Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental frien...Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental friendliness.However,its intrinsic low conductivity and sluggish Na^(+)diffusion restricted the fast-charge and low-temperature sodium storage.Herein,an NFPP composite encapsulated by in-situ pyrolytic carbon and coupled with expanded graphite(NFPP@C/EG)was constructed via a sol-gel method followed by a ballmill procedure.Due to the dual-carbon modified strategy,this NFPP@C/EG only enhanced the electronic conductivity,but also endowed more channels for Na^(+)diffusion.As cathode for SIBs,the optimized NFPP(M-NFPP@C/EG)delivers excellent rate capability(capacity of~80.5 mAh/g at 50 C)and outstanding cycling stability(11000 cycles at 50 C with capacity retention of 89.85%).Additionally,cyclic voltammetry(CV)confirmed that its sodium storage behavior is pseudocapacitance-controlled,with in-situ electrochemical impedance spectroscopy(EIS)further elucidating improvements in electrode reaction kinetics.At lower temperatures(0℃),M-NFPP@C/EG demonstrated exceptional cycling performance(8800 cycles at 10 C with capacity retention of 95.81%).Moreover,pouch cells also exhibited excellent stability.This research demonstrates the feasibility of a dual carbon modification strategy in enhancing NFPP and proposes a low-cost,high-rate,and ultra-stable cathode material for SIBs.展开更多
Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions.However,its practical appl...Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions.However,its practical applications are hampered by poor conductivity and large volume variation for Na^(+)storage,which resulting fast capacity decay.Herein,a facile metal-organic framework(MOF)derived method is explored to embed Cu_(2-x)Se@C particles into a carbon nanobelts matrix.Such carbon encapsulated nanobelts'structural moderate integral electronic conductivity and maintained the structure from collapsing during Na^(+)insertion/extraction.Furthermore,the porous structure of these nanobelts endows enough void space to mitigate volume stress and provide more diffusion channels for Na^(+)/electrons transporting.Due to the unique structure,these Cu_(2-x)Se@C nanobelts achieved ultra-stable cycling performance(170.7 m Ah/g at1.0 A/g after 1000 cycles)and superior rate capability(94.6 m Ah/g at 8 A/g)for sodium-ion batteries.The kinetic analysis reveals that these Cu_(2-x)Se@C nanobelts with considerable pesoudecapactive contribution benefit the rapid sodiation/desodiation.This rational design strategy broadens an avenue for the development of metal selenide materials for energy storage devices.展开更多
Hyperfluorescent organic light-emitting diodes(HF-OLEDs)approach has made it possible to achieve excellent device performance and color purity with low roll-off using noble-metal-free pure organic emitter.Despite sign...Hyperfluorescent organic light-emitting diodes(HF-OLEDs)approach has made it possible to achieve excellent device performance and color purity with low roll-off using noble-metal-free pure organic emitter.Despite significant progress,the performance of HF-OLEDs is still unsatisfactory due to the existence of a competitive dexter energy transfer(DET)pathway.In this contribution,two boron dipyrromethene(BODIPY)-based donor-acceptor emitters(BDP-C-Cz and BDP-N-Cz)with hybridized local and charge transfer characteristics(HLCT)are introduced in the HF-OLED to suppress the exciton loss by dexter mechanism,and a breakthrough performance with low-efficiency roll-off(0.3%)even at high brightness(1000 cd m^(-2))is achieved.It is demonstrated that the energy loss via the DET channel can be suppressed in HF-OLEDs utilizing the HLCT emitter,as the excitons from the dark triplet state of such emitters are funneled to its emissive singlet state following the hot-exciton mechanism.The developed HF-OLED device has realized a good maximum external quantum efficiency(EQE)of 19.25%at brightness of 1000 cd m^(-2)and maximum luminance over 60000 cd m^(-2),with an emission peak at 602 nm and Commission International de L'Eclairage(CIE)coordinates(0.57,0.41),which is among the best-achieved results in solution-processed HF-OLEDs.This work presents a viable methodology to suppress energy loss and achieve high performance in the HF-OLEDs.展开更多
