Strain engineering serves as an effective approach for tuning the properties of transition metal oxides and their heterostructures. However, conventional epitaxial approaches are fundamentally constrained by the limit...Strain engineering serves as an effective approach for tuning the properties of transition metal oxides and their heterostructures. However, conventional epitaxial approaches are fundamentally constrained by the limited choice of substrates, which restricts the ability to achieve continuous strain modulation. The emergence of freestanding oxide thin films has significantly expanded the scope of strain manipulation, allowing the application of larger tensile strains and the induction of novel functionalities. Nevertheless, current freestanding film technologies face a critical limitation: strain modulation has so far been confined to tensile strain, while the application of compressive strain remains inaccessible. To overcome this challenge, we designed a symmetric tri-layer structure composed of clamping layer/nickelate/clamping layer, which enables modulation of the metal-insulator transition in freestanding Nd NiO_(3) and La NiO_(3) thin films under both tensile and compressive strain. This clamping-layermediated strain engineering approach can be readily generalized to other freestanding oxide systems, providing a versatile platform for manipulating the physical properties of freestanding thin films.展开更多
Lattice-strain engineering has demonstrated its capability to influence the electronic structure and catalytic performance of electrocatalysts.Herein,we present a facile method for inducing thermal strain in cobalt/mo...Lattice-strain engineering has demonstrated its capability to influence the electronic structure and catalytic performance of electrocatalysts.Herein,we present a facile method for inducing thermal strain in cobalt/molybdenum nitride rod-shaped structures(denoted Co/Mo_(2)N)via ammonia-assisted reduction,which effectively modulating the HER performance.The optimized Co/Mo_(2)N-500,characterized by 3%tensile lattice strain,demonstrates exceptional HER activity with lower overpotentials of140 mV and 184 mV at high current density of 1000 mA cm^(-2)in alkaline freshwater and seawater electrolytes,respectively.Co/Mo_(2)N also exhibits excellent long-term durability even at a high current density of 300 mA cm^(-2),surpassing its counterparts and benchmark Pt/C catalyst.Density functional theory calculations validate that the tensile strain optimizes the d-band states,water dissociation,and hydrogen adsorption kinetics of the strained Mo_(2)N in Co/Mo_(2)N,thereby improving its catalytic efficacy.This work provides valuable insights into controlling lattice strain to develop highly efficient electrocatalysts towards advanced electrocatalytic applications.展开更多
Flexible perovskite solar cells(fPSCs)have demonstrated commercial viability because of their promising lightness,flexibility,and low-cost advantages.However,in most applications,the fPSCs suffer from constant externa...Flexible perovskite solar cells(fPSCs)have demonstrated commercial viability because of their promising lightness,flexibility,and low-cost advantages.However,in most applications,the fPSCs suffer from constant external stress,such as being kept at a convex bending state,imposing external stress on the brittle perovskite films and causing the fPSCs long-term stability problems.Overcoming these issues is vital.Herein,we propose an effective way to enhance the stability of the fPSCs under convex bending by modulating the residual stress of perovskite film for the first time.Specifically,we have carefully designed a synergistic strain engineering to toughen the perovskite films by introducing 1-butyl-3-methylimidazolium tetrafluoroborate,citric acid,and a novel cross-linker,5-(1,2-dithiolan-3-yl)pentanoate into perovskite films simultaneously.Besides passivating the perovskite films,the multiple additives effectively convert the residual stress within the perovskite films from tensile to compressive type to alleviate the detrimental impact of bending on the flexible perovskite films.As a result,the optimal efficiencies of triple-additive modified fPSCs have achieved 22.19%(0.06 cm^(2))and 19.44%(1.02 cm^(2)).More importantly,the strategy could significantly improve the stability of the perovskite films and fPSCs at a convex bending state.Our approach is inductive for the future practical field applications of high-performance fPSCs.