Two-dimensional(2D)ferroelectric compounds are a special class of materials that meet the need for devices miniaturization,which can lead to a wide range of applications.Here,we investigate ferroelectric properties of...Two-dimensional(2D)ferroelectric compounds are a special class of materials that meet the need for devices miniaturization,which can lead to a wide range of applications.Here,we investigate ferroelectric properties of monolayer group-IV monochalcogenides MX(M=Sn,Ge;X=Se,Te,S)via strain engineering,and their effects with contaminated hydrogen are also discussed.GeSe,GeTe,and GeS do not go through transition up to the compressive strain of-5%,and consequently have good ferroelectric parameters for device applications that can be further improved by applying strain.According to the calculated ferroelectric properties and the band gaps of these materials,we find that their band gap can be adjusted by strain for excellent photovoltaic applications.In addition,we have determined the most stable hydrogen occupancy location in the monolayer SnS and SnTe.It reveals that H prefers to absorb on SnS and SnTe monolayers as molecules rather than atomic H.As a result,hydrogen molecules have little effect on the polarization and electronic structure of monolayer SnTe and SnS.展开更多
Diamond,as an ultra-wide bandgap semiconductor,has become a promising candidate for next-generation microelec-tronics and optoelectronics due to its numerous advantages over conventional semiconductors,including ultra...Diamond,as an ultra-wide bandgap semiconductor,has become a promising candidate for next-generation microelec-tronics and optoelectronics due to its numerous advantages over conventional semiconductors,including ultrahigh carrier mo-bility and thermal conductivity,low thermal expansion coefficient,and ultra-high breakdown voltage,etc.Despite these ex-traordinary properties,diamond also faces various challenges before being practically used in the semiconductor industry.This review begins with a brief summary of previous efforts to model and construct diamond-based high-voltage switching diodes,high-power/high-frequency field-effect transistors,MEMS/NEMS,and devices operating at high temperatures.Following that,we will discuss recent developments to address scalable diamond device applications,emphasizing the synthesis of large-area,high-quality CVD diamond films and difficulties in diamond doping.Lastly,we show potential solutions to modulate diamond’s electronic properties by the“elastic strain engineering”strategy,which sheds light on the future development of diamond-based electronics,photonics and quantum systems.展开更多
We study the effect of strain on band structure and valley-dependent transport properties of graphene heterojunctions.It is found that valley-dependent separation of electrons can be achieved by utilizing strain and o...We study the effect of strain on band structure and valley-dependent transport properties of graphene heterojunctions.It is found that valley-dependent separation of electrons can be achieved by utilizing strain and on-site energies.In the presence of strain,the values of transmission can be effectively adjusted by changing the strengths of the strain,while the transport angle basically keeps unchanged.When an extra on-site energy is simultaneously applied to the central scattering region,not only are the electrons of valleys K and K'separated into two distinct transmission lobes in opposite transverse directions,but the transport angles of two valleys can be significantly changed.Therefore,one can realize an effective modulation of valley-dependent transport by changing the strength and stretch angle of the strain and on-site energies,which can be exploited for graphene-based valleytronics devices.展开更多
Proton exchange membrane fuel cells(PEMFCs)are playing irreplaceable roles in the construction of the future sustainable energy system.However,the insufficient performance of platinum(Pt)-based electrocatalysts for ox...Proton exchange membrane fuel cells(PEMFCs)are playing irreplaceable roles in the construction of the future sustainable energy system.However,the insufficient performance of platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)hinders the overall efficiency of PEMFCs.Engineering the surface strain of catalysts is considered an effective way to tune their electronic structures and therefore optimize catalytic behavior.In this paper,insights into strain engineering for improving Pt-based catalysts toward ORR are elaborated in detail.First,recent advances in understanding the strain effects on ORR catalysts are comprehensively discussed.Then,strain engineering methodologies for adjusting Ptbased catalysts are comprehensively discussed.Finally,further information on the various challenges and potential prospects for strain modulation of Pt-based catalysts is provided.展开更多
Electrocatalysis is becoming more and more important in energy conversion and storage due to rising energy demands,increasing carbon dioxide emissions,and impending climate change.The design and synthesis of high-perf...Electrocatalysis is becoming more and more important in energy conversion and storage due to rising energy demands,increasing carbon dioxide emissions,and impending climate change.The design and synthesis of high-performance electrocatalysts are the spotlights of electrocatalysis.Among many design methodologies reported,strain engineering has gained growing attention because it can change the atomic arrangement and lattice structure of electrocatalysts.However,strain engineering remains to be problematic in regulating the properties of electrocatalysts.This review discusses the strain effect tactics to regulate metal and non-metal electrocatalysts,including three sections focusing on strain categorization,strain regulation mechanism,and applications in electrocatalysis,respectively.Finally,the current challenges and an outlook of strain engineering are discussed.展开更多
Photoelectrochemical water splitting using solar energy,generating oxygen and hydrogen is one of the clean fuel production processes.Inspired by surface-dependent characteristics of Janus structures,a newly designed J...Photoelectrochemical water splitting using solar energy,generating oxygen and hydrogen is one of the clean fuel production processes.Inspired by surface-dependent characteristics of Janus structures,a newly designed Janus monolayer Silicon Phosphorous Arsenide(SiPAs)was analyzed with Density Functional Theory(DFT)methods.Hybrid exchange-correlation functional(HSE06)combined with Wannier90-based analysis for electronic and optical properties of SiPAs reveals that it can act as a photocatalyst.SiPAs show an indirect bandgap of 1.88 eV,absorbing visible light range is 350 to 500 nm.The phonon spectrum confirms dynamic stability.The exciton binding energy is computed with GW/BSE methods.The electronic band edge positions are at-5.75 and-4.43 eV,perfectly straddling the water redox potentials.Interestingly the strain application modifies the bandgap and also non-homogenously widens the absorption band.A novel range of photocatalyst designs with Group IV-V elements with great promise for water-splitting,photovoltaic,and narrow bandgap semiconductor(optoelectronics)applications may be feasible.展开更多
