Fairness is a fundamental value in human societies,with individuals concerned about unfairness both to themselves and to others.Nevertheless,an enduring debate focuses on whether self-unfairness and other-unfairness e...Fairness is a fundamental value in human societies,with individuals concerned about unfairness both to themselves and to others.Nevertheless,an enduring debate focuses on whether self-unfairness and other-unfairness elicit shared or distinct neuropsychological processes.To address this,we combined a three-person ultimatum game with computational modeling and advanced neuroimaging analysis techniques to unravel the behavioral,cognitive,and neural patterns underlying unfairness to self and others.Our behavioral and computational results reveal a heightened concern among participants for self-unfairness over other-unfairness.Moreover,self-unfairness consistently activates brain regions such as the anterior insula,dorsal anterior cingulate cortex,and dorsolateral prefrontal cortex,spanning various spatial scales that encompass univariate activation,local multivariate patterns,and whole-brain multivariate patterns.These regions are well-established in their association with emotional and cognitive processes relevant to fairness-based decision-making.Conversely,other-unfairness primarily engages the middle occipital gyrus.Collectively,our findings robustly support distinct neurocomputational signatures between self-unfairness and other-unfairness.展开更多
The distinguished electronic and optical properties of lead halide perovskites(LHPs)make them good candidates for active layer in optoelectronic devices.Integrating LHPs and two-dimensional(2 D)transition metal dichal...The distinguished electronic and optical properties of lead halide perovskites(LHPs)make them good candidates for active layer in optoelectronic devices.Integrating LHPs and two-dimensional(2 D)transition metal dichalcogenides(TMDs)provides opportunities for achieving increased performance in heterostructured LHPs/TMDs based optoelectronic devices.The electronic structures of LHPs/TMDs heterostructures,such as the band offsets and interfacial interaction,are of fundamental and technological interest.Here CsPbBr3 and MoSe2 are taken as prototypes of LHPs and 2 D TMDs to investigate the band alignment and interfacial coupling between them.Our GGA-PBE and HSE06 calculations reveal an intrinsic type-II band alignment between CsPbBr3 and MoSe2.This type-II band alignment suggests that the performance of CsPbBr3-based photodetectors can be improved by incorporating MoSe2 monolayer.Furthermore,the absence of deep defect states at CsPbBr3/MoSe2 interfaces is also beneficial to the better performance of photodetectors based on CsPbBr3/MoSe2 heterostructure.This work not only offers insights into the improved performance of photodetectors based on LHPs/TMDs heterostructures but it also provides guidelines for designing high-efficiency optoelectronic devices based on LHPs/TMDs heterostructures.展开更多
With the formation of structural vacancies,zirconium nitrides(key materials for cutting coatings,super wearresistance,and thermal barrier coatings) display a variety of compositions and phases featuring both cation an...With the formation of structural vacancies,zirconium nitrides(key materials for cutting coatings,super wearresistance,and thermal barrier coatings) display a variety of compositions and phases featuring both cation and nitrogen enrichment.This study presents a systematic exploration of the stable crystal structures of zirconium heminitride combining the evolutionary algorithm method and ab initio density functional theory calculations at pressures of 0 GPa,30 GPa,60 GPa,90 GPa,120 GPa,150 GPa,and 200 GPa.In addition to the previously proposed phases P42/mnm-,Pnnn-,and Cmcm-Zr2 N,five new high-pressure Zr_(2)N phases of PA/nmm,IA/mcm,P2_(1)/m,P3 m1,and C2/m are discovered.An enthalpy study of these candidate configurations reveals various structural phase transformations of Zr2 N under pressure.By calculating the elastic constants and phonon dispersion,the mechanical and dynamical stabilities of all predicted structures are examined at ambient and high pressures.To understand the structure-property relationships,the mechanical properties of all Zr_(2)N compounds are investigated,including the elastic moduli,Vickers hardness,and directional dependence of Young’s modulus.The Cmncm-Zr2 N phase is found to belong to the brittle materials and has the highest Vickers hardness(12.9 GPa) among all candidate phases,while the I4/mcm-Zr2 N phase is the most ductile and has the lowest Vickers hardness(2.1 GPa).Furthermore,the electronic mechanism underlying the diverse mechanical behaviors of Zr2 N structures is discussed by analyzing the partial density of states.展开更多
