both contro...In this work,we demonstrate that an organometallic perovskite(OP)single crystal for effective photodetection can be grown on a gold(Au)-decorated substrate using liquid phase epitaxy.The covered gold could both control the shape of the epitaxial layer and act as its electrodes.An MAPbCl3 single crystal and an MAPbBr1.5Cl1.5 single crystal were used as the substrate and the epitaxial layer,respectively.The device,with an Au-perovskite-Au structure,can be fully characterized.Due to the high-quality epitaxial layer,the maximum external quantum efficiency(EQE)value is over 60%under the voltage of20 V.In addition,the response speed can reach 200 and 500 ns(ns)rise and fall,respectively.Our work provides an effective and promising method to fabricate efficient perovskite-based photodetectors.展开更多
4H-SiC single photon counting avalanche photodiodes(SPADs)are prior devices for weak ultraviolet(UV)signal detection with the advantages of small size,low leakage current,high avalanche multiplication gain,and high qu...4H-SiC single photon counting avalanche photodiodes(SPADs)are prior devices for weak ultraviolet(UV)signal detection with the advantages of small size,low leakage current,high avalanche multiplication gain,and high quantum efficiency,which benefit from the large bandgap energy,high carrier drift velocity and excellent physical stability of 4 H-SiC semiconductor material.UV detectors are widely used in many key applications,such as missile plume detection,corona discharge,UV astronomy,and biological and chemical agent detection.In this paper,we will describe basic concepts and review recent results on device design,process development,and basic characterizations of 4 H-SiC avalanche photodiodes.Several promising device structures and uniformity of avalanche multiplication are discussed,which are important for achieving high performance of 4 HSiC UV SPADs.展开更多
A novel hydrogen-bonded organic frameworks(HOFs)FJU-200 has been constructed from N,N’-bis(5-isophthalic acid)naphthalimide(H_(4)L).FJU-200 has a good dual-function of aniline and ultraviolet detection.FJU-200 is the...A novel hydrogen-bonded organic frameworks(HOFs)FJU-200 has been constructed from N,N’-bis(5-isophthalic acid)naphthalimide(H_(4)L).FJU-200 has a good dual-function of aniline and ultraviolet detection.FJU-200 is the first case of HOF with dual sensing of visual color changes and photoluminescence quenching for aniline detection,and the detection limit of aniline can reach5.5 x 10^(-4)mol/L.Under ultraviolet FJU-200 will rapidly change from light yellow to rustic brown,which makes it possible to use FJU-200 to achieve minute-level ultraviolet detection.Moreover,for more convenient use,FJU-200 test papers are prepared.Using them,convenient and fast aniline or ultraviolet detection can be realized.The single-crystal X-ray structures show that compared with the original FJU-200,both PhNH_(2)@FJU-200 and UV-FJU-200 have larger pore sizes,and the dihedral angles of the H_(2)L^(2-)in framework has been changed.展开更多
The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion ...The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.展开更多
基金supported by the National Key R&D Program of China(Nos.2021YFE0201400,2018YFA0703200,2020YFA0308800)National Natural Science Foundation of China(Nos.51773041,61890940,21603038,11974045)Shanghai Com-mittee of Science and Technology in China(No.18ZR1404900).
文摘Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature.Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the pos-sibility of aggregation-caused quenching.Photoelectrical measurements and electric band structure cal-culation both verify the superiority of this oCOFs’structure in photoelectric sensing.
基金the National Key R&D Program of China(2017YFC0111500 and 2016YFB0401600)the National Natural Science Foundation Project(61775034,61571124,and 61674029)+1 种基金the Taizhou Key Technology R&D Program(TS201716)the NSFC Research Fund for International Young Scientists(61750110537).
文摘In this work,we demonstrate that an organometallic perovskite(OP)single crystal for effective photodetection can be grown on a gold(Au)-decorated substrate using liquid phase epitaxy.The covered gold could both control the shape of the epitaxial layer and act as its electrodes.An MAPbCl3 single crystal and an MAPbBr1.5Cl1.5 single crystal were used as the substrate and the epitaxial layer,respectively.The device,with an Au-perovskite-Au structure,can be fully characterized.Due to the high-quality epitaxial layer,the maximum external quantum efficiency(EQE)value is over 60%under the voltage of20 V.In addition,the response speed can reach 200 and 500 ns(ns)rise and fall,respectively.Our work provides an effective and promising method to fabricate efficient perovskite-based photodetectors.
基金supported in part by National Key R&D Program of China under Grant No. 2016YFB0400902in part by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘4H-SiC single photon counting avalanche photodiodes(SPADs)are prior devices for weak ultraviolet(UV)signal detection with the advantages of small size,low leakage current,high avalanche multiplication gain,and high quantum efficiency,which benefit from the large bandgap energy,high carrier drift velocity and excellent physical stability of 4 H-SiC semiconductor material.UV detectors are widely used in many key applications,such as missile plume detection,corona discharge,UV astronomy,and biological and chemical agent detection.In this paper,we will describe basic concepts and review recent results on device design,process development,and basic characterizations of 4 H-SiC avalanche photodiodes.Several promising device structures and uniformity of avalanche multiplication are discussed,which are important for achieving high performance of 4 HSiC UV SPADs.
基金supported by the National Natural Science Foundation of China(Nos.21673039,21573042,21805039,21975044,21971038 and 21922810)the Fujian Provincial Department of Science and Technology(Nos.2018J07001 and2019H6012)。
文摘A novel hydrogen-bonded organic frameworks(HOFs)FJU-200 has been constructed from N,N’-bis(5-isophthalic acid)naphthalimide(H_(4)L).FJU-200 has a good dual-function of aniline and ultraviolet detection.FJU-200 is the first case of HOF with dual sensing of visual color changes and photoluminescence quenching for aniline detection,and the detection limit of aniline can reach5.5 x 10^(-4)mol/L.Under ultraviolet FJU-200 will rapidly change from light yellow to rustic brown,which makes it possible to use FJU-200 to achieve minute-level ultraviolet detection.Moreover,for more convenient use,FJU-200 test papers are prepared.Using them,convenient and fast aniline or ultraviolet detection can be realized.The single-crystal X-ray structures show that compared with the original FJU-200,both PhNH_(2)@FJU-200 and UV-FJU-200 have larger pore sizes,and the dihedral angles of the H_(2)L^(2-)in framework has been changed.
文摘The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.