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 investigate the strain in various Ge-on-insulator （GeOI） micro-structures induced by three phase-change maferials （PCMs） （Ge2Sb2Te5, Sb2Te3, GeTe） deposited. The PCMs could change the phase from amorphous sta...We investigate the strain in various Ge-on-insulator （GeOI） micro-structures induced by three phase-change maferials （PCMs） （Ge2Sb2Te5, Sb2Te3, GeTe） deposited. The PCMs could change the phase from amorphous state to polycrystalline state with a low temperature thermal annealing, resulting in an intrinsic contraction in the PCM films. Raman spectroscopy analysis is performed to compare the strain induced in the GeOI micro- structures by various PCMs. By comparison, Sb2 Tea could induce the largest amount of tensile strain in the GeOI micro-structures after the low temperature annealing. Based on the strain calculated from the Raman peak shifts, finite element numerical simulation is performed to calculate the strain-induced electron mobility enhancement for Ge n-MOSFETs with PCM liner stressors. With the adoption of Sb2 Te3 liner stressor, 22% electron mobility enhancement at Xinv=1×10^13cm^-2 could be achieved, suggesting that PCM especially Sb2 Te3 liner stressor is a promising technique for the performance enhancement of Ge MOSFETs.展开更多
Reversible control of surface wettability has wide applications in lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a graphene sheet as a sam- ple material and molecular dynamic simulations, ...Reversible control of surface wettability has wide applications in lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a graphene sheet as a sam- ple material and molecular dynamic simulations, we demon- strate that strain engineering can serve as an effective way to control the surface wettability. The contact angles 0 of water droplets on a graphene vary from 72.5° to 106° under biaxial strains ranging from -10% to 10% that are applied on the graphene layer. For an intrinsic hydrophilic surface （at zero strain）, the variation of 0 upon the applied strains is more sensitive, i.e., from 0° to 74.8°. Overall the cosines of the contact angles exhibit a linear relation with respect to the strains. In light of the inherent dependence of the contact an- gle on liquid-solid interfacial energy, we develop an analytic model to show the cos 0 as a linear function of the adsorption energy Eads of a single water molecule over the substrate sur- face. This model agrees with our molecular dynamic results very well. Together with the linear dependence of Eads on bi- axial strains, we can thus understand the effect of strains on the surface wettability. Thanks to the ease of reversibly ap- plying mechanical strains in micro/nano-electromechanical systems, we believe that strain engineering can be a promis- ing means to achieve the reversibly control of surface wetta- bility.展开更多
Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure tr...Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.展开更多
Strain engineering of two-dimensional(2D)material interfaces represents a powerful strategy for enhanc-ing the electrocatalytic activity of water splitting.However,maintaining catalytic stability under various harsh c...Strain engineering of two-dimensional(2D)material interfaces represents a powerful strategy for enhanc-ing the electrocatalytic activity of water splitting.However,maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge.The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets(NSs)derived from metal organic frameworks(lr@NiO/C_(BDc)),which displays a high activity and stability under all pH conditions,and even a change of only 1%in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions.Through combined experimental and computational studies,we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/CBDC catalyst,arising from its increased Ir and Ni vacancy formation energies,and hence suppressing its leach-ing.Moreover,strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by op-timizing its electronic structure and coordination environment.This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable electrocatalysts.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
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
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
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
We report here a theoretical study on 34 transition metal doped two-dimensional GaPS_(4) catalysts,denoted as transition metal transition metal@VS-GaPS_(4).Among them,the Pt@V_(S1)-GaPS_(4) single-atom catalyst is fou...We report here a theoretical study on 34 transition metal doped two-dimensional GaPS_(4) catalysts,denoted as transition metal transition metal@VS-GaPS_(4).Among them,the Pt@V_(S1)-GaPS_(4) single-atom catalyst is found to be stable with an ORR/OER overpotential of 0.59/0.41 V.Under the guidance of a volcano map,further biaxial strain engineering is adopted to tune the activity of Pt@V_(S1)-GaPS_(4) to the top of the volcano.The overpotentials of the OER/ORR are decreased to 0.37/0.33 V by applying a 3%tensile strain.Our results prove that Pt@V_(S1)-GaPS_(4) is an excellent candidate for OER/ORR bifunctional electro-catalysis.Moreover,bond angles and the highest occupied orbitals of the doped transition metal atoms can be used as descriptors to explain the underlying strain tunability mechanism.The machine learning method further predicts that the number of d electrons,the bond length and electronegativity are three main descriptors to determine the catalytic activity.展开更多
