P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low cost.However,compared to their n-type counterparts,they show relativ...P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low cost.However,compared to their n-type counterparts,they show relatively low TE performance,limiting their application in TE devices.In this work,we simultaneously introduce Bi alloying at Sb sites and Ag doping at Mg sites into the Mg_(3)Sb_(2)to coopera-tively optimize the electrical and thermal properties for the first time,acquiring the highest ZT value of∼0.85 at 723 K and a high average ZT of 0.39 in the temperature range of 323-723 K in sample Mg_(2.94)Ag_(0.06)Sb_(1.9)Bi_(0.1).The first-principle calculations show that the codoping of Ag and Bi can shift the Fermi level into the valence band and narrow the band gap,resulting in the increased carrier concentration from 3.50×10^(17)cm^(-3)in the reference Mg 3 Sb 0.9 Bi 0.1 to∼7.88×10^(19)cm^(-3)in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.As a result,a remarkable power factor of∼778.9μW m^(-1)K^(-2)at 723 K is achieved in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.Meanwhile,a low lattice thermal conductivity of∼0.48 W m^(-1)K^(-1)at 723 K is also obtained with the help of phonon scattering at the distorted lattice,point defects,and nano-precipitates in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.The synergistic effect of using the multi-element co-doping/-alloying to optimize electrical properties in Mg_(3)Sb_(2)holds promise for further improving the TE performance of Zintl phase materials or even others.展开更多
Ni-rich layered oxides(Ni>80%)with high energy density have become a mainstream cathode material for Li-ion batteries.However,irreversible phase transitions and interface instability are deep-seated challenges in c...Ni-rich layered oxides(Ni>80%)with high energy density have become a mainstream cathode material for Li-ion batteries.However,irreversible phase transitions and interface instability are deep-seated challenges in commercializing Ni-rich materials.This study used a collaborative modification strategy involving doping and coating with quadrivalent elements to construct Ni-rich materials.In particular,introducing tetravalent Zr makes the valence change of Ni(2+to 4+)more accessible to complete spontaneously during the charging and discharging processes,which significantly suppresses the cationic mixing and irreversible phase transition(H2?H3).Combining the strategy of constructing CeO_(2) coatings on the surface and interfacial spinel-like phases improves the Li+diffusion kinetics and interfacial stability.Simultaneously,part of the strongly oxidizing four-valence Ce^(4+)diffuses to the surface layer,further increasing the average valence state of Ni.Therefore,LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(NCM)-Zr@Ce achieves 78.5%outstanding retention at1.0C after 200 cycles within 3.0-4.3 V compared to unmodified NCM with 41.4%retention.The improved cyclic stability can be attributed to the collaborative modification strategy of the quadrivalent elements,which provides an effective synergistic modification strategy for developing high-performance Li-ion battery cathode materials.展开更多
The vertical phase distribution of active layers plays a vital role in balancing exciton dissociation and cha rge transport for achieving efficient polymer solar cells(PSCs).The layer-by-layer(LbL)PSCs are commonly pr...The vertical phase distribution of active layers plays a vital role in balancing exciton dissociation and cha rge transport for achieving efficient polymer solar cells(PSCs).The layer-by-layer(LbL)PSCs are commonly prepared by using sequential spin-coating method from donor and acceptor solutions with distinct solvents and solvent additives.The enhanced exciton dissociation is expected in the LbL PSCs with efficient charge transport in the relatively neat donor or acceptor layers.In this work,a series of LbL all-polymer solar