Interphase strain engineering provides a unique methodology to significantly modify the lattice structure across a single film,enabling the emergence and manipulation of novel functionalities that are inaccessible in ...Interphase strain engineering provides a unique methodology to significantly modify the lattice structure across a single film,enabling the emergence and manipulation of novel functionalities that are inaccessible in the context of traditional strain engineering methods.In this work,by using the interphase strain,we achieve a ferromagnetic state with enhanced Curie temperature and a room-temperature polar state in EuO secondary phase-tunned EuTiO_(3) thin films.A combination of atomic-scale electron microscopy and synchrotron X-ray spectroscopy unravels the underlying mechanisms of the ferroelectric and ferromagnetic properties enhancement.Wherein,the EuO secondary phase is found to be able to dramatically distort the TiO_6 octahedra,which favors the non-centrosymmetric polar state,weakens antiferromagnetic Eu-Ti-Eu interactions,and enhances ferromagnetic Eu-O-Eu interactions.Our work demonstrates the feasibility and effectiveness of interphase strain engineering in simultaneously promoting ferroelectric and ferromagnetic performance,which would provide new thinking on the property regulation of numerous strongly correlated functional materials.展开更多
Two dimensional(2D)materials have attracted extensive research interests due to their excellent properties related to unique structure.Strain engineering,as an important strategy for tuning the lattice and electronic ...Two dimensional(2D)materials have attracted extensive research interests due to their excellent properties related to unique structure.Strain engineering,as an important strategy for tuning the lattice and electronic structure of 2D mate-rials,has been widely used in the modulation of physical properties,which broadens their applications in flexible nanoelectronic and optoelectronic devices.In this review,we fist summari ze the methods of inducing strain to 2D materials and discuss the advantages and problems of various methods.We then introduce the strain induced effects on optical,electrical,and magnetic proper-ties,together with the phase transition of 2D materials.Finally,we ilustrate the potential applications of strained 2D materials and further look forward to their opportunities and challenges in practical applications in the future.展开更多
Strain is a powerful tool to modify the optical properties of semiconducting transition metal dichalcogenides like MoS_(2),MoSe_(2),WS_(2) and WSe_(2).In this work we provide a thorough description of the technical de...Strain is a powerful tool to modify the optical properties of semiconducting transition metal dichalcogenides like MoS_(2),MoSe_(2),WS_(2) and WSe_(2).In this work we provide a thorough description of the technical details to perform uniaxial strain measurements on these two-dimensional semiconductors and we provide a straightforward calibration method to determine the amount of applied strain with high accuracy.We then employ reflectance spectroscopy to analyze the strain tunability of the electronic properties of single-,bi-and tri-layer MoS_(2),MoSe_(2),WS_(2) and WSe_(2).Finally,we quantify the flake-to-flake variability by analyzing 15 different single-layer MoS_(2) flakes.展开更多
Strain engineering is a powerful approach for tuning various properties of functional materials. The influences of lattice strain on the Li-ion migration energy barrier of lithium-ions in layered LiCoO_(2) have been s...Strain engineering is a powerful approach for tuning various properties of functional materials. The influences of lattice strain on the Li-ion migration energy barrier of lithium-ions in layered LiCoO_(2) have been systemically studied using lattice dynamics simulations, analytical function and neural network method. We have identified two Li-ion migration paths, oxygen dumbbell hop (ODH), and tetrahedral site hop (TSH) with different concentrations of local defects. We found that Li-ion migration energy barriers increased with the increase of pressure for both ODH and TSH cases, while decreased significantly with applied tensile uniaxial c-axis strain for ODH and TSH cases or compressive in-plane strain for TSH case. Our work provides the complete strain-map for enhancing the diffusivity of Li-ion in LiCoO_(2), and therefore, indicates a new way to achieve better rate performance through strain engineering.展开更多
Strain engineering is proposed to be an effective technology to tune the properties of two-dimensional(2D)transition metal dichalcogenides(TMDCs).Conventional strain engineering techniques(e.g.,mechanical bending,heat...Strain engineering is proposed to be an effective technology to tune the properties of two-dimensional(2D)transition metal dichalcogenides(TMDCs).Conventional strain engineering techniques(e.g.,mechanical bending,heating)cannot conserve strain due to their dependence on external action,which thereby limits the application in electronics.In addition,the theoretically predicted strain-induced tuning of electrical performance of TMDCs has not been experimentally proved yet.Here,a facile but effective approach is proposed to retain and tune the biaxial tensile strain in monolayer MoS_(2) by adjusting the process of the chemical vapor deposition(CVD).To prove the feasibility of this method,the strain formation model of CVD grown MoS_(2) is proposed which is supported by the calculated strain dependence of band gap via the density functional theory(DFT).Next,the electrical properties tuning of strained monolayer MoS_(2) is demonstrated in experiment,where the carrier mobility of MoS_(2) was increased by two orders(~0.15 to~23 cm^(2)·V^(−1)·s^(−1)).The proposed pathway of strain preservation and regulation will open up the optics application of strain engineering and the fabrication of high performance electronic devices in 2D materials.展开更多