While magnetic skyrmions in perpendicular magnetic anisotropy(PMA)systems are extensively studied,their realization in in-plane magnetic anisotropy(IMA)materials remains largely unexplored.Here,we demonstrate that Jan...While magnetic skyrmions in perpendicular magnetic anisotropy(PMA)systems are extensively studied,their realization in in-plane magnetic anisotropy(IMA)materials remains largely unexplored.Here,we demonstrate that Janus NbXTe(X=Se,S)monolayers host spontaneous tilted chiral textures,stabilized by substantial Dzyaloshinskii-Moriya interaction(DMI)(0.80 meV for NbSeTe,0.59 meV for NbSTe)and intrinsic IMA.Combining first-principles calculations and atomistic spin dynamics simulations,we establish that perpendicular fields and biaxial strain independently reshape the energy landscape by tuning the competition among exchange,DMI,and anisotropy.Remarkably,while both materials spontaneously host skyrmions at zero field,NbSTe exhibits a superior field response,enabling multi-skyrmion nucleation at~0.2 T compared to~0.8 T for NbSeTe.Moreover,NbSTe sustains stability under 6%tensile strain,whereas NbSeTe undergoes topological degradation into chain-like textures.This work elucidates the stabilization mechanisms in two-dimensional(2D)IMA systems and identifies NbSTe as a robust candidate for low-power spintronic applications.展开更多
The potential of microalgae as a biological resource for carbon capture,utilization,and storage(CCUS)has been extensively discussed.Although genetic engineering methods have been employed to improve microalgal phenoty...The potential of microalgae as a biological resource for carbon capture,utilization,and storage(CCUS)has been extensively discussed.Although genetic engineering methods have been employed to improve microalgal phenotypes,they often face challenges related to public concerns regarding genetically modified organisms.By contrast,adaptive laboratory evolution(ALE)and microbiome optimization have emerged as promising non-genetic modification strategies,with notable success in bacterial models.In microalgae,ALE has been employed to improve resilience against varying environmental and stress factors and increase carbon capture efficiency,and for the production of valuable bioproducts through gradual accumulation of beneficial mutations following manual or automated selection.Furthermore,advancements in the understanding of microbial symbiotic relationships in the phycosphere have facilitated microbiome optimization in microalgal cultivation systems,significantly improving their functionality and productivity.In this study,we provide a comprehensive overview of the latest advancements in ALE and microbiome optimization of microalgae for CCUS across different carbon emission scenarios,including flue gas,biogas,wastewater,and landfill leachate.We further discuss the current challenges and future directions for the integration of ALE with microbiome optimization,focusing on the potential synergies of these methodologies.Overall,ALE and microbiome optimization are promising approaches to direct microalgae for environmental and industrial CCUS applications,thereby reducing global carbon emissions and addressing climate change challenges.展开更多
Hafnium oxide(HfO_(2))-based ferroelectric materials have been widely applied in logic and memory devices due to their favorable ferroelectric and dielectric properties.However,the weak ferroelectric polarization of p...Hafnium oxide(HfO_(2))-based ferroelectric materials have been widely applied in logic and memory devices due to their favorable ferroelectric and dielectric properties.However,the weak ferroelectric polarization of pure HfO_(2)limits its application potential in advanced ferroelectric devices.Here,an ultrahigh remanent polarization is successfully achieved in the Ce-doped HfO_(2)films through a chemical negative strain due to the biaxial strain engineering strategy.The Ce-doped HfO_(2)films with regulated ions concentrations are fabricated on crystallographic-oriented substrates,and the effects of substrate-induced strain on the film growth were systematically investigated.Notably,the Ce-doped HfO_(2)films grown on(011)oriented substrates exhibit an excellent remanent polarization(2P_(t)=102.1µC/cm^(2),representing the highest value reported for HfO_(2)-based ferroelectrics,along with the outstanding fatigue resistance(<10%degradation after 107 switching cycles).This work provides a novel strategy for developing high-performance HfO_(2)-based ferroelectric materials through strain engineering,laying a critical foundation for their applications in non-volatile memory technologies.展开更多