cells(APSCs)were fabricated with PM6 as donor and PY-DT as acceptor,and triplet material m-Ir(CPmPB)_(3)is deliberately incorporated into PY-DT layer to prolong exciton lifetimes of active layers.The power conversion efficiency(PCE)of LbL APSCs is improved to 18.24%from 17.32%by incorporating 0.3 wt%m-Ir(CPMPB)_(3)in PY-DT layer,benefiting from the simultaneously enhanced short-circuit current density(Isc)of 25.17 mA cm^(-2)and fill factor(FF)of 74.70%.The enhancement of PCE is attributed to the efficient energy transfer of m-Ir(CPmPB)_(3)to PM6 and PY-DT,resulting in the prolonged exciton lifetime in the active layer and the increased exciton diffusion distance.The efficient energy transfer from m-Ir(CPmPB)_(3)to PM6 and PY-DT layer can be confirmed by the increased photoluminescence(PL)intensity and the prolonged PL lifetime of PM6 and PY-DT in PM6+m-Ir(CPmPB)_(3)and PY-DT+m-Ir(CPmPB)_(3)films.This study indicates that the triplet material as solid additive has great potential in fabricating efficient LbL APSCs by prolonging exciton lifetimes in active layers.展开更多
Nowadays,due to uncontrolled synthesis and lack of more direct and systematic evidences,the photoluminescence origin of“zero-dimensional”Cs4PbI6 remains great controversy and the luminescence cannot be controlled.He...Nowadays,due to uncontrolled synthesis and lack of more direct and systematic evidences,the photoluminescence origin of“zero-dimensional”Cs4PbI6 remains great controversy and the luminescence cannot be controlled.Here we propose a controllable dissolution-recrystallization method to synthesize“emissive”and“non-emissive”Cs4PbI6 nanocrystals(NCs)respectively.Through comparing“emissive”and“non-emissive”Cs4PbI6 NCs,it is clearly proved that the visible emission in“emissive”Cs4PbI6 NCs comes from embedded CsPbI3 quantum dots(QDs).It is found for CsPbI3@Cs4PbI6 nanocomposites,methyl acetate(MeAC)and cyclohexane play an important role in dissolution and recrystallization respectively to obtain Cs4PbI6 matrix and CsPbI3 cores.Benefiting from this two-step method,the as-synthesized CsPbI3@Cs4PbI6 nanocomposites with CsPbI3 QDs uniformly distributed in Cs4PbI6 matrix are bright with photoluminescence quantum yield(PLQY)up to 71.4%and exhibit improved stability than CsPbI3 NCs.Moreover,utilizing its formation mechanism,the size of embedded CsPbI3 QDs can be controlled by reasonable designing the“dissolution”process,so that the luminescence of this CsPbI3@Cs4PbI6 nanocomposites can be adjusted in a wide range from green to red(554–630 nm).Our finding not only provides a novel method for synthesizing tunable“emissive”Cs4PbI6 NCs,but also makes clear the photoluminescence origin of“emissive”Cs4PbI6.展开更多
SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long lifespan.However,the intrinsically high thermal conductivity of Si-based m...SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long lifespan.However,the intrinsically high thermal conductivity of Si-based materials also results in poor TE properties.In this investigation,a zirconia(ZrO_(2))composite strategy was applied to an n-type SiGe alloy,tremendously elevating its TE performance.After mechanical alloying and spark plasma sintering(SPS)processes,the ZrO_(2)induced the formation of nanopores in the SiGe matrix via phosphorus adsorption.Moreover,such increase in porosity enhanced the phonon scattering and dramatically suppressed lattice thermal conductivity,from 2.83 to 1.59 W·m^(-1)·K^(-1)at 873 K.Additionally,reduced phosphorus doping led to an increase in Seebeck coefficients and a relatively minor decrease in electrical conductivity,The power factor didn't deteriorate significantly,either,as its maximum of~3.43 mW·m^(-1-)K^(-2)was achieved at 873 K with(Si_(0.8)Ge_(0.2))_(0.097)P_(0.03)(ZrO_(2))_(0.003).In short,a peak figure of merit(ZT)of~1.27 at 873 K and an average ZT~0.7 from 323 to 873 K were obtained.This study demonstrates that the electrical and thermal transportation of SiGe material can be synergistically tuned by compositing ZrO_(2),illustrating a novel strategy to optimize the TE properties of bulk materials.展开更多