Strain engineering can serve as a powerful technique for modulating the exotic properties arising from the atomic structure of materials.Examples have been demonstrated that one-dimensional(1D)structure can serve as a...Strain engineering can serve as a powerful technique for modulating the exotic properties arising from the atomic structure of materials.Examples have been demonstrated that one-dimensional(1D)structure can serve as a great platform for modulating electronic band structure and phonon dispersion via strain control.Particularly,in a van der Waals material silicon diphosphide(SiP_(2)),quasi-1D zigzag phosphorus–phosphorus(P–P)chains are embedded inside the crystal structure,and can show unique phonon vibration modes and realize quasi-1D excitons.Manipulating those optical properties by the atom displacements via strain engineering is of great interest in understanding underlying mechanism of such P–P chains,however,which remains elusive.Herein,we demonstrate the strain engineering of Raman and photoluminescence(PL)spectra in quasi-1D P–P chains and resulting in anisotropic manipulation in SiP_(2).We find that the phonon frequencies of SiP_(2)in Raman spectra linearly evolve with a uniaxial strain along/perpendicular to the quasi-1D P–P chain directions.Interestingly,by applying tensile strain along the P–P chains,the band gap energy of strained SiP_(2)can significantly decrease with a tunable value of~55 meV.Based on arsenic(As)element doping into SiP_(2),the strain-induced redshifts of phonon frequencies decrease,indicating the stiffening of the phonon vibration with the increased arsenic doping level.Such results provide an opportunity for strain engineering of the light–matter interactions in the quasi-1D P–P chains of SiP_(2)crystal for potential optical applications.展开更多
Two-dimensional(2D)semiconductors exhibit great potential to minimize the size and drastically reduce the energy consumption of optoelectronic devices due to promising features induced by quantum confinement.It has ac...Two-dimensional(2D)semiconductors exhibit great potential to minimize the size and drastically reduce the energy consumption of optoelectronic devices due to promising features induced by quantum confinement.It has achieved many successes in infra-red and visible light optoelectronic devices.The study on ultra-wide band gap 2D semiconductors except h-BN are still limited,however,the requirement is more and more urgent.Inspired by the progresses of III-nitride semiconductors in recent several decades,2D AlN is highly expected to be a new member of ultra-wide band gap 2D semiconductors.In this work,we employed the first-principles calculations to investigate the structural and electronic properties of 2D AlN.We revealed that few-layer AlN acquires a square-octagon(so-AlN)configuration in the vertical direction when the number of atomic layers n is smaller than 16.With increasing the thickness from 2 ML to 8 ML,the band gap decreased due to the weakening of quantum confinement effect.We demonstrated the intrinsic indirect band gap can be tuned to be direct by applying different direction strains for so-AlN.Our results open new avenues for their application in nano-optoelectronics.展开更多
Direct alcohol fuel cells(DAFCs)are powered by the alcohol electro-oxidation reaction(AOR),where an electrocatalyst with an optimal electronic structure can accelerate the sluggish AOR.Interestingly,strain engineering...Direct alcohol fuel cells(DAFCs)are powered by the alcohol electro-oxidation reaction(AOR),where an electrocatalyst with an optimal electronic structure can accelerate the sluggish AOR.Interestingly,strain engineering in hetero-catalysis offers a promising route to boost their catalytic activity.Herein,we report on a class of monodispersed ultrathin twisty PdBi alloy nanowires(TNWs)assemblies with face-centered structures that drive AORs.These thin nanowire structures expose a large number of reactive sites.Strikingly,Pd_(6)Bi_(1)TNWs show an excellent current density of 2066,3047,and 1231 mA mg_(Pd)^(-1)for oxidation of ethanol,ethylene glycol,and glycerol,respectively.The“volcano-like”behaviors observed on PdBi TNWs for AORs indicate that the maximum catalytic mass activity is a well balance between active intermediates and blocking species at the interface.This study offers an effective and universal method to build novel nanocatalysts in various applications by rationally designing highly efficient catalysts with specific strain.展开更多
Y_(3)Fe_(5)O_(12)(YIG) and Bi Y_(3)Fe_(5)O_(12)(Bi:YIG) films were epitaxially grown on a series of(111)-oriented garnet substrates using pulsed laser deposition. Structural and ferromagnetic resonance characterizatio...Y_(3)Fe_(5)O_(12)(YIG) and Bi Y_(3)Fe_(5)O_(12)(Bi:YIG) films were epitaxially grown on a series of(111)-oriented garnet substrates using pulsed laser deposition. Structural and ferromagnetic resonance characterizations demonstrated the high epitaxial quality, extremely low magnetic loss and coherent strain state in these films. Using these epitaxial films as model systems, we systematically investigated the evolution of magnetic anisotropy(MA) with epitaxial strain and chemical doping. For both the YIG and Bi:YIG films, the compressive strain tends to align the magnetic moment in the film plane while the tensile strain can compete with the demagnetization effect and stabilize perpendicular MA. We found that the strain-induced lattice elongation/compression along the out-of-plane [111] axis is the key parameter that determines the MA. More importantly, the strain-induced tunability of MA can be enhanced significantly by Bi doping;meanwhile, the ultralow damping feature persists. We clarified that the cooperation between strain and chemical doping could realize an effective control of MA in garnet-type ferrites, which is essential for spintronic applications.展开更多
We report the strong dependence of resistance on uniaxial strain in monolayer WSe_(2)at various temperatures,where the gauge factor can reach as large as 2400.The observation of strain-dependent resistance and giant g...We report the strong dependence of resistance on uniaxial strain in monolayer WSe_(2)at various temperatures,where the gauge factor can reach as large as 2400.The observation of strain-dependent resistance and giant gauge factor is attributed to the emergence of nonzero Berry curvature dipole.Upon increasing strain,Berry curvature dipole can generate net orbital magnetization,which would introduce additional magnetic scattering,decreasing the mobility and thus conductivity.Our work demonstrates the strain engineering of Berry curvature and thus the transport properties,making monolayer WSe_(2)potential for application in the highly sensitive strain sensors and high-performance flexible electronics.展开更多