The recent transport measurements of La_(3)Ni_(2)O_(7)uncovered a“right-triangle”shape of the superconducting dome in the pressure-temperature(P-T)phase diagram.Motivated by this,we perform theoretical first-princip...The recent transport measurements of La_(3)Ni_(2)O_(7)uncovered a“right-triangle”shape of the superconducting dome in the pressure-temperature(P-T)phase diagram.Motivated by this,we perform theoretical first-principles studies of La_(3)Ni_(2)O_(7)with the pressure ranging from 0 to 100 GPa.Notably,we reveal a pressure dependence of the Ni-d_(z^(2))electron density at the Fermi energy(n_(z)^(E_(F)))that highly coincides with such shape.On this basis,we further explore the electronic structure under uniaxial stress.By tracking the stress response of n_(z)^(E_(F)),we propose that superconductivity can be achieved by applying only ~2GPa of compression along the c axis.The idea is further exemplified from the perspectives of lattice distortion,band structure,Fermi surface and superconducting phase coherence.We also discuss the possible charge modulation under the stress and provide an insight into the relation between nz E Fand the superconducting T_(c)in La_(3)Ni_(2)O_(7)system.Our study provides new routes to the search of high-T_(c)superconductors in future experiments.展开更多
Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study el...Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.展开更多
Back-contacted perovskite solar cells(PSCs)have been demonstrated with merits of low material cost and weak ion migration,while the inferior buried surface restricts their performance and bifacial response.Herein,poly...Back-contacted perovskite solar cells(PSCs)have been demonstrated with merits of low material cost and weak ion migration,while the inferior buried surface restricts their performance and bifacial response.Herein,polyvinylidene fluoride(PVDF)with similar thermal expansion coefficient to perovskites and low tensile modulus is introduced at the substrate/crystal interface to release interface lattice strain and enhance crystallinity.Besides,PVDF can release free fluoride ions to interact with bare Pb^(2+)ions,reducing interface charge trap density and nonradiative recombination.As a result,an impressive efficiency of 13.37%is obtained,setting a new efficiency benchmark for back-contacted PSCs.Moreover,the PVDF-modified devices retain 100%of their initial efficiency after 1,200 h of maximum power point tracking at 60℃.Finally,a high bifaciality factor of 0.96 is obtained,leading to obvious increase of power output under simulated circumstance with reflected light.展开更多
MoTe_(2) has emerged as a promising candidate in the field of integrated circuits,memristive devices,and catalysts,owing to its polymorphic nature across different phases.Experimentally,strain engineering has been dem...MoTe_(2) has emerged as a promising candidate in the field of integrated circuits,memristive devices,and catalysts,owing to its polymorphic nature across different phases.Experimentally,strain engineering has been demonstrated as an effective approach for manipulating the phase transition of MoTe_(2),but the mechanism remains unclear.The strain-dependent phase transition and its micro-mechanisms have been investigated based on first principle calculations.As demonstrated,critical strain and phase transition path from H→T'phases are strongly governed by the applied strain's orientation,magnitude,and triaxiality.At the atomic level,nonzero movements of Te atoms within the phase transition domain with mechanical unloading have been clarified,together with an advanced understanding on the impact of strain on Te-vacancies migration.These insights advanced the knowledge of MoTe_(2) phase transition behavior and demonstrated the large space to explore potential applications through strain,defect,and phase engineering.展开更多
基金supported by the National Key Research and Development Program of China (Grant No.2023YFA1406404)the National Natural Science Foundation of China (Grant Nos.12504152,52572144,12374094,and 12074365)+5 种基金China Postdoctoral Science Foundation (Grant No.2024M763130)the China Postdoctoral Science Foundation-Anhui joint Support Program (Grant No.2024T007AH)the Fundamental Research Funds for the Central Universities(Grant No.WK9990000158)Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-084)Innovation Program for Quantum Science and Technology (Grant No.2024ZD0301300)Anhui Provincial Natural Science Foundation (Grant No.2308085MA15)。