L1_(2)phase-strengthened Fe-Co-Ni-based high-entropy alloys(HEAs)have attracted considerable attention due to their excellent mechanical properties.Improving the properties of HEAs through conventional experimental me...L1_(2)phase-strengthened Fe-Co-Ni-based high-entropy alloys(HEAs)have attracted considerable attention due to their excellent mechanical properties.Improving the properties of HEAs through conventional experimental methods is costly.Therefore,a new method is needed to predict the properties of alloys quickly and accurately.In this study,a comprehensive prediction model for L1_(2)phase-strengthened Fe-Co-Ni-based HEAs was developed.The existence of the L1_(2)phase in the HEAs was first predicted.A link was then established between the microstructure(L1_(2)phase volume fraction)and properties(hardness)of HEAs,and comprehensive prediction was performed.Finally,two mutually exclusive properties(strength and plasticity)of HEAs were coupled and co-optimized.The Shapley additive explained algorithm was also used to interpret the contribution of each model feature to the comprehensive properties of HEAs.The vast compositional and process search space of HEAs was progressively screened in three stages by applying different prediction models.Finally,four HEAs were screened from hundreds of thousands of possible candidate groups,and the prediction results were verified by experiments.In this work,L1_(2)phase-strengthened Fe-Co-Ni-based HEAs with high strength and plasticity were successfully designed.The new method presented herein has a great cost advantage over traditional experimental methods.It is also expected to be applied in the design of HEAs with various excellent properties or to explore the potential factors affecting the microstructure/properties of alloys.展开更多
SiGe is recognised as an excellent thermoelectric material with superior mechanical properties and thermal stability in regions with high temperatures.This study explores a novel strategy for coregulating thermoelectr...SiGe is recognised as an excellent thermoelectric material with superior mechanical properties and thermal stability in regions with high temperatures.This study explores a novel strategy for coregulating thermoelectric transport parameters to achieve high thermoelectric properties of p-type SiGe in the mid-temperature region by incorporating nano-TaC into SiGe combined ball milling with spark plasma sintering.By optimizing the amount of TaC in the SiGe matrix,the power factors were significantly increased due to the modulation doping effect based on the work function matching of SiGe with TaC.Simultaneously,the ensemble effect of the nanostructure leads to a significant decrease in thermal conductivity.Thus,a high ZT of 1.06 was accomplished at 873 K,which is 64%higher than that of typical radioisotope thermoelectric generator.Our research offers a novel strategy for expanding and enhancing the thermoelectric properties of SiGe materials in the medium temperature range.展开更多
Tungsten trioxide(WO_(3))has been widely regarded as a prospective bifunctional material due to its electrochromic and pseudocapacitive properties,while still facing the dilemma of inadequate cycle stability and trapp...Tungsten trioxide(WO_(3))has been widely regarded as a prospective bifunctional material due to its electrochromic and pseudocapacitive properties,while still facing the dilemma of inadequate cycle stability and trapping-induced degradation.Here,inspired by the trees-strengthening approach,a unique titanium dioxide(TiO_(2))nanorod arrays strengthened WO_(3)nano-trees(TWNTs)heterojunction was rationally designed and constructed.In sharp contrast to the transmittance modulation(ΔT)attenuation of primary WO_(3)nano-trees during cycling,the TWNTs film showed not only excellent electrochromic performance