Lithium-ion batteries(LIBs)gradually occupied the energy storage market due to their long cycling life;high working voltage;as well as energy density.However;LIBs have high costs due to the limited lithium resource an...Lithium-ion batteries(LIBs)gradually occupied the energy storage market due to their long cycling life;high working voltage;as well as energy density.However;LIBs have high costs due to the limited lithium resource and difficulty to exploit.Potassium ion batteries(PIBs)have aroused extensive attention over the past few years since they possess considerable potassium salt resources while exhibiting similar electrochemical properties to LIBs.The electrode material takes on great significance in determining the properties exhibited by the batteries.Zinc-based chalcogenides have served as the most suitable anode materials for their numerous raw material resources;low prices;and environmental friendliness.Nevertheless;the application of Zinc-based chalcogenides has been continuously hindered by sluggish diffusion kinetics;low electrical conductivity;as well as huge volume vari-ation.Several effective strategies have been explored to settle the above matters(e.g.;designing nanostructures;constructing carbon composite structures;as well as doping anions or cations to construct heterojunction).In this review;the recent advance of zinc-based chalcogenides(e.g.;electrochemical mechanisms;challenges;and perspectives)are summarized.This review can provide novel insights into the development of transition metal chalcogenides for PIBs.展开更多
Triplet-triplet annihilation(TTA) upconversion-based materials have potential application in the broad range of research areas, including photocatalysis and life sciences. However, near-infrared(NIR)-to-blue upconvert...Triplet-triplet annihilation(TTA) upconversion-based materials have potential application in the broad range of research areas, including photocatalysis and life sciences. However, near-infrared(NIR)-to-blue upconverted emission is preferred for most of the practical applications, but developing a NIR-to-blue TTA upconversion system is a challenging task in photochemistry. In this work, a thermally activated delayed fluorescence(TADF) material with intense visible-to-NIR absorption is demonstrated that shows a longer triplet state lifetime(32 μs) and high triplet state energy(E_(T)= 1.55 e V). For the first time, a heavy atomfree NIR(λ_(ex)> 650 nm) to blue(λ_(em)< 460 nm) TTA upconversion system was devised, employing the dimeric borondifluoride curcuminoid TADF material as triplet photosensitizer(PS) and a large anti-Stokes shift(0.88 e V) along with moderate upconversion yield was achieved. Our work provides the solution and guidance for the future development of purely organic heavy atom-free NIR activating TTA upconversion system for a wide array of applications.展开更多
Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare.In this work,we report on one such novel monopept...Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare.In this work,we report on one such novel monopeptide-based transporter system,featuring both chalcogen bonds for highly efficient anion transport and high transport selectivity toward ClO_(4)^(-) anions.Structurally,these monopeptide molecules associate with each other via H-bonds to produce H-bonded 1D stack that not only one dimensionally but also directionally aligns the terminal bicyclic thiophene motifs to the same side.Functionally,these well-aligned thiophenes create a sulfur-rich transmembrane pathway,combinatorially fine-tunable to enable anions to efficiently cross the membrane in the increasing activity of Cl^(-)<Br^(-)<NO_(3)^(-)<ClO_(4)^(-) via chalcogen bonds,with EC_(50)values of 0.75,0.40,0.37 and 0.093μmol/L(0.3 mol%relative to lipid molecules),respectively.展开更多
Herein,we disclose a novel copper-catalyzed C(sp)-H aryl amination of terminal alkynes with anthranils,enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structural...Herein,we disclose a novel copper-catalyzed C(sp)-H aryl amination of terminal alkynes with anthranils,enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structurally diverse C2-substituted quinolines and 2-quinolinones.The in-situ formed carbonyl-ynamines are prone to tautomerize to carbonyl-ketenimines,which can efficiently react with a series of nucleophiles,including amines,alcohols,phenols,thiols,thiophenols,active-methylene compounds,and even water to produce various quinoline derivatives with the generation of H_(2)O as a sole and green byproduct.This method also unlocks a practical route to create various quinoline-fused heterocycles and can be successfully applied to the late-stage modification of complex molecules and the concise synthesis of bioactive targets.Mechanistic studies reveal a coppercatalyzed inner-sphere nitrene transfer process by using anthranils as novel aryl nitrene precursors.展开更多
