Dual-phase titanium alloys are widely employed as ultrasonic waveguide materials for medical applications.However,the mechanisms underlying the interaction between microstructure and ultrasonic propagation in the allo...Dual-phase titanium alloys are widely employed as ultrasonic waveguide materials for medical applications.However,the mechanisms underlying the interaction between microstructure and ultrasonic propagation in the alloy remain unclear.Herein,variations in the ultrasonic attenuation behavior of medical extra-low-interstitial-grade Ti6A14V alloys with microstructure evolution are systematically investigated.Experimental results demonstrate that within a d(grain size)/λ(wavelength)range of 0.1-1,scattering attenuation and dislocation damping are the key factors affecting ultrasonic attenuation.Longitudinal-wave scattering attenuation is directly proportional to the grain size,and dislocation damping is primarily influenced by the orientation of α grains.In particular,dislocation slip on the prismatic planes of αgrains is found to be a key factor influencing the dislocation-damping effect for dual-phase Ti alloys.This can be attributed to the oscillatory movement of dislocations in response to ultrasonic-wave disturbance when the wave propagation direction is parallel to the prismatic planes of αgrains,causing energy dissipation.Further,the mechanisms by which dislocation types and movement patterns influence ultrasonic attenuation are discussed in detail based on a G-L dislocation pinning model.展开更多
This study demonstrates that the integration of plasmonic palladium(Pd)nanoparticles between a bismuth vanadate(BVO)coating and an electrode interface can significantly improve solar-driven glycerol oxidation.Pd nanop...This study demonstrates that the integration of plasmonic palladium(Pd)nanoparticles between a bismuth vanadate(BVO)coating and an electrode interface can significantly improve solar-driven glycerol oxidation.Pd nanoparticles of controllable shape,size and coverage were produced using a novel aerosol-assisted chemical vapour deposition(AACVD)synthetic route and then coated with BVO using the same technique.The nanoparticles enhanced visible light absorption and crystallinity.At 1.23 VRHE,the photocurrent density of bare BVO increased from 0.62 mA cm^(-2) in the absence of glycerol to 1.20 mA cm^(-2) with 0.5 M glycerol.When Pd nanoparticles were incorporated beneath BVO,the photocurrent further increased from 0.86 mA cm^(-2) without glycerol to 1.58 mA cm^(-2) with 0.5 M glycerol,and the incident photon-to-current conversion efficiency(IPCE)boosted from~15%to~40%at 400 nm.Ultra-fast transient absorption spectroscopy suggests that the addition of Pd nanoparticles introduces additional charge transfer pathways,including hot electron injection and plasmon-coupled states,which prolong carrier lifetimes and suppress recombination.These combined effects provide a promising strategy to improve the efficiency and durability of photoelectrochemical devices for sustainable fuel generation and selective organic oxidation reactions.展开更多
The development of high-performance organic solar cells(OSCs)with high operational stability is essential to accelerate their commercialization.Unfortunately,our understanding of the origin of instabilities in state-o...The development of high-performance organic solar cells(OSCs)with high operational stability is essential to accelerate their commercialization.Unfortunately,our understanding of the origin of instabilities in state-of-the-art OSCs based on bulk heterojunction(BHJ)featuring non-fullerene acceptors(NFAs)remains limited.Herein,we developed NFA-based OSCs using different charge extraction interlayer materials and studied their storage,thermal,and operational stabilities.Despite the high power conversion efficiency(PCE)of the OSCs(17.54%),we found that cells featuring self-assembled monolayers(SAMs)as hole-extraction interlayers exhibited poor stability.The time required for these OSCs to reach 80%of their initial performance(T_(80))was only 6h under continuous thermal stress at 85℃in a nitrogen atmosphere and 1 h under maximum power point tracking(MPPT)in a vacuum.Inserting MoO_(x)between ITO and SAM enhanced the T_(80)to 50 and~15 h after the thermal and operational stability tests,respectively,while maintaining a PCE of 16.9%.Replacing the organic PDINN electron transport layer with ZnO NPs further enhances the cells'thermal and operational stability,boosting the T_(80)to 1000 and 170 h,respectively.Our work reveals the synergistic roles of charge-selective interlayers and device architecture in developing efficient and stable OSCs.展开更多
The power conversion efficiencies(PCEs)of single-junction organic solar cells(OSCs)have surpassed 19%,owing to the emerging Y-series nonfullerene acceptors(NFAs).Undoubtedly,the power and flexibility of chemical desig...The power conversion efficiencies(PCEs)of single-junction organic solar cells(OSCs)have surpassed 19%,owing to the emerging Y-series nonfullerene acceptors(NFAs).Undoubtedly,the power and flexibility of chemical design has been a strong driver for this rapid efficiency improvement in the OSC field.Over the course of the past 3 years,a variety of modifications have been made to the structure of the Y6 acceptor,and a large number of Y-series NFAs have been reported to further improve performance.Herein,we present our insights into the rationale behind the Y6 acceptor and discuss the design principles toward high-performance Y-series NFAs.It is clear that structural modifications through choice of heteroatom,soluble chains,πspacers,central cores,and end groups alter the material characteristics and properties,contributing to distinctive photovoltaic performance.Subsequently,we analyze various design strategies of Y-series-containing materials,including polymerized small-molecule acceptors(PSMA),non-fused-ring acceptors(NFRA),and all-fused-ring acceptors(AFRA).This review is expected to be of value in providing effective molecular design strategies for high-performance NFAs in future innovations.展开更多
Hot carrier cooling is slowed down upon alloying tin in lead-halide perovskite nanocrystals through the engineering of carrier-phonon and carrier-defect interactions.