The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise...The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise to strong anharmonicities and low lattice thermal conductivities.The double anions with distinctly different electronegativities of Mo_(2)AB_(2)monolayers can reduce the correlation between electron transport and phonon scattering,and further benefit much to their good thermoelectric properties.Thermoelectric properties of these Mo_(2)AB_(2)monolayers exhibit obvious anisotropies due to the direction-dependent chemical bondings and transport properties.Furthermore,their thermoelectric properties strongly depend on carrier type(n-type or p-type),carrier concentration and temperature.It is found that n-type Mo_(2)AB_(2)monolayers can be excellent thermoelectric materials with high electric conductivity,σ,and figures of merit,ZT.Choosing the types of A and B anions of Mo_(2)AB_(2)is an effective strategy to optimize their thermoelectric performance.These results provide rigorous understanding on thermoelectric properties of double-anions compounds and important guidance for achieving high thermoelectric performance in multi-anion compounds.展开更多
The study of boron structure is fascinating because boron has various allotropes containing boron icosahedrons under pressure. Here, we propose a new boron structure(space group Fm3m) that is dynamically stable at 1.4...The study of boron structure is fascinating because boron has various allotropes containing boron icosahedrons under pressure. Here, we propose a new boron structure(space group Fm3m) that is dynamically stable at 1.4 tera-Pascal(TPa)using density functional theory and an evolutionary algorithm. The unit cell of this structure can be viewed as a structure with a boron atom embedded in the icosahedron. This structure behaves as a metal, and cannot be stable under ambient pressure. Furthermore, we found electrons gather in lattice interstices, which is similar to that of the semiconductor Na or Ca_(2)N-Ⅱ under high pressure. The discovery of this new structure expands our comprehension of high-pressure condensed matter and contributes to the further development of high-pressure science.展开更多
The site occupancy behavior of ternary alloying elements inγ'-Ni3Al(a key strengthening phase of commercial Ni-based single-crystal superalloys)can change with temperature and alloy composition owing to the effec...The site occupancy behavior of ternary alloying elements inγ'-Ni3Al(a key strengthening phase of commercial Ni-based single-crystal superalloys)can change with temperature and alloy composition owing to the effect of entropy.Using a total-energy method based on density functional theory,the dependence of tensile and shear behaviors on the site preference of alloying elements inγ'-Ni3Al were investigated in detail.Our results demonstrate that Fe,Ru,and Ir can significantly improve the ideal tensile and shear strength of theγ'phase when occupying the Al site,with Ru resulting in the strongest enhancement.In contrast,elements with fully filled d orbitals(i.e.,Cu,Zn,Ag,and Cd)are expected to reduce the ideal tensile and shear strength.The calculated stress-strain relationships of Ni3Al alloys indicate that none of the alloying elements can simultaneously increase the ideal strength of theγ'phase for both Ni1-site and Ni2-site substitutions.In addition,the charge redistribution and the bond length of the alloying elements and host atoms during the tensile and shear processes are analyzed to unveil the underlying electronic mechanisms.展开更多