文摘Strain engineering serves as an effective approach for tuning the properties of transition metal oxides and their heterostructures. However, conventional epitaxial approaches are fundamentally constrained by the limited choice of substrates, which restricts the ability to achieve continuous strain modulation. The emergence of freestanding oxide thin films has significantly expanded the scope of strain manipulation, allowing the application of larger tensile strains and the induction of novel functionalities. Nevertheless, current freestanding film technologies face a critical limitation: strain modulation has so far been confined to tensile strain, while the application of compressive strain remains inaccessible. To overcome this challenge, we designed a symmetric tri-layer structure composed of clamping layer/nickelate/clamping layer, which enables modulation of the metal-insulator transition in freestanding Nd NiO_(3) and La NiO_(3) thin films under both tensile and compressive strain. This clamping-layermediated strain engineering approach can be readily generalized to other freestanding oxide systems, providing a versatile platform for manipulating the physical properties of freestanding thin films.
基金supported by the Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy(2020CB1007)Fundamental Research Funds for the Central Universities and Guangxi Key Laboratory of Information Materials and Guilin University of Electronic Technology,China(231002-K)+4 种基金Natural Science Foundation of Guangxi Zhuang Autonomous Region(2022GXNSFAA035467)Guangxi Science and Technology Program(Guike AD21220067)National Natural Science Foundation of China(22369002)Nationally Funded Postdoctoral Researcher Program(GZC20230756)China Postdoctoral Science Foundation(2024M750858)。
文摘Lattice-strain engineering has demonstrated its capability to influence the electronic structure and catalytic performance of electrocatalysts.Herein,we present a facile method for inducing thermal strain in cobalt/molybdenum nitride rod-shaped structures(denoted Co/Mo_(2)N)via ammonia-assisted reduction,which effectively modulating the HER performance.The optimized Co/Mo_(2)N-500,characterized by 3%tensile lattice strain,demonstrates exceptional HER activity with lower overpotentials of140 mV and 184 mV at high current density of 1000 mA cm^(-2)in alkaline freshwater and seawater electrolytes,respectively.Co/Mo_(2)N also exhibits excellent long-term durability even at a high current density of 300 mA cm^(-2),surpassing its counterparts and benchmark Pt/C catalyst.Density functional theory calculations validate that the tensile strain optimizes the d-band states,water dissociation,and hydrogen adsorption kinetics of the strained Mo_(2)N in Co/Mo_(2)N,thereby improving its catalytic efficacy.This work provides valuable insights into controlling lattice strain to develop highly efficient electrocatalysts towards advanced electrocatalytic applications.
基金supported by the National Key R&D Program of China(2022YFE0118400)the National Natural Science Foundation of China(6217520)+1 种基金the Science and Technology Project of Fujian Province of China(2021H6018)the Natural Science Foundation of Fujian Province of China(2021J06009)。
文摘Flexible perovskite solar cells(fPSCs)have demonstrated commercial viability because of their promising lightness,flexibility,and low-cost advantages.However,in most applications,the fPSCs suffer from constant external stress,such as being kept at a convex bending state,imposing external stress on the brittle perovskite films and causing the fPSCs long-term stability problems.Overcoming these issues is vital.Herein,we propose an effective way to enhance the stability of the fPSCs under convex bending by modulating the residual stress of perovskite film for the first time.Specifically,we have carefully designed a synergistic strain engineering to toughen the perovskite films by introducing 1-butyl-3-methylimidazolium tetrafluoroborate,citric acid,and a novel cross-linker,5-(1,2-dithiolan-3-yl)pentanoate into perovskite films simultaneously.Besides passivating the perovskite films,the multiple additives effectively convert the residual stress within the perovskite films from tensile to compressive type to alleviate the detrimental impact of bending on the flexible perovskite films.As a result,the optimal efficiencies of triple-additive modified fPSCs have achieved 22.19%(0.06 cm^(2))and 19.44%(1.02 cm^(2)).More importantly,the strategy could significantly improve the stability of the perovskite films and fPSCs at a convex bending state.Our approach is inductive for the future practical field applications of high-performance fPSCs.