The low-dimensional,highly anisotropic geometries,and superior mechanical properties of one-dimensional(1D) nanomaterials allow the exquisite strain engineering with a broad tunability inaccessible to bulk or thin-fil...The low-dimensional,highly anisotropic geometries,and superior mechanical properties of one-dimensional(1D) nanomaterials allow the exquisite strain engineering with a broad tunability inaccessible to bulk or thin-film materials.Such capability enables unprecedented possibilities for probing intriguing physics and materials science in the 1-D limit.Among the techniques for introducing controlled strains in 1D materials,nanoimprinting with embossed substrates attracts increased attention due to its capability to parallelly form nanomaterials into wrinkled structures with controlled periodicities,amplitudes,orientations at large scale with nanoscale resolutions.Here,we systematically investigated the strain-engineered anisotropic optical properties in Te nanowires through introducing a controlled strain field using a resist-free thermally assisted nanoimprinting process.The magnitude of induced strains can be tuned by adjusting the imprinting pressure,the nanowire diameter,and the patterns on the substrates.The observed Raman spectra from the chiral-chain lattice of 1D Te reveal the strong lattice vibration response under the strain.Our results suggest the potential of 1D Te as a promising candidate for flexible electronics,deformable optoelectronics,and wearable sensors.The experimental platform can also enable the exquisite mechanical control in other nanomaterials using substrate-induced,on-demand,and controlled strains.展开更多
Previous experimental and computational results have confirmed that the thermal conductivity of a twodimensional(2D) material can be considerably affected by strain. Numerous attention has been paid to explore the rel...Previous experimental and computational results have confirmed that the thermal conductivity of a twodimensional(2D) material can be considerably affected by strain. Numerous attention has been paid to explore the relevant mechanisms. However, the strain effects on the interfacial thermal conductance(ITC) of 2D heterostructure have attracted little attention. Herein, the non-equilibrium molecular dynamics(NEMD) simulations were conducted to the graphene/hexagonal boron nitride(GR/h-BN) heterostructure to investigate the strain effects on the ITC. Three types of strains were considered, i.e., tensile strain, compressive strain, and shear strain.The results indicate that the strain can adjust the ITC for the GR/h-BN heterostructure effectively, and the strain loading direction also influences the ITC. Generally, the tensile strain reduces the ITC of the heterostructure, in addition to the BN-C system at small tensile strain;both the compressive strain and shear strain increase the ITC,especially at a small strain. For the NB-C system, it is more sensitive to the strain loading direction and the yx shear strain of 0.06 is the most effective way to strengthen the ITC. Our results also show that the out-of-plane deformation weakens the in-plane vibration of atoms, leading to a reduction of the interfacial thermal energy transport.展开更多
Layered trihalides exhibit distinctive band structures and physical properties due to the sixfold coordinated 3d or 4d transition metal site and partially occupied d orbitals,holding great potential in condensed matte...Layered trihalides exhibit distinctive band structures and physical properties due to the sixfold coordinated 3d or 4d transition metal site and partially occupied d orbitals,holding great potential in condensed matter physics and advanced electronic applications.Prior research focused on trihalides with highly symmetric honeycomb-like structures,such as CrI3 andα-RuCl_(3),while the role of crystal anisotropy in trihalides remains elusive.In particular,the trihalide MoCl_(3) manifests strong in-plane crystal anisotropy with the largest difference in Mo–Mo interatomic distances.Research on such material is imperative to address the lack of investigations on the effect of anisotropy on the properties of trihalides.Herein,we demonstrated the anisotropy of MoCl_(3) through polarized Raman spectroscopy and further tuned the phonon frequency via strain engineering.We showed the Raman intensity exhibits twofold symmetry under parallel configuration and fourfold symmetry under perpendicular configuration with changing the polarization angle of incident light.Furthermore,we found that the phonon frequencies of MoCl_(3) decrease gradually and linearly with applying uniaxial tensile strain along the axis of symmetry in the MoCl_(3) crystal,while those frequencies increase with uniaxial tensile strain applied perpendicularly.Our results shed light on the manipulation of anisotropic light-matter interactions via strain engineering,and lay a foundation for further exploration of the anisotropy of trihalides and the modulation of their electronic,optical,and magnetic properties.展开更多
Two-dimensional(2D)materials have received extensive attention in the fields of electronics,optoelectronics,and magnetic devices attributed to their unique electronic structures and physical properties.The application...Two-dimensional(2D)materials have received extensive attention in the fields of electronics,optoelectronics,and magnetic devices attributed to their unique electronic structures and physical properties.The application of strain is a simple and effective strategy to change the lattice structure of 2D materials thus modulating their physical properties,which further facilitate their applications in carrier mobility transistor,magnetic sensor,single-photon emitter etc.In this short review,we focus on the strain applied via substrate engineering.Firstly,the relationship between the strain and physical properties has been summarized.Secondly,the methods for achieving substrate engineering-induced strain have been demonstrated.Finally,the latest applications of strained 2D materials have been introduced.In addition,the future challenges and development prospects of strain-modulated 2D materials have also been proposed.展开更多
基金the National Natural Science Foundation of China(NSFC)(Grant No.12074126)the Foundation for Innovative Research Groups of NSFC(Grant No.51621001)the Fundamental Research Funds for the Central Universities(Grant No.2020ZYGXZR076).
文摘Two-dimensional(2D)ferroelectric compounds are a special class of materials that meet the need for devices miniaturization,which can lead to a wide range of applications.Here,we investigate ferroelectric properties of monolayer group-IV monochalcogenides MX(M=Sn,Ge;X=Se,Te,S)via strain engineering,and their effects with contaminated hydrogen are also discussed.GeSe,GeTe,and GeS do not go through transition up to the compressive strain of-5%,and consequently have good ferroelectric parameters for device applications that can be further improved by applying strain.According to the calculated ferroelectric properties and the band gaps of these materials,we find that their band gap can be adjusted by strain for excellent photovoltaic applications.In addition,we have determined the most stable hydrogen occupancy location in the monolayer SnS and SnTe.It reveals that H prefers to absorb on SnS and SnTe monolayers as molecules rather than atomic H.As a result,hydrogen molecules have little effect on the polarization and electronic structure of monolayer SnTe and SnS.