By employing the asymmetric end-group engineering,an asymmetric nonfused-ring electron acceptor(NFREA)was designed and synthesized.Compared with the symmetric analogs(NoCA-17 and NoCA-18),NoCA-19 possesses broader lig...By employing the asymmetric end-group engineering,an asymmetric nonfused-ring electron acceptor(NFREA)was designed and synthesized.Compared with the symmetric analogs(NoCA-17 and NoCA-18),NoCA-19 possesses broader light absorption range,more coplanarπ-conjugated backbone,and appropriate crystallinity according to the experimental and theoretical results.The organic solar cells based on J52:NoCA-19 exhibited a power conversion efficiency as high as 12.26%,which is much higher than those of J52:NoCA-17(9.50%)and J52:NoCA-18(11.77%),mainly due to more efficient exciton dissociation,better and balanced charge mobility,suppressed recombination loss,shorter charge extraction time,longer charge carrier lifetimes,and more favorable blend film morphology.These findings demonstrate the great potential of asymmetric end-group engineering in exploring low-cost and high-performance NFREAs.展开更多
The unfavorable photochemical processes at the molecular level have become a bar-rier limiting the use of aromatic amides as high-performance luminescent materials.Herein,we propose a reliable strategy for manipulatin...The unfavorable photochemical processes at the molecular level have become a bar-rier limiting the use of aromatic amides as high-performance luminescent materials.Herein,we propose a reliable strategy for manipulating noncovalent conformational lock(NCL)via side-chain engineering to burst out eye-catching luminescence at the aggregate level.Contrary to the invisible emission in dilute solutions,dyad OO with a three-centered H-bond gave the wondrous crystallization-induced emis-sion with a quantum yield of 66.8%and clusterization-triggered emission,which were much brighter than those of isomers.Theoretical calculations demonstrate that crystallization-induced planarized intramolecular charge transfer(PICT),con-formation rigidification,and through-space conjugation(TSC)are responsible for aggregate-state luminescence.Robust NCL composed of intramolecular N-H⋅⋅⋅Ointeractions could boost molecular rigidity and planarity,thus greatly facilitating PICT and TSC.This study would inspire researchers to design efficient luminescent materials at the aggregate level via rational conformational control.展开更多
Multi-resonance thermally activated delayed fluorescence(MR-TADF)materials are promising candidates for organic light-emitting diodes(OLEDs)with narrow electroluminescence(EL)spectra.Current researches focus on fabric...Multi-resonance thermally activated delayed fluorescence(MR-TADF)materials are promising candidates for organic light-emitting diodes(OLEDs)with narrow electroluminescence(EL)spectra.Current researches focus on fabricating hyperfluorescence OLEDs to improve EL efficiencies of MR-TADF emitters by co-doping them with TADF sensitizers in a single host layer.However,in many cases,the polarity of the single host could be not suitable for both blue MRTADF emitters and blue TADF sensitizers,resulting in broadened EL spectra in high-polar hosts or decreased EL efficiencies in low-polar hosts.Herein,we wish to report an efficient sensitization strategy for blue MR-TADF emitters by constructing an interlayer-sensitizing configuration,in which the blue TADF sensitizers and blue MR-TADF emitters are separated into two closely aligned host layers with high polarity and low polarity,respectively.Based on this strategy,efficient blue hyperfluorescence OLEDs are realized and verified by employing various TADF sensitizers and different MR-TADF emitters,furnishing outstanding external quantum efficiencies of up to 38.8%and narrow EL spectra.These results validate the feasibility and universality of this interlayer sensitization strategy,which provides an effective alternative to high-performance blue hyperfluorescence OLEDs.展开更多