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Supported by the National Natural Science Foundation of China under Grant Nos 61376097,61504120U1609213,the Zhejiang Provincial Natural Science Foundation of China under Grant No LR14F040001the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20130091110025
文摘We investigate the strain in various Ge-on-insulator （GeOI） micro-structures induced by three phase-change maferials （PCMs） （Ge2Sb2Te5, Sb2Te3, GeTe） deposited. The PCMs could change the phase from amorphous state to polycrystalline state with a low temperature thermal annealing, resulting in an intrinsic contraction in the PCM films. Raman spectroscopy analysis is performed to compare the strain induced in the GeOI micro- structures by various PCMs. By comparison, Sb2 Tea could induce the largest amount of tensile strain in the GeOI micro-structures after the low temperature annealing. Based on the strain calculated from the Raman peak shifts, finite element numerical simulation is performed to calculate the strain-induced electron mobility enhancement for Ge n-MOSFETs with PCM liner stressors. With the adoption of Sb2 Te3 liner stressor, 22% electron mobility enhancement at Xinv=1×10^13cm^-2 could be achieved, suggesting that PCM especially Sb2 Te3 liner stressor is a promising technique for the performance enhancement of Ge MOSFETs.
基金supported by the National Natural Science Foundation of China(11172149)the financial support from the IBM World Community Grid project "Computing for Clean Water"+2 种基金the Boeing-Tsinghua Joint Research Project "New Air Filtration Materials"grant 2012 from engineering faculty of Monash Universitysupported by an award under the Merit Allocation Scheme on the Australia NCI National Facility at the ANU
文摘Reversible control of surface wettability has wide applications in lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a graphene sheet as a sam- ple material and molecular dynamic simulations, we demon- strate that strain engineering can serve as an effective way to control the surface wettability. The contact angles 0 of water droplets on a graphene vary from 72.5° to 106° under biaxial strains ranging from -10% to 10% that are applied on the graphene layer. For an intrinsic hydrophilic surface （at zero strain）, the variation of 0 upon the applied strains is more sensitive, i.e., from 0° to 74.8°. Overall the cosines of the contact angles exhibit a linear relation with respect to the strains. In light of the inherent dependence of the contact an- gle on liquid-solid interfacial energy, we develop an analytic model to show the cos 0 as a linear function of the adsorption energy Eads of a single water molecule over the substrate sur- face. This model agrees with our molecular dynamic results very well. Together with the linear dependence of Eads on bi- axial strains, we can thus understand the effect of strains on the surface wettability. Thanks to the ease of reversibly ap- plying mechanical strains in micro/nano-electromechanical systems, we believe that strain engineering can be a promis- ing means to achieve the reversibly control of surface wetta- bility.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61264008,61574080 and 61505085
文摘Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.
基金Hainan Province Science and Technology Special Fund(Nos.ZDYF2021SHFZ068 and ZDKJ2021029)National Natural Science Foundation of China(No.52262014)+1 种基金Hainan Provincial Natural Science Foundation of China(No.823CXTD376)Youth Foundation of Hainan Province(No.221QN0898).