but also fascinating cycle stability(77.35%retention of the initialΔT after 10,000 cycles).Besides,the trapping-induced degradation could be easily rejuvenated by a potentiostatic de-trapping process.An electrochromic energy storage device(EESD)was further assembled based on the TWNTs film to deliver excellentΔT(up to 79.5%at 633 nm),fast switching speed(tc/tb=1.9 s/14.8 s),extremely high coloration efficiency value(443.4 cm^(2)·C^(−1)),and long-term cycle stability(over 10,000 charge/discharge cycles).This innovative study provided in-depth insights into the electrochromism nature and a significant step in the realization of stable electrochromic-energy storage application,paving the way for multifunctional smart windows as well as next-generation optoelectronic devices.展开更多
In this work,eight Mn-RE(RE=Ce,Pr,Sm,Tb,Er,Tm,Lu,and Y)binary systems were reassessed thermodynamically by the CALPHAD method based on the reported optimizations and experimental information.Self-consistent thermodyna...In this work,eight Mn-RE(RE=Ce,Pr,Sm,Tb,Er,Tm,Lu,and Y)binary systems were reassessed thermodynamically by the CALPHAD method based on the reported optimizations and experimental information.Self-consistent thermodynamic parameters to describe Gibbs energies of various phases in eight Mn-RE binary systems were obtained.The calculated phase equilibria and thermodynamic properties of eight Mn-RE binary systems are in good accor-dance with the experimental results.Furthermore,phase equilibria and ther-modynamic properties of 13 Mn-RE(RE=La,Ce,Pr,Nd,Sm,Gd,Tb,Dy,Ho,Er,Tm,Lu,and Y)binary systems were discussed systematically in combination with the present calculations and the reported optimizations.A trend was found for the variation of phase equilibria and thermodynamic properties of the Mn-RE binary systems.In general,as the RE atomic number increases,the enthalpies of mixing of liquid alloys as well as the enthalpies of formation of the intermetallic compounds become increasingly negative,and the formation temperatures of the intermetallic compounds become higher.The results provide a complete set of self-consistent thermodynamic parameters for the Mn-RE binary systems,and a thermodynamic database of 13 Mn-RE binary systems was finally achieved.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A2054,52273285,52061009,52262032)the National Key Research and Development Program of China(No.2022YFE0119100)the Guangxi Science and Technology Planning Project(Grant No.AD21220056).
文摘P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low cost.However,compared to their n-type counterparts,they show relatively low TE performance,limiting their application in TE devices.In this work,we simultaneously introduce Bi alloying at Sb sites and Ag doping at Mg sites into the Mg_(3)Sb_(2)to coopera-tively optimize the electrical and thermal properties for the first time,acquiring the highest ZT value of∼0.85 at 723 K and a high average ZT of 0.39 in the temperature range of 323-723 K in sample Mg_(2.94)Ag_(0.06)Sb_(1.9)Bi_(0.1).The first-principle calculations show that the codoping of Ag and Bi can shift the Fermi level into the valence band and narrow the band gap,resulting in the increased carrier concentration from 3.50×10^(17)cm^(-3)in the reference Mg 3 Sb 0.9 Bi 0.1 to∼7.88×10^(19)cm^(-3)in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.As a result,a remarkable power factor of∼778.9μW m^(-1)K^(-2)at 723 K is achieved in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.Meanwhile,a low lattice thermal conductivity of∼0.48 W m^(-1)K^(-1)at 723 K is also obtained with the help of phonon scattering at the distorted lattice,point defects,and nano-precipitates in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.The synergistic effect of using the multi-element co-doping/-alloying to optimize electrical properties in Mg_(3)Sb_(2)holds promise for further improving the TE performance of Zintl phase materials or even others.