Covalent organic frameworks(COFs),a novel class of crystalline porous materials constructed by covalent bonds,possess ordered porous structures via thermodynamically controlled polymerization reactions.Because of thei...Covalent organic frameworks(COFs),a novel class of crystalline porous materials constructed by covalent bonds,possess ordered porous structures via thermodynamically controlled polymerization reactions.Because of their structurally diverse,regular pore structures,high surface area,and thermal stability can be functionally tailored through different synthetic methods to meet the needs of various applications including for secondary batteries.This review summarized recent efforts that have been devoted to designing and synthesizing COF-based materials for battery applications,including electrode materials,electrolytes,and separators.Unique characteristics of COFs allow for the rational design of targeted functions,suppression of side reactions,and promotion of ion transport for batteries.This review clarified recent research progress on COF materials for lithium-ion batteries,lithium-sulfur batteries,sodium-ion batteries,potassium-ion batteries and so on.This review pointed out the structure and chemical properties of COFs,as well as new strategies to improve battery performance.Furthermore,we concluded the major challenges and future trends of COF materials in electrochemical applications.It is hoped that this review will provide meaningful guidance for the development of COFs for alkali-ion batteries.展开更多
Three new deep blue light emitters,bearing quinoxaline with different substituents(biphenyl/pyrene)at the 1-or 2-position,were synthesized by a Pd-catalysed coupling reaction in high yields,and were fully characterize...Three new deep blue light emitters,bearing quinoxaline with different substituents(biphenyl/pyrene)at the 1-or 2-position,were synthesized by a Pd-catalysed coupling reaction in high yields,and were fully characterized by 1H/13C NMR spectroscopy,single crystal X-ray diffraction,and high-resolution mass spectrometry(HRMS).展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFB2502000)the National Natural Science Foundation of China(Nos.U21A20332,51771076,U21A200970,52301266)the Science and Technology Planning Project of Guangzhou(No.2024A04J3332)。
文摘Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental friendliness.However,its intrinsic low conductivity and sluggish Na^(+)diffusion restricted the fast-charge and low-temperature sodium storage.Herein,an NFPP composite encapsulated by in-situ pyrolytic carbon and coupled with expanded graphite(NFPP@C/EG)was constructed via a sol-gel method followed by a ballmill procedure.Due to the dual-carbon modified strategy,this NFPP@C/EG only enhanced the electronic conductivity,but also endowed more channels for Na^(+)diffusion.As cathode for SIBs,the optimized NFPP(M-NFPP@C/EG)delivers excellent rate capability(capacity of~80.5 mAh/g at 50 C)and outstanding cycling stability(11000 cycles at 50 C with capacity retention of 89.85%).Additionally,cyclic voltammetry(CV)confirmed that its sodium storage behavior is pseudocapacitance-controlled,with in-situ electrochemical impedance spectroscopy(EIS)further elucidating improvements in electrode reaction kinetics.At lower temperatures(0℃),M-NFPP@C/EG demonstrated exceptional cycling performance(8800 cycles at 10 C with capacity retention of 95.81%).Moreover,pouch cells also exhibited excellent stability.This research demonstrates the feasibility of a dual carbon modification strategy in enhancing NFPP and proposes a low-cost,high-rate,and ultra-stable cathode material for SIBs.
基金supported by the National Key Research and Development Program of China(No.2022YFB2502000)the National Natural Science Foundation of China(Nos.U21A2033251771076,52301266,42203047)+2 种基金R&D Program in Key Areas of Guangdong Province(No.2020B0101030005)Science and Technology Planning Project of Guangzhou(No.2024A04J9999)GDUT Large-Scale Instruments Open Foundation(No.ATC2022201)。
文摘Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions.However,its practical applications are hampered by poor conductivity and large volume variation for Na^(+)storage,which resulting fast capacity decay.Herein,a facile metal-organic framework(MOF)derived method is explored to embed Cu_(2-x)Se@C particles into a carbon nanobelts matrix.Such carbon encapsulated nanobelts'structural moderate integral electronic conductivity and maintained the structure from collapsing during Na^(+)insertion/extraction.Furthermore,the porous structure of these nanobelts endows enough void space to mitigate volume stress and provide more diffusion channels for Na^(+)/electrons transporting.Due to the unique structure,these Cu_(2-x)Se@C nanobelts achieved ultra-stable cycling performance(170.7 m Ah/g at1.0 A/g after 1000 cycles)and superior rate capability(94.6 m Ah/g at 8 A/g)for sodium-ion batteries.The kinetic analysis reveals that these Cu_(2-x)Se@C nanobelts with considerable pesoudecapactive contribution benefit the rapid sodiation/desodiation.This rational design strategy broadens an avenue for the development of metal selenide materials for energy storage devices.