2D-material-based photodetectors enhanced by plasmonic nanostructures can support responsivity/detectivity several orders higher than commercial photodetectors,drawing extensive attention as promising candidates for t...2D-material-based photodetectors enhanced by plasmonic nanostructures can support responsivity/detectivity several orders higher than commercial photodetectors,drawing extensive attention as promising candidates for the next-generation photodetectors.However,to boost the nanostructure-enhanced 2D photodetectors into real-world applications,crucial challenges lie in the design of broadband enhancing nanostructures and their scalable and position-controllable fabrication.Here,based on a broadband resonant plasmonic disk array fabricated by a scalable and position-controllable technique(direct writing photolithography),we present a visible-near infrared(405-1310 nm)2D WS_(2) photodetector,whose detectivity is up to 3.9×10^(14)Jones,a value exceeding that of the previous plasmon-enhanced 2D photodetectors.The broadened spectral response range and the high detectivity originate from the hot electron injection,optical absorption enhancement,and strain effect supported by the plasmonic array.Furthermore,the designed plasmonic 2D photodetector supports self-powered photodetection,indicating promising potential in energy-free and portable optoelectronic systems.Our results demonstrate an effective method to construct high-performance broadband photodetectors,which can facilitate the development of 2D photodetectors in commercial applications.展开更多
With advantages of low costs and high energy density,Li–S batteries are considered as one of the most promising energy storage devices.However,Li_(2)S_(2) with a high dissociation energy and insulative properties is ...With advantages of low costs and high energy density,Li–S batteries are considered as one of the most promising energy storage devices.However,Li_(2)S_(2) with a high dissociation energy and insulative properties is hard to convert into Li_(2)S,resulting in underutilization of sulfur capacity.Herein,Co-Mo_(2)C@C yolk–shell spheres as nanoreactors were designed to confront this challenge rationally.The Co-Mo_(2)C@C-induced Li_(2)S_(1/2) nucleation and growth in the three-dimensional process and the cathode produced more Li_(2)S after full discharge.Experimental studies and theoretical calculations reveal that the conversion barrier from Li_(2)S_(2) into Li_(2)S was lowered while the diffusion of lithium ions and electron transfer accelerated when using the Co-Mo_(2)C@C catalyst.Based on the above advantages,the Co-Mo_(2)C@C/S cathode exhibits a high reversible capacity and excellent cyclic stability,such as an initial specific capacity of 1200 mAh g^(−1) at 0.1 C with 709 mAh g^(−1) at 1.0 C after 1000 cycles with a low capacity fading rate of 0.04%per cycle.Even at high densities of 3.0 C and 5.0 C,the specific capacities are 647.6 and 557.7 mAh g^(−1) after 400 cycles,respectively.Impressively,it also shows ca.770 and 900 mAh g^(−1) at 0.2 C after 50 cycles with high sulfur loadings of 4.2 and 5.1 mg cm−2,respectively.The present work may provide new insights into the design of nanoreactors to promote Li_(2)S_(1/2) growth in a three-dimensional process and accelerate conversion from solid Li_(2)S_(2) to solid Li_(2)S in high performance Li–S batteries.展开更多
Recent years have seen swift increase in the power conversion efficiency of perovskite solar cells(PSCs)Interface engineering is a promising route for further improving the performance of PSCs.Here we perform firstpri...Recent years have seen swift increase in the power conversion efficiency of perovskite solar cells(PSCs)Interface engineering is a promising route for further improving the performance of PSCs.Here we perform firstprinciples calculations to explore the effect of four candidate buffer materials(MACl,MAI,PbCl2and PbI2)on the electronic structures of the interface between MAPbI3absorber and TiO2.We find that MAX(X=Cl,I)as buffer layers will introduce a high electron barrier and enhance the electronhole recombination.Additionally,MAX does not passivate the surface states well.The conduction band minimum of PbI2is much lower than that of MAPbI3absorber,which significantly limits the band bending of the absorber and open-circuit voltage of solar cells.On the other side,suitable bandedge energy level positions,small lattice mismatch with TiO2surfaces,and excellent surface passivation make PbCl2a promising buffer material for absorber/electron-transport-layer interface engineering in PSCs.Our results in this work thus provide deep understanding on the effects of interface engineering with a buffer layer,which shall be useful for improving the performance of PSCs and related optoelectronics.展开更多