基金financially supported by the Department of Science and Technology of Guangxi Province (Nos.2022JBGS004,AB21220027,AD19110090 and AD19110077)the National Natural Science Foundation of China (Nos.21805055 and12172096)+2 种基金Guangxi Natural Science Foundation (Nos.2020GXNSFAA159059 and 2020GXNSFAA159037)Guangxi Key Laboratory of Manufacturing Systems Foundation (No.20-065-40-005Z)the Engineering Research Center Foundation of Electronic Information Materials and Devices (No.EIMD-AA202005)。
文摘Ni-rich layered oxides(Ni>80%)with high energy density have become a mainstream cathode material for Li-ion batteries.However,irreversible phase transitions and interface instability are deep-seated challenges in commercializing Ni-rich materials.This study used a collaborative modification strategy involving doping and coating with quadrivalent elements to construct Ni-rich materials.In particular,introducing tetravalent Zr makes the valence change of Ni(2+to 4+)more accessible to complete spontaneously during the charging and discharging processes,which significantly suppresses the cationic mixing and irreversible phase transition(H2?H3).Combining the strategy of constructing CeO_(2) coatings on the surface and interfacial spinel-like phases improves the Li+diffusion kinetics and interfacial stability.Simultaneously,part of the strongly oxidizing four-valence Ce^(4+)diffuses to the surface layer,further increasing the average valence state of Ni.Therefore,LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(NCM)-Zr@Ce achieves 78.5%outstanding retention at1.0C after 200 cycles within 3.0-4.3 V compared to unmodified NCM with 41.4%retention.The improved cyclic stability can be attributed to the collaborative modification strategy of the quadrivalent elements,which provides an effective synergistic modification strategy for developing high-performance Li-ion battery cathode materials.
基金supported by Beijing Natural Science Foundation(4232073 and 1232029)the National Natural Science Foundation of China(62175011,62105017,62205276,and 5231101105)+4 种基金the Natural Science Foundation of Hebei Province(F2023105002)the National Research Foundation of Korea(2023K2A9A2A06059546)the support from the Hong Kong Research Grants Council(PolyU 15307321)RGC Senior Research Fellowship Scheme(SRFS2021–5S01)Research Institute for Smart Energy(CDAQ)。
文摘The vertical phase distribution of active layers plays a vital role in balancing exciton dissociation and cha rge transport for achieving efficient polymer solar cells(PSCs).The layer-by-layer(LbL)PSCs are commonly prepared by using sequential spin-coating method from donor and acceptor solutions with distinct solvents and solvent additives.The enhanced exciton dissociation is expected in the LbL PSCs with efficient charge transport in the relatively neat donor or acceptor layers.In this work,a series of LbL all-polymer solar cells(APSCs)were fabricated with PM6 as donor and PY-DT as acceptor,and triplet material m-Ir(CPmPB)_(3)is deliberately incorporated into PY-DT layer to prolong exciton lifetimes of active layers.The power conversion efficiency(PCE)of LbL APSCs is improved to 18.24%from 17.32%by incorporating 0.3 wt%m-Ir(CPMPB)_(3)in PY-DT layer,benefiting from the simultaneously enhanced short-circuit current density(Isc)of 25.17 mA cm^(-2)and fill factor(FF)of 74.70%.The enhancement of PCE is attributed to the efficient energy transfer of m-Ir(CPmPB)_(3)to PM6 and PY-DT,resulting in the prolonged exciton lifetime in the active layer and the increased exciton diffusion distance.The efficient energy transfer from m-Ir(CPmPB)_(3)to PM6 and PY-DT layer can be confirmed by the increased photoluminescence(PL)intensity and the prolonged PL lifetime of PM6 and PY-DT in PM6+m-Ir(CPmPB)_(3)and PY-DT+m-Ir(CPmPB)_(3)films.This study indicates that the triplet material as solid additive has great potential in fabricating efficient LbL APSCs by prolonging exciton lifetimes in active layers.