基金supported by Guangdong Foundation of Basic and Applied Basic Research(2019B1515120023,2022B1515020041)National Natural Science Foundation of China(21975053,21975055,U2001222)for financial support
文摘Hyperfluorescent organic light-emitting diodes(HF-OLEDs)approach has made it possible to achieve excellent device performance and color purity with low roll-off using noble-metal-free pure organic emitter.Despite significant progress,the performance of HF-OLEDs is still unsatisfactory due to the existence of a competitive dexter energy transfer(DET)pathway.In this contribution,two boron dipyrromethene(BODIPY)-based donor-acceptor emitters(BDP-C-Cz and BDP-N-Cz)with hybridized local and charge transfer characteristics(HLCT)are introduced in the HF-OLED to suppress the exciton loss by dexter mechanism,and a breakthrough performance with low-efficiency roll-off(0.3%)even at high brightness(1000 cd m^(-2))is achieved.It is demonstrated that the energy loss via the DET channel can be suppressed in HF-OLEDs utilizing the HLCT emitter,as the excitons from the dark triplet state of such emitters are funneled to its emissive singlet state following the hot-exciton mechanism.The developed HF-OLED device has realized a good maximum external quantum efficiency(EQE)of 19.25%at brightness of 1000 cd m^(-2)and maximum luminance over 60000 cd m^(-2),with an emission peak at 602 nm and Commission International de L'Eclairage(CIE)coordinates(0.57,0.41),which is among the best-achieved results in solution-processed HF-OLEDs.This work presents a viable methodology to suppress energy loss and achieve high performance in the HF-OLEDs.
基金supported by the National Key Research and Devel-opment Program of China(no.2022YFB2502000)the National Natural Science Foundation of China(no.U21A2033251771076)+1 种基金Guangdong Basic and Applied Basic Research Foundation(nos.2020B1515120049,2021A1515010332 and 2021A1515010153)R&D Program in Key Areas of Guangdong Province(no.2020B0101030005).
文摘Lithium-ion batteries(LIBs)gradually occupied the energy storage market due to their long cycling life;high working voltage;as well as energy density.However;LIBs have high costs due to the limited lithium resource and difficulty to exploit.Potassium ion batteries(PIBs)have aroused extensive attention over the past few years since they possess considerable potassium salt resources while exhibiting similar electrochemical properties to LIBs.The electrode material takes on great significance in determining the properties exhibited by the batteries.Zinc-based chalcogenides have served as the most suitable anode materials for their numerous raw material resources;low prices;and environmental friendliness.Nevertheless;the application of Zinc-based chalcogenides has been continuously hindered by sluggish diffusion kinetics;low electrical conductivity;as well as huge volume vari-ation.Several effective strategies have been explored to settle the above matters(e.g.;designing nanostructures;constructing carbon composite structures;as well as doping anions or cations to construct heterojunction).In this review;the recent advance of zinc-based chalcogenides(e.g.;electrochemical mechanisms;challenges;and perspectives)are summarized.This review can provide novel insights into the development of transition metal chalcogenides for PIBs.
基金the National Natural Science Foundation of China (Nos. 21975053, 21975055, U2001222)Guangdong Basic and Applied Basic Research Foundation (Nos. 2019B1515120023, 2022B1515020041)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2019) for financial support。
文摘Triplet-triplet annihilation(TTA) upconversion-based materials have potential application in the broad range of research areas, including photocatalysis and life sciences. However, near-infrared(NIR)-to-blue upconverted emission is preferred for most of the practical applications, but developing a NIR-to-blue TTA upconversion system is a challenging task in photochemistry. In this work, a thermally activated delayed fluorescence(TADF) material with intense visible-to-NIR absorption is demonstrated that shows a longer triplet state lifetime(32 μs) and high triplet state energy(E_(T)= 1.55 e V). For the first time, a heavy atomfree NIR(λ_(ex)> 650 nm) to blue(λ_(em)< 460 nm) TTA upconversion system was devised, employing the dimeric borondifluoride curcuminoid TADF material as triplet photosensitizer(PS) and a large anti-Stokes shift(0.88 e V) along with moderate upconversion yield was achieved. Our work provides the solution and guidance for the future development of purely organic heavy atom-free NIR activating TTA upconversion system for a wide array of applications.