Ternary compounds with an immiscible pair of elements are relatively unexplored but promising for novel quantum materials discovery.Exploring what third element and its ratio that can be added to make stable ternary c...Ternary compounds with an immiscible pair of elements are relatively unexplored but promising for novel quantum materials discovery.Exploring what third element and its ratio that can be added to make stable ternary compounds out of an immiscible pair of elements remains a great challenge.In this work,we combine a machine learning(ML)method with ab initio calculations to efficiently search for the energetically favorable ternary La-Co-Pb compounds containing immiscible elements Co and Pb.Three previously reported structures are correctly captured by our approach.Moreover,we predict a ground state La_(3)CoPb compound and 57 low-energy La-Co-Pb ternary compounds.Attempts to synthesize La_(3)CoPb via multiple techniques produce mixed or multi-phases samples with,at best,ambiguous signals of the predicted lowest-energy La_(3)CoPb and the second lowest-energy La_(18)Co_(28)Pb_(3)phases.The calculated results of Gibbs free energy are consistent with experiments,and will provide very useful guidance for further experimental synthesis.展开更多
基金supported by the National Natural Science Foundation of China (32271126 and 31920103009)the Natural Science Foundation of Guangdong Province (2021A1515010746)+1 种基金the Major Project of National Social Science Foundation (20&ZD153)Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions (2023SHIBS0003).
文摘Fairness is a fundamental value in human societies,with individuals concerned about unfairness both to themselves and to others.Nevertheless,an enduring debate focuses on whether self-unfairness and other-unfairness elicit shared or distinct neuropsychological processes.To address this,we combined a three-person ultimatum game with computational modeling and advanced neuroimaging analysis techniques to unravel the behavioral,cognitive,and neural patterns underlying unfairness to self and others.Our behavioral and computational results reveal a heightened concern among participants for self-unfairness over other-unfairness.Moreover,self-unfairness consistently activates brain regions such as the anterior insula,dorsal anterior cingulate cortex,and dorsolateral prefrontal cortex,spanning various spatial scales that encompass univariate activation,local multivariate patterns,and whole-brain multivariate patterns.These regions are well-established in their association with emotional and cognitive processes relevant to fairness-based decision-making.Conversely,other-unfairness primarily engages the middle occipital gyrus.Collectively,our findings robustly support distinct neurocomputational signatures between self-unfairness and other-unfairness.
基金financially supported by the National Natural Science Foundation of China(Grants No.11804058,11674310,61622406).
文摘The distinguished electronic and optical properties of lead halide perovskites(LHPs)make them good candidates for active layer in optoelectronic devices.Integrating LHPs and two-dimensional(2 D)transition metal dichalcogenides(TMDs)provides opportunities for achieving increased performance in heterostructured LHPs/TMDs based optoelectronic devices.The electronic structures of LHPs/TMDs heterostructures,such as the band offsets and interfacial interaction,are of fundamental and technological interest.Here CsPbBr3 and MoSe2 are taken as prototypes of LHPs and 2 D TMDs to investigate the band alignment and interfacial coupling between them.Our GGA-PBE and HSE06 calculations reveal an intrinsic type-II band alignment between CsPbBr3 and MoSe2.This type-II band alignment suggests that the performance of CsPbBr3-based photodetectors can be improved by incorporating MoSe2 monolayer.Furthermore,the absence of deep defect states at CsPbBr3/MoSe2 interfaces is also beneficial to the better performance of photodetectors based on CsPbBr3/MoSe2 heterostructure.This work not only offers insights into the improved performance of photodetectors based on LHPs/TMDs heterostructures but it also provides guidelines for designing high-efficiency optoelectronic devices based on LHPs/TMDs heterostructures.