基金This work was financially supported by the Joint Funds of the National Natural Science Foundation of China and Yunnan Province(No.U1902222)the National Natural Science Foundation of China(Nos.51961145101 and 52102195)+3 种基金China Postdoctoral Science Foundation(Nos.2020M672960 and 2021M703656)Guangzhou Science&Technology Project(No.202007020005)Hunan High Level Talent Gathering Project(Nos.2019RS1077 and 2020RC5007)the Guangdong Provincial Key Laboratory of Semiconductor Micro Display(No.2020B121202003)。
文摘Nowadays,due to uncontrolled synthesis and lack of more direct and systematic evidences,the photoluminescence origin of“zero-dimensional”Cs4PbI6 remains great controversy and the luminescence cannot be controlled.Here we propose a controllable dissolution-recrystallization method to synthesize“emissive”and“non-emissive”Cs4PbI6 nanocrystals(NCs)respectively.Through comparing“emissive”and“non-emissive”Cs4PbI6 NCs,it is clearly proved that the visible emission in“emissive”Cs4PbI6 NCs comes from embedded CsPbI3 quantum dots(QDs).It is found for CsPbI3@Cs4PbI6 nanocomposites,methyl acetate(MeAC)and cyclohexane play an important role in dissolution and recrystallization respectively to obtain Cs4PbI6 matrix and CsPbI3 cores.Benefiting from this two-step method,the as-synthesized CsPbI3@Cs4PbI6 nanocomposites with CsPbI3 QDs uniformly distributed in Cs4PbI6 matrix are bright with photoluminescence quantum yield(PLQY)up to 71.4%and exhibit improved stability than CsPbI3 NCs.Moreover,utilizing its formation mechanism,the size of embedded CsPbI3 QDs can be controlled by reasonable designing the“dissolution”process,so that the luminescence of this CsPbI3@Cs4PbI6 nanocomposites can be adjusted in a wide range from green to red(554–630 nm).Our finding not only provides a novel method for synthesizing tunable“emissive”Cs4PbI6 NCs,but also makes clear the photoluminescence origin of“emissive”Cs4PbI6.
基金financially supported by the National Key Research and Development Program of China(Nos.2022YFE0119100 and 2017YFE0198000)the National Natural Science Foundation of China(Nos.U21A2054,52273285,52061009 and 52262032)Guangxi Science and Technology Planning Project(No.AD21220056)。
文摘SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long lifespan.However,the intrinsically high thermal conductivity of Si-based materials also results in poor TE properties.In this investigation,a zirconia(ZrO_(2))composite strategy was applied to an n-type SiGe alloy,tremendously elevating its TE performance.After mechanical alloying and spark plasma sintering(SPS)processes,the ZrO_(2)induced the formation of nanopores in the SiGe matrix via phosphorus adsorption.Moreover,such increase in porosity enhanced the phonon scattering and dramatically suppressed lattice thermal conductivity,from 2.83 to 1.59 W·m^(-1)·K^(-1)at 873 K.Additionally,reduced phosphorus doping led to an increase in Seebeck coefficients and a relatively minor decrease in electrical conductivity,The power factor didn't deteriorate significantly,either,as its maximum of~3.43 mW·m^(-1-)K^(-2)was achieved at 873 K with(Si_(0.8)Ge_(0.2))_(0.097)P_(0.03)(ZrO_(2))_(0.003).In short,a peak figure of merit(ZT)of~1.27 at 873 K and an average ZT~0.7 from 323 to 873 K were obtained.This study demonstrates that the electrical and thermal transportation of SiGe material can be synergistically tuned by compositing ZrO_(2),illustrating a novel strategy to optimize the TE properties of bulk materials.
基金supported by the National Natural Science Foundation of China(Nos.52161011,52373236)the Natural Science Foundation of Guangxi Province(2023GXNSFDA026046)+8 种基金Guangxi Science and Technology Project(Guike AB24010247)the Central Guiding Local Science and Technology Development Fund Projects(Guike ZY23055005)the Scientific Research and Technology Development Program of Guilin(20220110-3)the Scientific Research and Technology Development Program of Nanning Jiangnan district(20230715-02)the Guangxi Key Laboratory of Superhard Material(2022-K-001),the Guangxi Key Laboratory of Information Materials(231003-Z,231013-Z and 231033-K)the Engineering Research Center of Electronic Information Materials and Devices,the Ministry of Education(EIMD-AB202009),the Major Research Plan of the National Natural Science Foundation of China(92166112),the Innovation Project of GUET Graduate Education(2022YCXS200)the Projects of MOE Key Lab of Disaster Forecast and Control in Engineering in Jinan University(20200904006)the Guangdong Province International Science and Technology Cooperation Project(2023A0505050103)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF010)for the financial support given to this work.