基金the support from the Research Grants Council of the Hong Kong Special Administrative Region,China(Grant RFS2021-1S05)the National Natural Science Foundation of China(Grant 11922215)+1 种基金the funding from the National Natural Science Foundation of China(Grant 11902200)the Science and Technology Commission of Shanghai Municipality(Grant19YF1433600)。
文摘Diamond,as an ultra-wide bandgap semiconductor,has become a promising candidate for next-generation microelec-tronics and optoelectronics due to its numerous advantages over conventional semiconductors,including ultrahigh carrier mo-bility and thermal conductivity,low thermal expansion coefficient,and ultra-high breakdown voltage,etc.Despite these ex-traordinary properties,diamond also faces various challenges before being practically used in the semiconductor industry.This review begins with a brief summary of previous efforts to model and construct diamond-based high-voltage switching diodes,high-power/high-frequency field-effect transistors,MEMS/NEMS,and devices operating at high temperatures.Following that,we will discuss recent developments to address scalable diamond device applications,emphasizing the synthesis of large-area,high-quality CVD diamond films and difficulties in diamond doping.Lastly,we show potential solutions to modulate diamond’s electronic properties by the“elastic strain engineering”strategy,which sheds light on the future development of diamond-based electronics,photonics and quantum systems.
基金National Natural Science Foundation of China(Grant No.11574067)。
文摘We study the effect of strain on band structure and valley-dependent transport properties of graphene heterojunctions.It is found that valley-dependent separation of electrons can be achieved by utilizing strain and on-site energies.In the presence of strain,the values of transmission can be effectively adjusted by changing the strengths of the strain,while the transport angle basically keeps unchanged.When an extra on-site energy is simultaneously applied to the central scattering region,not only are the electrons of valleys K and K'separated into two distinct transmission lobes in opposite transverse directions,but the transport angles of two valleys can be significantly changed.Therefore,one can realize an effective modulation of valley-dependent transport by changing the strength and stretch angle of the strain and on-site energies,which can be exploited for graphene-based valleytronics devices.
基金supported by the Natural Science Foundation of Shaanxi Province,China(Nos.2023-JC-YB-122,2024JCYBQN-0072)the High-level Innovation and Entrepreneurship Talent Project from Qinchuangyuan of Shaanxi Province,China(No.QCYRCXM-2022-226)+3 种基金the Fundamental Research Funds for the Central Universities,China(No.D5000210987)the Joint Fund Project-Enterprise-Shaanxi Coal Joint Fund Project,China(No.2021JLM-38)the National Natural Science Foundation of China(Grant No.22379123,No.22250710676)the Fujian Province Minjiang Scholar Program,China.
文摘Proton exchange membrane fuel cells(PEMFCs)are playing irreplaceable roles in the construction of the future sustainable energy system.However,the insufficient performance of platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)hinders the overall efficiency of PEMFCs.Engineering the surface strain of catalysts is considered an effective way to tune their electronic structures and therefore optimize catalytic behavior.In this paper,insights into strain engineering for improving Pt-based catalysts toward ORR are elaborated in detail.First,recent advances in understanding the strain effects on ORR catalysts are comprehensively discussed.Then,strain engineering methodologies for adjusting Ptbased catalysts are comprehensively discussed.Finally,further information on the various challenges and potential prospects for strain modulation of Pt-based catalysts is provided.
基金This research was supported by the National Natural Science Foundation of China(Nos.T2222002,21973079,22032004,and 21991130)the Natural Science Foundation of Fujian Province(No.2021J06008).
文摘Electrocatalysis is becoming more and more important in energy conversion and storage due to rising energy demands,increasing carbon dioxide emissions,and impending climate change.The design and synthesis of high-performance electrocatalysts are the spotlights of electrocatalysis.Among many design methodologies reported,strain engineering has gained growing attention because it can change the atomic arrangement and lattice structure of electrocatalysts.However,strain engineering remains to be problematic in regulating the properties of electrocatalysts.This review discusses the strain effect tactics to regulate metal and non-metal electrocatalysts,including three sections focusing on strain categorization,strain regulation mechanism,and applications in electrocatalysis,respectively.Finally,the current challenges and an outlook of strain engineering are discussed.
基金the financial support for conducting part of the computational work,by the Australian Government through the Australian Research Council(ARC)under the centre of Excellence scheme(Project No.CE170100026)National Computational Infrastructure(NCI),a National Facility for computing resources.S K M also acknowledges the computing system resources’support from the University of Tsukuba,Japan through the International Postdoctoral Fellowship of Japan Society for the Promotion of Science(JSPS)’s KAKENHI(Grant No.JP22F32733)+1 种基金during the computational work and finalization of this studyS K M also acknowledges the support of Mr Matta Sai Aneesh,University of Queensland,Australia while preparing the graphical abstract.
文摘Photoelectrochemical water splitting using solar energy,generating oxygen and hydrogen is one of the clean fuel production processes.Inspired by surface-dependent characteristics of Janus structures,a newly designed Janus monolayer Silicon Phosphorous Arsenide(SiPAs)was analyzed with Density Functional Theory(DFT)methods.Hybrid exchange-correlation functional(HSE06)combined with Wannier90-based analysis for electronic and optical properties of SiPAs reveals that it can act as a photocatalyst.SiPAs show an indirect bandgap of 1.88 eV,absorbing visible light range is 350 to 500 nm.The phonon spectrum confirms dynamic stability.The exciton binding energy is computed with GW/BSE methods.The electronic band edge positions are at-5.75 and-4.43 eV,perfectly straddling the water redox potentials.Interestingly the strain application modifies the bandgap and also non-homogenously widens the absorption band.A novel range of photocatalyst designs with Group IV-V elements with great promise for water-splitting,photovoltaic,and narrow bandgap semiconductor(optoelectronics)applications may be feasible.