基金supported by the construct program of applied characteristic discipline in Hunan University of Science and Engineering,the Technology Plan of Guangdong Province(No. 2019A050510042)the Natural Science Foundation of Hunan Province of China (No. 2021JJ30291)Northwestern Polytechnical University。
文摘Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare.In this work,we report on one such novel monopeptide-based transporter system,featuring both chalcogen bonds for highly efficient anion transport and high transport selectivity toward ClO_(4)^(-) anions.Structurally,these monopeptide molecules associate with each other via H-bonds to produce H-bonded 1D stack that not only one dimensionally but also directionally aligns the terminal bicyclic thiophene motifs to the same side.Functionally,these well-aligned thiophenes create a sulfur-rich transmembrane pathway,combinatorially fine-tunable to enable anions to efficiently cross the membrane in the increasing activity of Cl^(-)<Br^(-)<NO_(3)^(-)<ClO_(4)^(-) via chalcogen bonds,with EC_(50)values of 0.75,0.40,0.37 and 0.093μmol/L(0.3 mol%relative to lipid molecules),respectively.
基金supported by the National Natural Science Foundation of China (22271065,22271314)the Guangzhou Basic and Applied Research (202201010396)。
文摘Herein,we disclose a novel copper-catalyzed C(sp)-H aryl amination of terminal alkynes with anthranils,enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structurally diverse C2-substituted quinolines and 2-quinolinones.The in-situ formed carbonyl-ynamines are prone to tautomerize to carbonyl-ketenimines,which can efficiently react with a series of nucleophiles,including amines,alcohols,phenols,thiols,thiophenols,active-methylene compounds,and even water to produce various quinoline derivatives with the generation of H_(2)O as a sole and green byproduct.This method also unlocks a practical route to create various quinoline-fused heterocycles and can be successfully applied to the late-stage modification of complex molecules and the concise synthesis of bioactive targets.Mechanistic studies reveal a coppercatalyzed inner-sphere nitrene transfer process by using anthranils as novel aryl nitrene precursors.
基金the financial support fromtheNSFC(21975055,U2001222,52103352,52120105006,and 51925306)National Key R&D Program of China(2018FYA 0305800)+2 种基金Key Research Program of Chinese Academy of Sciences(XDPB08-2)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022165)the Fundamental Research Funds for the Central Universities.DFT results described in this article were obtained from the National Supercomputing Centre in Shenzhen(Shenzhen Cloud Computing Centre).
文摘By employing the asymmetric end-group engineering,an asymmetric nonfused-ring electron acceptor(NFREA)was designed and synthesized.Compared with the symmetric analogs(NoCA-17 and NoCA-18),NoCA-19 possesses broader light absorption range,more coplanarπ-conjugated backbone,and appropriate crystallinity according to the experimental and theoretical results.The organic solar cells based on J52:NoCA-19 exhibited a power conversion efficiency as high as 12.26%,which is much higher than those of J52:NoCA-17(9.50%)and J52:NoCA-18(11.77%),mainly due to more efficient exciton dissociation,better and balanced charge mobility,suppressed recombination loss,shorter charge extraction time,longer charge carrier lifetimes,and more favorable blend film morphology.These findings demonstrate the great potential of asymmetric end-group engineering in exploring low-cost and high-performance NFREAs.
基金financially supported by the National Natural Science Foundation of China(grant numbers 22205040,U2001222,and 52273168)the Basic and Applied Basic Research Foundation of Guangdong Province(grant number 2021A1515110417)J.Zhang acknowledges the support from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie actions grant(101105790)。
文摘The unfavorable photochemical processes at the molecular level have become a bar-rier limiting the use of aromatic amides as high-performance luminescent materials.Herein,we propose a reliable strategy for manipulating noncovalent conformational lock(NCL)via side-chain engineering to burst out eye-catching luminescence at the aggregate level.Contrary to the invisible emission in dilute solutions,dyad OO with a three-centered H-bond gave the wondrous crystallization-induced emis-sion with a quantum yield of 66.8%and clusterization-triggered emission,which were much brighter than those of isomers.Theoretical calculations demonstrate that crystallization-induced planarized intramolecular charge transfer(PICT),con-formation rigidification,and through-space conjugation(TSC)are responsible for aggregate-state luminescence.Robust NCL composed of intramolecular N-H⋅⋅⋅Ointeractions could boost molecular rigidity and planarity,thus greatly facilitating PICT and TSC.This study would inspire researchers to design efficient luminescent materials at the aggregate level via rational conformational control.