文摘Strain engineering of two-dimensional(2D)material interfaces represents a powerful strategy for enhanc-ing the electrocatalytic activity of water splitting.However,maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge.The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets(NSs)derived from metal organic frameworks(lr@NiO/C_(BDc)),which displays a high activity and stability under all pH conditions,and even a change of only 1%in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions.Through combined experimental and computational studies,we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/CBDC catalyst,arising from its increased Ir and Ni vacancy formation energies,and hence suppressing its leach-ing.Moreover,strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by op-timizing its electronic structure and coordination environment.This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable electrocatalysts.
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supported by the National Natural Science Foundation of China(Grant No.12164009)which is received by Xuefei Liu+1 种基金the Guizhou Science and Technology Foundation-ZK[2022]General 308,which is received by Xuefei Liuand the Graduate Research Fund Project of Guizhou Province(YJSKYJJ[2021]088),which is received by Tianyun Liu.
文摘We report here a theoretical study on 34 transition metal doped two-dimensional GaPS_(4) catalysts,denoted as transition metal transition metal@VS-GaPS_(4).Among them,the Pt@V_(S1)-GaPS_(4) single-atom catalyst is found to be stable with an ORR/OER overpotential of 0.59/0.41 V.Under the guidance of a volcano map,further biaxial strain engineering is adopted to tune the activity of Pt@V_(S1)-GaPS_(4) to the top of the volcano.The overpotentials of the OER/ORR are decreased to 0.37/0.33 V by applying a 3%tensile strain.Our results prove that Pt@V_(S1)-GaPS_(4) is an excellent candidate for OER/ORR bifunctional electro-catalysis.Moreover,bond angles and the highest occupied orbitals of the doped transition metal atoms can be used as descriptors to explain the underlying strain tunability mechanism.The machine learning method further predicts that the number of d electrons,the bond length and electronegativity are three main descriptors to determine the catalytic activity.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.SZR2536)。
文摘While magnetic skyrmions in perpendicular magnetic anisotropy(PMA)systems are extensively studied,their realization in in-plane magnetic anisotropy(IMA)materials remains largely unexplored.Here,we demonstrate that Janus NbXTe(X=Se,S)monolayers host spontaneous tilted chiral textures,stabilized by substantial Dzyaloshinskii-Moriya interaction(DMI)(0.80 meV for NbSeTe,0.59 meV for NbSTe)and intrinsic IMA.Combining first-principles calculations and atomistic spin dynamics simulations,we establish that perpendicular fields and biaxial strain independently reshape the energy landscape by tuning the competition among exchange,DMI,and anisotropy.Remarkably,while both materials spontaneously host skyrmions at zero field,NbSTe exhibits a superior field response,enabling multi-skyrmion nucleation at~0.2 T compared to~0.8 T for NbSeTe.Moreover,NbSTe sustains stability under 6%tensile strain,whereas NbSeTe undergoes topological degradation into chain-like textures.This work elucidates the stabilization mechanisms in two-dimensional(2D)IMA systems and identifies NbSTe as a robust candidate for low-power spintronic applications.
基金supported by the James Albrecht Graduate Student Fellowship for Z.He,and J.Wang at the Institute of Marine and Environmental Technology(IMET),the University System of Maryland and the DOE Office of Fossil Energy and Carbon Management(FE-0031914 and FE-0032188).
文摘The potential of microalgae as a biological resource for carbon capture,utilization,and storage(CCUS)has been extensively discussed.Although genetic engineering methods have been employed to improve microalgal phenotypes,they often face challenges related to public concerns regarding genetically modified organisms.By contrast,adaptive laboratory evolution(ALE)and microbiome optimization have emerged as promising non-genetic modification strategies,with notable success in bacterial models.In microalgae,ALE has been employed to improve resilience against varying environmental and stress factors and increase carbon capture efficiency,and for the production of valuable bioproducts through gradual accumulation of beneficial mutations following manual or automated selection.Furthermore,advancements in the understanding of microbial symbiotic relationships in the phycosphere have facilitated microbiome optimization in microalgal cultivation systems,significantly improving their functionality and productivity.In this study,we provide a comprehensive overview of the latest advancements in ALE and microbiome optimization of microalgae for CCUS across different carbon emission scenarios,including flue gas,biogas,wastewater,and landfill leachate.We further discuss the current challenges and future directions for the integration of ALE with microbiome optimization,focusing on the potential synergies of these methodologies.Overall,ALE and microbiome optimization are promising approaches to direct microalgae for environmental and industrial CCUS applications,thereby reducing global carbon emissions and addressing climate change challenges.