基金supported by the National Key Basic Research Program of China(Nos.2020YFA0309100 and 2019YFA0308500)the National Natural Science Foundation of China(Nos.21825102,22001014,11294029,11974390,11721404)+6 种基金the China National Postdoctoral Program for Innovative Talents(No.BX20200043)China Postdoctoral Science Foundation(No.2021M690366)the Beijing Nova Program of Science and Technology(No.Z191100001119112)the Beijing Natural Science Foundation(No.2202060)the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology,the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(No.XDB33030200)the Fundamental Research Funds for the Central Universities,China(Nos.06500145 and FRF-IDRY-20–039)State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF202110)。
文摘Interphase strain engineering provides a unique methodology to significantly modify the lattice structure across a single film,enabling the emergence and manipulation of novel functionalities that are inaccessible in the context of traditional strain engineering methods.In this work,by using the interphase strain,we achieve a ferromagnetic state with enhanced Curie temperature and a room-temperature polar state in EuO secondary phase-tunned EuTiO_(3) thin films.A combination of atomic-scale electron microscopy and synchrotron X-ray spectroscopy unravels the underlying mechanisms of the ferroelectric and ferromagnetic properties enhancement.Wherein,the EuO secondary phase is found to be able to dramatically distort the TiO_6 octahedra,which favors the non-centrosymmetric polar state,weakens antiferromagnetic Eu-Ti-Eu interactions,and enhances ferromagnetic Eu-O-Eu interactions.Our work demonstrates the feasibility and effectiveness of interphase strain engineering in simultaneously promoting ferroelectric and ferromagnetic performance,which would provide new thinking on the property regulation of numerous strongly correlated functional materials.
基金the National Natural Science Foundation of China,Grant/AwardNumbers:51520105002,51972007。
文摘Two dimensional(2D)materials have attracted extensive research interests due to their excellent properties related to unique structure.Strain engineering,as an important strategy for tuning the lattice and electronic structure of 2D mate-rials,has been widely used in the modulation of physical properties,which broadens their applications in flexible nanoelectronic and optoelectronic devices.In this review,we fist summari ze the methods of inducing strain to 2D materials and discuss the advantages and problems of various methods.We then introduce the strain induced effects on optical,electrical,and magnetic proper-ties,together with the phase transition of 2D materials.Finally,we ilustrate the potential applications of strained 2D materials and further look forward to their opportunities and challenges in practical applications in the future.
基金This project has received funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(grant agreement no 755655,ERC-StG 2017 project 2D-TOPSENSE)R.F.acknowledges the support from the Spanish Ministry of Economy,Industry and Competitiveness through a Juan de la Cierva-formación fellowship 2017 FJCI-2017-32919.H.L.acknowledges the grant from China Scholarship Council(CSC)under No.201907040070.
文摘Strain is a powerful tool to modify the optical properties of semiconducting transition metal dichalcogenides like MoS_(2),MoSe_(2),WS_(2) and WSe_(2).In this work we provide a thorough description of the technical details to perform uniaxial strain measurements on these two-dimensional semiconductors and we provide a straightforward calibration method to determine the amount of applied strain with high accuracy.We then employ reflectance spectroscopy to analyze the strain tunability of the electronic properties of single-,bi-and tri-layer MoS_(2),MoSe_(2),WS_(2) and WSe_(2).Finally,we quantify the flake-to-flake variability by analyzing 15 different single-layer MoS_(2) flakes.
基金This work was supported by XMUM Research Fund XMUMRF/2019-C3/IORI/0001.
文摘Strain engineering is a powerful approach for tuning various properties of functional materials. The influences of lattice strain on the Li-ion migration energy barrier of lithium-ions in layered LiCoO_(2) have been systemically studied using lattice dynamics simulations, analytical function and neural network method. We have identified two Li-ion migration paths, oxygen dumbbell hop (ODH), and tetrahedral site hop (TSH) with different concentrations of local defects. We found that Li-ion migration energy barriers increased with the increase of pressure for both ODH and TSH cases, while decreased significantly with applied tensile uniaxial c-axis strain for ODH and TSH cases or compressive in-plane strain for TSH case. Our work provides the complete strain-map for enhancing the diffusivity of Li-ion in LiCoO_(2), and therefore, indicates a new way to achieve better rate performance through strain engineering.
基金This work was financially supported by the National Science Foundation of China(Nos.61922005,U1930105,21673054 and 11874130)Beijing Natural Science Foundation(No.JQ20027)+1 种基金the Beijing Excellent Talent Program,the Equipment Preresearch Project of China Electronics Technology Group Corporation(CETC)(No.6141B08110104)the General Program of Science and Technology Development Project of Beijing Municipal Education Commission(No.KM202010005005).
文摘Strain engineering is proposed to be an effective technology to tune the properties of two-dimensional(2D)transition metal dichalcogenides(TMDCs).Conventional strain engineering techniques(e.g.,mechanical bending,heating)cannot conserve strain due to their dependence on external action,which thereby limits the application in electronics.In addition,the theoretically predicted strain-induced tuning of electrical performance of TMDCs has not been experimentally proved yet.Here,a facile but effective approach is proposed to retain and tune the biaxial tensile strain in monolayer MoS_(2) by adjusting the process of the chemical vapor deposition(CVD).To prove the feasibility of this method,the strain formation model of CVD grown MoS_(2) is proposed which is supported by the calculated strain dependence of band gap via the density functional theory(DFT).Next,the electrical properties tuning of strained monolayer MoS_(2) is demonstrated in experiment,where the carrier mobility of MoS_(2) was increased by two orders(~0.15 to~23 cm^(2)·V^(−1)·s^(−1)).The proposed pathway of strain preservation and regulation will open up the optics application of strain engineering and the fabrication of high performance electronic devices in 2D materials.
基金the National Natural Science Foundation of China(Nos.51861145201,52072168,21733001,and 91750101)the National Key Basic Research Program of the Ministry of Science and Technology of China(Nos.2018YFA0306200 and 2021YFA1202901)Jiangsu Key Laboratory of Artificial Functional Materials.L.Y.F.acknowledges financial support from the start-up fund of Chongqing University(No.02110011044171).