Ultra-flexible organic photovoltaics(OPVs)are promising candidates for next-generation power sources owing to their low weight,transparency,and flexibility.However,obtaining ultra-flexibility under extreme repetitive ...Ultra-flexible organic photovoltaics(OPVs)are promising candidates for next-generation power sources owing to their low weight,transparency,and flexibility.However,obtaining ultra-flexibility under extreme repetitive mechanical stress while maintaining optical transparency remains challenging because of the intrinsic brittleness of transparent electrodes.Here,we introduce straindurable ultra-flexible semitransparent OPVs with a thickness below 2μm.The conformal surface coverage of nanoscale thin metal electrodes(<10 nm)is achieved,resulting in extremely low flexural rigidity and high strain durability.In-depth optical and electrical analyses on ultrathin metal electrodes showed that the devices maintain over 73%of their initial efficiency after 1000 cycles of repetitive compression and release at 66%compressive strain,and the average visible light transmittances remain higher than 30%.To our knowledge,this is the first systematical study on mechanical behaviors of strain-durable ultra-flexible ST-OPVs through precise adjustment of each ultrathin electrode thickness toward the emergence of next-generation flexible power sources.展开更多
基金financially supported by the National Natural Science Foundation of China(No.12364011)the Natural Science Foundation of Guangxi Zhuang Autonomous Region(No.2024GXNSFBA010109)
文摘Dual-phase titanium alloys are widely employed as ultrasonic waveguide materials for medical applications.However,the mechanisms underlying the interaction between microstructure and ultrasonic propagation in the alloy remain unclear.Herein,variations in the ultrasonic attenuation behavior of medical extra-low-interstitial-grade Ti6A14V alloys with microstructure evolution are systematically investigated.Experimental results demonstrate that within a d(grain size)/λ(wavelength)range of 0.1-1,scattering attenuation and dislocation damping are the key factors affecting ultrasonic attenuation.Longitudinal-wave scattering attenuation is directly proportional to the grain size,and dislocation damping is primarily influenced by the orientation of α grains.In particular,dislocation slip on the prismatic planes of αgrains is found to be a key factor influencing the dislocation-damping effect for dual-phase Ti alloys.This can be attributed to the oscillatory movement of dislocations in response to ultrasonic-wave disturbance when the wave propagation direction is parallel to the prismatic planes of αgrains,causing energy dissipation.Further,the mechanisms by which dislocation types and movement patterns influence ultrasonic attenuation are discussed in detail based on a G-L dislocation pinning model.
基金support from UKRI/EPSRC(ActionSpec,Grant Ref:EP/X030822/1)Imperial College London for a Dean’s PhD Scholarship.B.T.and A.K.thank the EPSRC for a Programme Grant(EP/W017075/1)funding by the Imperial College London President’s PhD Scholarships.
文摘This study demonstrates that the integration of plasmonic palladium(Pd)nanoparticles between a bismuth vanadate(BVO)coating and an electrode interface can significantly improve solar-driven glycerol oxidation.Pd nanoparticles of controllable shape,size and coverage were produced using a novel aerosol-assisted chemical vapour deposition(AACVD)synthetic route and then coated with BVO using the same technique.The nanoparticles enhanced visible light absorption and crystallinity.At 1.23 VRHE,the photocurrent density of bare BVO increased from 0.62 mA cm^(-2) in the absence of glycerol to 1.20 mA cm^(-2) with 0.5 M glycerol.When Pd nanoparticles were incorporated beneath BVO,the photocurrent further increased from 0.86 mA cm^(-2) without glycerol to 1.58 mA cm^(-2) with 0.5 M glycerol,and the incident photon-to-current conversion efficiency(IPCE)boosted from~15%to~40%at 400 nm.Ultra-fast transient absorption spectroscopy suggests that the addition of Pd nanoparticles introduces additional charge transfer pathways,including hot electron injection and plasmon-coupled states,which prolong carrier lifetimes and suppress recombination.These combined effects provide a promising strategy to improve the efficiency and durability of photoelectrochemical devices for sustainable fuel generation and selective organic oxidation reactions.