基金the National Natural Science Foundation of China(22375066,U23A20594 and 21788102)the GuangDong Basic and Applied Basic Research Foundation(2023B1515040003 and 2022A1515010315).
文摘Multi-resonance thermally activated delayed fluorescence(MR-TADF)materials are promising candidates for organic light-emitting diodes(OLEDs)with narrow electroluminescence(EL)spectra.Current researches focus on fabricating hyperfluorescence OLEDs to improve EL efficiencies of MR-TADF emitters by co-doping them with TADF sensitizers in a single host layer.However,in many cases,the polarity of the single host could be not suitable for both blue MRTADF emitters and blue TADF sensitizers,resulting in broadened EL spectra in high-polar hosts or decreased EL efficiencies in low-polar hosts.Herein,we wish to report an efficient sensitization strategy for blue MR-TADF emitters by constructing an interlayer-sensitizing configuration,in which the blue TADF sensitizers and blue MR-TADF emitters are separated into two closely aligned host layers with high polarity and low polarity,respectively.Based on this strategy,efficient blue hyperfluorescence OLEDs are realized and verified by employing various TADF sensitizers and different MR-TADF emitters,furnishing outstanding external quantum efficiencies of up to 38.8%and narrow EL spectra.These results validate the feasibility and universality of this interlayer sensitization strategy,which provides an effective alternative to high-performance blue hyperfluorescence OLEDs.
基金supported by the National Key Research and Development Program of China(no.2022YFB2502000)the National Natural Science Foundation of China(nos.U21A2033251771076 and 52301266)+1 种基金Guangdong Basic and Applied Basic Research Foundation(nos.2020B1515120049 and 2021A1515010332)R&D Program in Key Areas of Guangdong Province(no.2020B0101030005).
文摘Covalent organic frameworks(COFs),a novel class of crystalline porous materials constructed by covalent bonds,possess ordered porous structures via thermodynamically controlled polymerization reactions.Because of their structurally diverse,regular pore structures,high surface area,and thermal stability can be functionally tailored through different synthetic methods to meet the needs of various applications including for secondary batteries.This review summarized recent efforts that have been devoted to designing and synthesizing COF-based materials for battery applications,including electrode materials,electrolytes,and separators.Unique characteristics of COFs allow for the rational design of targeted functions,suppression of side reactions,and promotion of ion transport for batteries.This review clarified recent research progress on COF materials for lithium-ion batteries,lithium-sulfur batteries,sodium-ion batteries,potassium-ion batteries and so on.This review pointed out the structure and chemical properties of COFs,as well as new strategies to improve battery performance.Furthermore,we concluded the major challenges and future trends of COF materials in electrochemical applications.It is hoped that this review will provide meaningful guidance for the development of COFs for alkali-ion batteries.
基金This work was supported by the National Natural Science Foundation of China(Nos.21975054 and 21602014)the Natural Science Foundation of Guangdong Provinee of China(No.2019A1515010925)+2 种基金the Guangdong Provincial Key Laboratory of Information Photonics Technology(No.2020B121201011)the"One Hundred Talents Program"of the Guangdong University of Technology(No.1108-220413205)the Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter of The Guang-dong University of Technology(No.220413205).
文摘Three new deep blue light emitters,bearing quinoxaline with different substituents(biphenyl/pyrene)at the 1-or 2-position,were synthesized by a Pd-catalysed coupling reaction in high yields,and were fully characterized by 1H/13C NMR spectroscopy,single crystal X-ray diffraction,and high-resolution mass spectrometry(HRMS).