文摘Strain engineering can serve as a powerful technique for modulating the exotic properties arising from the atomic structure of materials.Examples have been demonstrated that one-dimensional(1D)structure can serve as a great platform for modulating electronic band structure and phonon dispersion via strain control.Particularly,in a van der Waals material silicon diphosphide(SiP_(2)),quasi-1D zigzag phosphorus–phosphorus(P–P)chains are embedded inside the crystal structure,and can show unique phonon vibration modes and realize quasi-1D excitons.Manipulating those optical properties by the atom displacements via strain engineering is of great interest in understanding underlying mechanism of such P–P chains,however,which remains elusive.Herein,we demonstrate the strain engineering of Raman and photoluminescence(PL)spectra in quasi-1D P–P chains and resulting in anisotropic manipulation in SiP_(2).We find that the phonon frequencies of SiP_(2)in Raman spectra linearly evolve with a uniaxial strain along/perpendicular to the quasi-1D P–P chain directions.Interestingly,by applying tensile strain along the P–P chains,the band gap energy of strained SiP_(2)can significantly decrease with a tunable value of~55 meV.Based on arsenic(As)element doping into SiP_(2),the strain-induced redshifts of phonon frequencies decrease,indicating the stiffening of the phonon vibration with the increased arsenic doping level.Such results provide an opportunity for strain engineering of the light–matter interactions in the quasi-1D P–P chains of SiP_(2)crystal for potential optical applications.
基金This work was supported by the National Natural Science Foundation of China[61804152,61834008].
文摘Two-dimensional(2D)semiconductors exhibit great potential to minimize the size and drastically reduce the energy consumption of optoelectronic devices due to promising features induced by quantum confinement.It has achieved many successes in infra-red and visible light optoelectronic devices.The study on ultra-wide band gap 2D semiconductors except h-BN are still limited,however,the requirement is more and more urgent.Inspired by the progresses of III-nitride semiconductors in recent several decades,2D AlN is highly expected to be a new member of ultra-wide band gap 2D semiconductors.In this work,we employed the first-principles calculations to investigate the structural and electronic properties of 2D AlN.We revealed that few-layer AlN acquires a square-octagon(so-AlN)configuration in the vertical direction when the number of atomic layers n is smaller than 16.With increasing the thickness from 2 ML to 8 ML,the band gap decreased due to the weakening of quantum confinement effect.We demonstrated the intrinsic indirect band gap can be tuned to be direct by applying different direction strains for so-AlN.Our results open new avenues for their application in nano-optoelectronics.
基金supported by the National Natural Science Foundation of China(22172084 and 21773133)the World-Class Discipline Program of Shandong Province,China。
文摘Direct alcohol fuel cells(DAFCs)are powered by the alcohol electro-oxidation reaction(AOR),where an electrocatalyst with an optimal electronic structure can accelerate the sluggish AOR.Interestingly,strain engineering in hetero-catalysis offers a promising route to boost their catalytic activity.Herein,we report on a class of monodispersed ultrathin twisty PdBi alloy nanowires(TNWs)assemblies with face-centered structures that drive AORs.These thin nanowire structures expose a large number of reactive sites.Strikingly,Pd_(6)Bi_(1)TNWs show an excellent current density of 2066,3047,and 1231 mA mg_(Pd)^(-1)for oxidation of ethanol,ethylene glycol,and glycerol,respectively.The“volcano-like”behaviors observed on PdBi TNWs for AORs indicate that the maximum catalytic mass activity is a well balance between active intermediates and blocking species at the interface.This study offers an effective and universal method to build novel nanocatalysts in various applications by rationally designing highly efficient catalysts with specific strain.
基金supported by the National Basic Research Program of China (Grant No. 2020YFA0309100)the National Natural Science Foundation of China (Grant Nos. 12074365 and U2032218)+3 种基金the Fundamental Research Funds for the Central Universities (Grant Nos. WK9990000108, WK9990000102, and WK2030000035)Hefei Science Center CAS Foundation (Grant No. 2021HSC-UE010)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabricationthe magnetic characterizations were carried out in the Instruments Center for Physical Science, USTC。
文摘Y_(3)Fe_(5)O_(12)(YIG) and Bi Y_(3)Fe_(5)O_(12)(Bi:YIG) films were epitaxially grown on a series of(111)-oriented garnet substrates using pulsed laser deposition. Structural and ferromagnetic resonance characterizations demonstrated the high epitaxial quality, extremely low magnetic loss and coherent strain state in these films. Using these epitaxial films as model systems, we systematically investigated the evolution of magnetic anisotropy(MA) with epitaxial strain and chemical doping. For both the YIG and Bi:YIG films, the compressive strain tends to align the magnetic moment in the film plane while the tensile strain can compete with the demagnetization effect and stabilize perpendicular MA. We found that the strain-induced lattice elongation/compression along the out-of-plane [111] axis is the key parameter that determines the MA. More importantly, the strain-induced tunability of MA can be enhanced significantly by Bi doping;meanwhile, the ultralow damping feature persists. We clarified that the cooperation between strain and chemical doping could realize an effective control of MA in garnet-type ferrites, which is essential for spintronic applications.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFA0703703)the National Natural Science Foundation of China(Grant Nos.91964201,61825401,and 11774004).
文摘We report the strong dependence of resistance on uniaxial strain in monolayer WSe_(2)at various temperatures,where the gauge factor can reach as large as 2400.The observation of strain-dependent resistance and giant gauge factor is attributed to the emergence of nonzero Berry curvature dipole.Upon increasing strain,Berry curvature dipole can generate net orbital magnetization,which would introduce additional magnetic scattering,decreasing the mobility and thus conductivity.Our work demonstrates the strain engineering of Berry curvature and thus the transport properties,making monolayer WSe_(2)potential for application in the highly sensitive strain sensors and high-performance flexible electronics.