基金supported by the King Abdul ah University of Science and Technology(KAUST)office of Research Administration(ORA)under award No:OSR-CCF-3079 and OSR-2016-CRG5-3029the National Research Foundation of Korea(2019R1A6A1A11044070)
文摘The development of high-performance organic solar cells(OSCs)with high operational stability is essential to accelerate their commercialization.Unfortunately,our understanding of the origin of instabilities in state-of-the-art OSCs based on bulk heterojunction(BHJ)featuring non-fullerene acceptors(NFAs)remains limited.Herein,we developed NFA-based OSCs using different charge extraction interlayer materials and studied their storage,thermal,and operational stabilities.Despite the high power conversion efficiency(PCE)of the OSCs(17.54%),we found that cells featuring self-assembled monolayers(SAMs)as hole-extraction interlayers exhibited poor stability.The time required for these OSCs to reach 80%of their initial performance(T_(80))was only 6h under continuous thermal stress at 85℃in a nitrogen atmosphere and 1 h under maximum power point tracking(MPPT)in a vacuum.Inserting MoO_(x)between ITO and SAM enhanced the T_(80)to 50 and~15 h after the thermal and operational stability tests,respectively,while maintaining a PCE of 16.9%.Replacing the organic PDINN electron transport layer with ZnO NPs further enhances the cells'thermal and operational stability,boosting the T_(80)to 1000 and 170 h,respectively.Our work reveals the synergistic roles of charge-selective interlayers and device architecture in developing efficient and stable OSCs.
基金EPSRC project ATIP,Grant/Award Number:EP/TO28513/1China Scholarship Council(CSC)via the CSC Imperial Scholarship。
文摘The power conversion efficiencies(PCEs)of single-junction organic solar cells(OSCs)have surpassed 19%,owing to the emerging Y-series nonfullerene acceptors(NFAs).Undoubtedly,the power and flexibility of chemical design has been a strong driver for this rapid efficiency improvement in the OSC field.Over the course of the past 3 years,a variety of modifications have been made to the structure of the Y6 acceptor,and a large number of Y-series NFAs have been reported to further improve performance.Herein,we present our insights into the rationale behind the Y6 acceptor and discuss the design principles toward high-performance Y-series NFAs.It is clear that structural modifications through choice of heteroatom,soluble chains,πspacers,central cores,and end groups alter the material characteristics and properties,contributing to distinctive photovoltaic performance.Subsequently,we analyze various design strategies of Y-series-containing materials,including polymerized small-molecule acceptors(PSMA),non-fused-ring acceptors(NFRA),and all-fused-ring acceptors(AFRA).This review is expected to be of value in providing effective molecular design strategies for high-performance NFAs in future innovations.
基金support from the European Commission through the Marie Skłodowska-Curie Actions(H2020-MSCA-IF-2020-101018002).
文摘Hot carrier cooling is slowed down upon alloying tin in lead-halide perovskite nanocrystals through the engineering of carrier-phonon and carrier-defect interactions.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2023-00213089)supported by the Technology Innovation Program(Grant No.RS-2022-00154781,Development of large-area wafer-level flexible/stretchable hybrid sensor platform technology for form factor-free highly integrated convergence sensor)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)+1 种基金supported by the MSIT,Korea,under the ITRC(Information Technology Research Center)support program(Grant No.IITP-2023-2020-0-01461)supervised by the IITP(Institute for Information&communications Technology Planning&Evaluation)supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2021K1A4A7A03093851).
文摘Ultra-flexible organic photovoltaics(OPVs)are promising candidates for next-generation power sources owing to their low weight,transparency,and flexibility.However,obtaining ultra-flexibility under extreme repetitive mechanical stress while maintaining optical transparency remains challenging because of the intrinsic brittleness of transparent electrodes.Here,we introduce straindurable ultra-flexible semitransparent OPVs with a thickness below 2μm.The conformal surface coverage of nanoscale thin metal electrodes(<10 nm)is achieved,resulting in extremely low flexural rigidity and high strain durability.In-depth optical and electrical analyses on ultrathin metal electrodes showed that the devices maintain over 73%of their initial efficiency after 1000 cycles of repetitive compression and release at 66%compressive strain,and the average visible light transmittances remain higher than 30%.To our knowledge,this is the first systematical study on mechanical behaviors of strain-durable ultra-flexible ST-OPVs through precise adjustment of each ultrathin electrode thickness toward the emergence of next-generation flexible power sources.