基金Project supported by the National Natural Science Foundation of China(Grant No.11804057)the National Key R&D Program of China(Grant No.2017YFB0701500)the Natural Science Foundation of Guangdong,China(Grant Nos.2017B030306003 and 2020A1515010862)。
文摘With the formation of structural vacancies,zirconium nitrides(key materials for cutting coatings,super wearresistance,and thermal barrier coatings) display a variety of compositions and phases featuring both cation and nitrogen enrichment.This study presents a systematic exploration of the stable crystal structures of zirconium heminitride combining the evolutionary algorithm method and ab initio density functional theory calculations at pressures of 0 GPa,30 GPa,60 GPa,90 GPa,120 GPa,150 GPa,and 200 GPa.In addition to the previously proposed phases P42/mnm-,Pnnn-,and Cmcm-Zr2 N,five new high-pressure Zr_(2)N phases of PA/nmm,IA/mcm,P2_(1)/m,P3 m1,and C2/m are discovered.An enthalpy study of these candidate configurations reveals various structural phase transformations of Zr2 N under pressure.By calculating the elastic constants and phonon dispersion,the mechanical and dynamical stabilities of all predicted structures are examined at ambient and high pressures.To understand the structure-property relationships,the mechanical properties of all Zr_(2)N compounds are investigated,including the elastic moduli,Vickers hardness,and directional dependence of Young’s modulus.The Cmncm-Zr2 N phase is found to belong to the brittle materials and has the highest Vickers hardness(12.9 GPa) among all candidate phases,while the I4/mcm-Zr2 N phase is the most ductile and has the lowest Vickers hardness(2.1 GPa).Furthermore,the electronic mechanism underlying the diverse mechanical behaviors of Zr2 N structures is discussed by analyzing the partial density of states.
基金Project supported by the Science and Technology Program of Guangzhou City(Grant Nos.202102020389 and 202103030001)the Fund of Guangdong Provincial Key Laboratory of Information Photonics Technology(Grant No.2020B121201011)the National Natural Science Foundation of China(Grant Nos.11804058 and 12064027)。
文摘The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise to strong anharmonicities and low lattice thermal conductivities.The double anions with distinctly different electronegativities of Mo_(2)AB_(2)monolayers can reduce the correlation between electron transport and phonon scattering,and further benefit much to their good thermoelectric properties.Thermoelectric properties of these Mo_(2)AB_(2)monolayers exhibit obvious anisotropies due to the direction-dependent chemical bondings and transport properties.Furthermore,their thermoelectric properties strongly depend on carrier type(n-type or p-type),carrier concentration and temperature.It is found that n-type Mo_(2)AB_(2)monolayers can be excellent thermoelectric materials with high electric conductivity,σ,and figures of merit,ZT.Choosing the types of A and B anions of Mo_(2)AB_(2)is an effective strategy to optimize their thermoelectric performance.These results provide rigorous understanding on thermoelectric properties of double-anions compounds and important guidance for achieving high thermoelectric performance in multi-anion compounds.
基金Project supported by the Guangdong Natural Science Foundation of China (Grant Nos. 2017B030306003 and 2019B1515120078)the National Natural Science Foundation of China (Grant No. 11804057)。
文摘The study of boron structure is fascinating because boron has various allotropes containing boron icosahedrons under pressure. Here, we propose a new boron structure(space group Fm3m) that is dynamically stable at 1.4 tera-Pascal(TPa)using density functional theory and an evolutionary algorithm. The unit cell of this structure can be viewed as a structure with a boron atom embedded in the icosahedron. This structure behaves as a metal, and cannot be stable under ambient pressure. Furthermore, we found electrons gather in lattice interstices, which is similar to that of the semiconductor Na or Ca_(2)N-Ⅱ under high pressure. The discovery of this new structure expands our comprehension of high-pressure condensed matter and contributes to the further development of high-pressure science.
基金Project supported by the National Natural Science Foundation of China(Grant No.11804057)the Natural Science Foundation of Guangdong Province,China(Grant No.2017B030306003)the National Key Research and Development Program of China(Grant No.2017YFB0701500).