文摘L1_(2)phase-strengthened Fe-Co-Ni-based high-entropy alloys(HEAs)have attracted considerable attention due to their excellent mechanical properties.Improving the properties of HEAs through conventional experimental methods is costly.Therefore,a new method is needed to predict the properties of alloys quickly and accurately.In this study,a comprehensive prediction model for L1_(2)phase-strengthened Fe-Co-Ni-based HEAs was developed.The existence of the L1_(2)phase in the HEAs was first predicted.A link was then established between the microstructure(L1_(2)phase volume fraction)and properties(hardness)of HEAs,and comprehensive prediction was performed.Finally,two mutually exclusive properties(strength and plasticity)of HEAs were coupled and co-optimized.The Shapley additive explained algorithm was also used to interpret the contribution of each model feature to the comprehensive properties of HEAs.The vast compositional and process search space of HEAs was progressively screened in three stages by applying different prediction models.Finally,four HEAs were screened from hundreds of thousands of possible candidate groups,and the prediction results were verified by experiments.In this work,L1_(2)phase-strengthened Fe-Co-Ni-based HEAs with high strength and plasticity were successfully designed.The new method presented herein has a great cost advantage over traditional experimental methods.It is also expected to be applied in the design of HEAs with various excellent properties or to explore the potential factors affecting the microstructure/properties of alloys.
基金supported by the National Natural Science Foundation of China(52173094 and 52003062)Guangxi Natural Science Foundation of China(2019GXNSFFA245010)the Scientific and Technological Plan of Guilin City(20220110-1).
基金supported by National Key Research and Development Program of China(No.2017YFE0198000,2022YFE0119100).National Natural Science Foundation of China(Grant No.U21A2054,52273285,52061009,52262032).Guangxi Science and Technology Project(Grant No.AD21220056).
文摘SiGe is recognised as an excellent thermoelectric material with superior mechanical properties and thermal stability in regions with high temperatures.This study explores a novel strategy for coregulating thermoelectric transport parameters to achieve high thermoelectric properties of p-type SiGe in the mid-temperature region by incorporating nano-TaC into SiGe combined ball milling with spark plasma sintering.By optimizing the amount of TaC in the SiGe matrix,the power factors were significantly increased due to the modulation doping effect based on the work function matching of SiGe with TaC.Simultaneously,the ensemble effect of the nanostructure leads to a significant decrease in thermal conductivity.Thus,a high ZT of 1.06 was accomplished at 873 K,which is 64%higher than that of typical radioisotope thermoelectric generator.Our research offers a novel strategy for expanding and enhancing the thermoelectric properties of SiGe materials in the medium temperature range.
基金supported by Scientific Research and Technology Development Program of Guangxi(No.ZY21195037)Dongguan Social Science and Technology Development Key Project(No.20221800905142)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2019A1515111048)Doctoral Start Up Fund of Dongguan University of Technology(No.GC300501-078)Guangxi Key Laboratory of Information Materials(Guilin University of Electronic Technology,China)(No.211013-K),and Guangdong Provincial Key Laboratory of Distributed Energy Systems(No.2020B1212060075).