基金the College of Engineering and School of Industrial Engineering at Purdue University for startup supportpartially supported by the National Science Foundation under Grant CMMI-1762698+3 种基金financial assistance from ONR NEPTUNE program National Science Foundation under Grant CMMI-1538360supported by the Louis Beecherl, Jr. Endowment Fundsthe College of Engineering and School of Materials Engineering at Purdue University for startup supportsupported through computational resources provided by the Information Technology department at Purdue University。
文摘The low-dimensional,highly anisotropic geometries,and superior mechanical properties of one-dimensional(1D) nanomaterials allow the exquisite strain engineering with a broad tunability inaccessible to bulk or thin-film materials.Such capability enables unprecedented possibilities for probing intriguing physics and materials science in the 1-D limit.Among the techniques for introducing controlled strains in 1D materials,nanoimprinting with embossed substrates attracts increased attention due to its capability to parallelly form nanomaterials into wrinkled structures with controlled periodicities,amplitudes,orientations at large scale with nanoscale resolutions.Here,we systematically investigated the strain-engineered anisotropic optical properties in Te nanowires through introducing a controlled strain field using a resist-free thermally assisted nanoimprinting process.The magnitude of induced strains can be tuned by adjusting the imprinting pressure,the nanowire diameter,and the patterns on the substrates.The observed Raman spectra from the chiral-chain lattice of 1D Te reveal the strong lattice vibration response under the strain.Our results suggest the potential of 1D Te as a promising candidate for flexible electronics,deformable optoelectronics,and wearable sensors.The experimental platform can also enable the exquisite mechanical control in other nanomaterials using substrate-induced,on-demand,and controlled strains.
基金funded by the National Natural Science Foundation of China (11902056, 11632004, 11902053, and U1864208)the National Key Research and Development Program of China (2018YFC1105800)+7 种基金the National Science and Technology Major Project (2017-VII-0011-0106)the Key Program for International Science and Technology Cooperation Projects of the Ministry of Science and Technology of China (2016YFE0125900)the Key Project of Natural Science Foundation of CQ CSTC (cstc2017jcyj BX0063)Science and Technology Planning Project of Tianjin (20ZYJDJC00030)Key Program of Research and Development of Hebei Province (202030507040009)the Fund for Innovative Research Groups of Natural Science Foundation of Hebei Province (A2020202002)the Key Project of Natural Science Foundation of Tianjin (S20ZDF077)the China Postdoctoral Science Foundation funded project (2019M653334 and 2020M680842)。
文摘Previous experimental and computational results have confirmed that the thermal conductivity of a twodimensional(2D) material can be considerably affected by strain. Numerous attention has been paid to explore the relevant mechanisms. However, the strain effects on the interfacial thermal conductance(ITC) of 2D heterostructure have attracted little attention. Herein, the non-equilibrium molecular dynamics(NEMD) simulations were conducted to the graphene/hexagonal boron nitride(GR/h-BN) heterostructure to investigate the strain effects on the ITC. Three types of strains were considered, i.e., tensile strain, compressive strain, and shear strain.The results indicate that the strain can adjust the ITC for the GR/h-BN heterostructure effectively, and the strain loading direction also influences the ITC. Generally, the tensile strain reduces the ITC of the heterostructure, in addition to the BN-C system at small tensile strain;both the compressive strain and shear strain increase the ITC,especially at a small strain. For the NB-C system, it is more sensitive to the strain loading direction and the yx shear strain of 0.06 is the most effective way to strengthen the ITC. Our results also show that the out-of-plane deformation weakens the in-plane vibration of atoms, leading to a reduction of the interfacial thermal energy transport.
基金supported by the National Natural Science Foundation of China(Nos.92365203,52072168,51861145201,and 523B1010)the National Key Basic Research Program of the Ministry of Science and Technology of China(No.2021YFA1202901)the Natural Science Foundation of Jiangsu Province(No.BK20200341).
文摘Layered trihalides exhibit distinctive band structures and physical properties due to the sixfold coordinated 3d or 4d transition metal site and partially occupied d orbitals,holding great potential in condensed matter physics and advanced electronic applications.Prior research focused on trihalides with highly symmetric honeycomb-like structures,such as CrI3 andα-RuCl_(3),while the role of crystal anisotropy in trihalides remains elusive.In particular,the trihalide MoCl_(3) manifests strong in-plane crystal anisotropy with the largest difference in Mo–Mo interatomic distances.Research on such material is imperative to address the lack of investigations on the effect of anisotropy on the properties of trihalides.Herein,we demonstrated the anisotropy of MoCl_(3) through polarized Raman spectroscopy and further tuned the phonon frequency via strain engineering.We showed the Raman intensity exhibits twofold symmetry under parallel configuration and fourfold symmetry under perpendicular configuration with changing the polarization angle of incident light.Furthermore,we found that the phonon frequencies of MoCl_(3) decrease gradually and linearly with applying uniaxial tensile strain along the axis of symmetry in the MoCl_(3) crystal,while those frequencies increase with uniaxial tensile strain applied perpendicularly.Our results shed light on the manipulation of anisotropic light-matter interactions via strain engineering,and lay a foundation for further exploration of the anisotropy of trihalides and the modulation of their electronic,optical,and magnetic properties.
基金financial support from the National Natural Science Foundation of China(No.21975067)Fundamental Research Funds for the Central Universities from Hunan University。
文摘Two-dimensional(2D)materials have received extensive attention in the fields of electronics,optoelectronics,and magnetic devices attributed to their unique electronic structures and physical properties.The application of strain is a simple and effective strategy to change the lattice structure of 2D materials thus modulating their physical properties,which further facilitate their applications in carrier mobility transistor,magnetic sensor,single-photon emitter etc.In this short review,we focus on the strain applied via substrate engineering.Firstly,the relationship between the strain and physical properties has been summarized.Secondly,the methods for achieving substrate engineering-induced strain have been demonstrated.Finally,the latest applications of strained 2D materials have been introduced.In addition,the future challenges and development prospects of strain-modulated 2D materials have also been proposed.