文摘The site occupancy behavior of ternary alloying elements inγ'-Ni3Al(a key strengthening phase of commercial Ni-based single-crystal superalloys)can change with temperature and alloy composition owing to the effect of entropy.Using a total-energy method based on density functional theory,the dependence of tensile and shear behaviors on the site preference of alloying elements inγ'-Ni3Al were investigated in detail.Our results demonstrate that Fe,Ru,and Ir can significantly improve the ideal tensile and shear strength of theγ'phase when occupying the Al site,with Ru resulting in the strongest enhancement.In contrast,elements with fully filled d orbitals(i.e.,Cu,Zn,Ag,and Cd)are expected to reduce the ideal tensile and shear strength.The calculated stress-strain relationships of Ni3Al alloys indicate that none of the alloying elements can simultaneously increase the ideal strength of theγ'phase for both Ni1-site and Ni2-site substitutions.In addition,the charge redistribution and the bond length of the alloying elements and host atoms during the tensile and shear processes are analyzed to unveil the underlying electronic mechanisms.
基金National Natural Science Foundation of China(62131018,12104100)Natural Science Foundation of Guangdong Province(2022A1515010027)+1 种基金Guangzhou Municipal Science and Technology Project(SL2022A04J01205)Nanovision Technology(Beijing)Co.,Ltd.(607230264)。
文摘2D-material-based photodetectors enhanced by plasmonic nanostructures can support responsivity/detectivity several orders higher than commercial photodetectors,drawing extensive attention as promising candidates for the next-generation photodetectors.However,to boost the nanostructure-enhanced 2D photodetectors into real-world applications,crucial challenges lie in the design of broadband enhancing nanostructures and their scalable and position-controllable fabrication.Here,based on a broadband resonant plasmonic disk array fabricated by a scalable and position-controllable technique(direct writing photolithography),we present a visible-near infrared(405-1310 nm)2D WS_(2) photodetector,whose detectivity is up to 3.9×10^(14)Jones,a value exceeding that of the previous plasmon-enhanced 2D photodetectors.The broadened spectral response range and the high detectivity originate from the hot electron injection,optical absorption enhancement,and strain effect supported by the plasmonic array.Furthermore,the designed plasmonic 2D photodetector supports self-powered photodetection,indicating promising potential in energy-free and portable optoelectronic systems.Our results demonstrate an effective method to construct high-performance broadband photodetectors,which can facilitate the development of 2D photodetectors in commercial applications.
基金supported by the National Natural Science Foundation of China(62175040 and 61805044)the Science and Technology Program of Guangzhou(202201010242)+1 种基金Guangdong Provincial Key Laboratory of Information Photonics Technology(2020B121201011)the Pearl River Talent Recruitment Program(2019ZT08X639)。
基金supported by the Key-Area Research and Development Program of Guangdong Province(grant no.2020B0909-19005)the National Natural Science Foundation of China(grant nos.21975056 and 22179025)+1 种基金The Major and Special Project in the Field of Intelligent Manufacturing of the Universities in Guangdong Province(grant no.2020ZDZX2067)the Natural Science Foundation of Huizhou University(grant no.HZU202004).
文摘With advantages of low costs and high energy density,Li–S batteries are considered as one of the most promising energy storage devices.However,Li_(2)S_(2) with a high dissociation energy and insulative properties is hard to convert into Li_(2)S,resulting in underutilization of sulfur capacity.Herein,Co-Mo_(2)C@C yolk–shell spheres as nanoreactors were designed to confront this challenge rationally.The Co-Mo_(2)C@C-induced Li_(2)S_(1/2) nucleation and growth in the three-dimensional process and the cathode produced more Li_(2)S after full discharge.Experimental studies and theoretical calculations reveal that the conversion barrier from Li_(2)S_(2) into Li_(2)S was lowered while the diffusion of lithium ions and electron transfer accelerated when using the Co-Mo_(2)C@C catalyst.Based on the above advantages,the Co-Mo_(2)C@C/S cathode exhibits a high reversible capacity and excellent cyclic stability,such as an initial specific capacity of 1200 mAh g^(−1) at 0.1 C with 709 mAh g^(−1) at 1.0 C after 1000 cycles with a low capacity fading rate of 0.04%per cycle.Even at high densities of 3.0 C and 5.0 C,the specific capacities are 647.6 and 557.7 mAh g^(−1) after 400 cycles,respectively.Impressively,it also shows ca.770 and 900 mAh g^(−1) at 0.2 C after 50 cycles with high sulfur loadings of 4.2 and 5.1 mg cm−2,respectively.The present work may provide new insights into the design of nanoreactors to promote Li_(2)S_(1/2) growth in a three-dimensional process and accelerate conversion from solid Li_(2)S_(2) to solid Li_(2)S in high performance Li–S batteries.