文摘Tungsten trioxide(WO_(3))has been widely regarded as a prospective bifunctional material due to its electrochromic and pseudocapacitive properties,while still facing the dilemma of inadequate cycle stability and trapping-induced degradation.Here,inspired by the trees-strengthening approach,a unique titanium dioxide(TiO_(2))nanorod arrays strengthened WO_(3)nano-trees(TWNTs)heterojunction was rationally designed and constructed.In sharp contrast to the transmittance modulation(ΔT)attenuation of primary WO_(3)nano-trees during cycling,the TWNTs film showed not only excellent electrochromic performance but also fascinating cycle stability(77.35%retention of the initialΔT after 10,000 cycles).Besides,the trapping-induced degradation could be easily rejuvenated by a potentiostatic de-trapping process.An electrochromic energy storage device(EESD)was further assembled based on the TWNTs film to deliver excellentΔT(up to 79.5%at 633 nm),fast switching speed(tc/tb=1.9 s/14.8 s),extremely high coloration efficiency value(443.4 cm^(2)·C^(−1)),and long-term cycle stability(over 10,000 charge/discharge cycles).This innovative study provided in-depth insights into the electrochromism nature and a significant step in the realization of stable electrochromic-energy storage application,paving the way for multifunctional smart windows as well as next-generation optoelectronic devices.
基金supported by the Natural Science Foundation of Guangxi(2021GXNSFBA075026 and 2019GXNSFGA245005)the Fund of Guangxi Key Laboratory of Information Materials(221028-Z)+1 种基金Guo R acknowledges the support of the Innovation Project of Guilin University of Electronic Technology(GUET)for Graduate Education(2023YCXS150)Zhang S would like to thank Guangxi Training Program of Innovation and Entrepreneurship for Undergraduates(S202210595268)for its support.
文摘基于m-TiO_(2)/m-ZrO_(2)/C的无空穴可印刷介观钙钛矿太阳能电池(p-MPSCs)具有成本低廉、操作简便和稳定性优异的特点,被认为是最具商业应用潜力的新型光伏器件之一.然而,与传统PSC相比,p-MPSCs的开路电压(VOC)损失较大,导致能量转换效率(PCE)与传统PSC存在差距.在此,我们提出了一种利用5-氨基-4甲酰胺咪唑盐酸盐(AICA)提升p-MPSCs开路电压的方法.AICA不仅可以调节钙钛矿膜的功函数,其酰胺基团和氨基还能分别钝化钙钛矿中未配位的Pb2+和I−缺陷,稳定钙钛矿的结构,形成高质量钙钛矿薄膜,从而抑制缺陷诱导的非辐射复合.因此,引入AICA后p-MPSCs获得了16.68%的PCE,并且VOC从0.88提升至0.98 V.
基金supported financially by Guangxi Natural Science Foundation(2020GXNSFFA297004)National Natural Science Foundation of China(51971069,51461013,51761008)+1 种基金Guangxi Key Laboratory of Information Materials(211007-Z)Engineering Research Center of Electronic Information Materials and Devices(EIMDAA202004)。
文摘In this work,eight Mn-RE(RE=Ce,Pr,Sm,Tb,Er,Tm,Lu,and Y)binary systems were reassessed thermodynamically by the CALPHAD method based on the reported optimizations and experimental information.Self-consistent thermodynamic parameters to describe Gibbs energies of various phases in eight Mn-RE binary systems were obtained.The calculated phase equilibria and thermodynamic properties of eight Mn-RE binary systems are in good accor-dance with the experimental results.Furthermore,phase equilibria and ther-modynamic properties of 13 Mn-RE(RE=La,Ce,Pr,Nd,Sm,Gd,Tb,Dy,Ho,Er,Tm,Lu,and Y)binary systems were discussed systematically in combination with the present calculations and the reported optimizations.A trend was found for the variation of phase equilibria and thermodynamic properties of the Mn-RE binary systems.In general,as the RE atomic number increases,the enthalpies of mixing of liquid alloys as well as the enthalpies of formation of the intermetallic compounds become increasingly negative,and the formation temperatures of the intermetallic compounds become higher.The results provide a complete set of self-consistent thermodynamic parameters for the Mn-RE binary systems,and a thermodynamic database of 13 Mn-RE binary systems was finally achieved.