基金financially supported by the National Natural Science Foundation of China(11804058,61571415,11674310 and 61622406)the financial support from RIE2020 AME Programmatic Grant A18A1b0045 funded by A*STARSERC,Singaporethe supports from the Agency for Science,Technology and Research(A*STAR)。
文摘Recent years have seen swift increase in the power conversion efficiency of perovskite solar cells(PSCs)Interface engineering is a promising route for further improving the performance of PSCs.Here we perform firstprinciples calculations to explore the effect of four candidate buffer materials(MACl,MAI,PbCl2and PbI2)on the electronic structures of the interface between MAPbI3absorber and TiO2.We find that MAX(X=Cl,I)as buffer layers will introduce a high electron barrier and enhance the electronhole recombination.Additionally,MAX does not passivate the surface states well.The conduction band minimum of PbI2is much lower than that of MAPbI3absorber,which significantly limits the band bending of the absorber and open-circuit voltage of solar cells.On the other side,suitable bandedge energy level positions,small lattice mismatch with TiO2surfaces,and excellent surface passivation make PbCl2a promising buffer material for absorber/electron-transport-layer interface engineering in PSCs.Our results in this work thus provide deep understanding on the effects of interface engineering with a buffer layer,which shall be useful for improving the performance of PSCs and related optoelectronics.
基金Work at Ames Laboratory was supported by the U.S.Department of Energy(DOE),Office of Science,Basic Energy Sciences,Materials Science and Engineering Division including a grant of computer time at the National Energy Research Scientific Computing Centre(NERSC)in Berkeley,CA.Ames Laboratory is operated for the U.S.DOE by Iowa State University under Contract No.DE-AC02-07CH11358Work at Guangdong University of Technology was supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515110328&2022A1515012174)+2 种基金the Guangdong Natural Science Foundation of China(Grant No.2019B1515120078)R.H.Wang and H.F.Dong also thank Center of Campus Network&Modern Educational Technology,Guangdong University of Technology,Guangdong,China for providing computational resources and technical support for this work.T.J.S was supported by the U.S.Department of Energy,Office of Basic Energy Sciences,through Ames Laboratory under its Contract with Iowa State University(No.DE-AC02-07CH11358)and through the Center for Advancement of Topological Semimetals(CATS)T.J.S.was also supported by the Gordon and Betty Moore Foundation(Grant No.GBMF4411).
文摘Ternary compounds with an immiscible pair of elements are relatively unexplored but promising for novel quantum materials discovery.Exploring what third element and its ratio that can be added to make stable ternary compounds out of an immiscible pair of elements remains a great challenge.In this work,we combine a machine learning(ML)method with ab initio calculations to efficiently search for the energetically favorable ternary La-Co-Pb compounds containing immiscible elements Co and Pb.Three previously reported structures are correctly captured by our approach.Moreover,we predict a ground state La_(3)CoPb compound and 57 low-energy La-Co-Pb ternary compounds.Attempts to synthesize La_(3)CoPb via multiple techniques produce mixed or multi-phases samples with,at best,ambiguous signals of the predicted lowest-energy La_(3)CoPb and the second lowest-energy La_(18)Co_(28)Pb_(3)phases.The calculated results of Gibbs free energy are consistent with experiments,and will provide very useful guidance for further experimental synthesis.