基金the National Natural Science Foundation of China(22371013,92263205)the National Key Research and Development Program of China(2018YFA0703700)+3 种基金the Fundamental Research Funds for the Central Universities(FRF-IDRY-19-007 and FRF-TP-19-055A2Z)the National Program for Support of Top-notch Young Professionalsthe Young Elite Scientists Sponsorship Program by CAST(2019-2021QNRC)the"Xiaomi Young Scholar"Funding Project。
文摘Hafnium oxide(HfO_(2))-based ferroelectric materials have been widely applied in logic and memory devices due to their favorable ferroelectric and dielectric properties.However,the weak ferroelectric polarization of pure HfO_(2)limits its application potential in advanced ferroelectric devices.Here,an ultrahigh remanent polarization is successfully achieved in the Ce-doped HfO_(2)films through a chemical negative strain due to the biaxial strain engineering strategy.The Ce-doped HfO_(2)films with regulated ions concentrations are fabricated on crystallographic-oriented substrates,and the effects of substrate-induced strain on the film growth were systematically investigated.Notably,the Ce-doped HfO_(2)films grown on(011)oriented substrates exhibit an excellent remanent polarization(2P_(t)=102.1µC/cm^(2),representing the highest value reported for HfO_(2)-based ferroelectrics,along with the outstanding fatigue resistance(<10%degradation after 107 switching cycles).This work provides a novel strategy for developing high-performance HfO_(2)-based ferroelectric materials through strain engineering,laying a critical foundation for their applications in non-volatile memory technologies.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1402304,and 2022YFA1402802)the National Natural Science Foundation of China(Grant Nos.12122405,52072188,12274169,12494591,and 92165204)+4 种基金the Program for Science and Technology Innovation Team in Zhejiang(Grant No.2021R01004)the Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)the Fundamental Research Funds for the Central Universities(Grant Nos.xzy022023011,and xhj03202101404)the Research Center for Magnetoelectric Physics of Guangdong Province(Grant No.2024B0303390001)the Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDXZ2401010)。
文摘The recent transport measurements of La_(3)Ni_(2)O_(7)uncovered a“right-triangle”shape of the superconducting dome in the pressure-temperature(P-T)phase diagram.Motivated by this,we perform theoretical first-principles studies of La_(3)Ni_(2)O_(7)with the pressure ranging from 0 to 100 GPa.Notably,we reveal a pressure dependence of the Ni-d_(z^(2))electron density at the Fermi energy(n_(z)^(E_(F)))that highly coincides with such shape.On this basis,we further explore the electronic structure under uniaxial stress.By tracking the stress response of n_(z)^(E_(F)),we propose that superconductivity can be achieved by applying only ~2GPa of compression along the c axis.The idea is further exemplified from the perspectives of lattice distortion,band structure,Fermi surface and superconducting phase coherence.We also discuss the possible charge modulation under the stress and provide an insight into the relation between nz E Fand the superconducting T_(c)in La_(3)Ni_(2)O_(7)system.Our study provides new routes to the search of high-T_(c)superconductors in future experiments.
基金financial support from NSF ExpandQISE program.The synthesis of tellurene was supported by NSF under grant no.CMMI-2046936supports from Purdue Research Foundation.
文摘Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.
基金economically supported by the National Natural Science Foundation of China(62474102)Key R&D Program of Shandong Province,China(2024CXGC010302)。
文摘Back-contacted perovskite solar cells(PSCs)have been demonstrated with merits of low material cost and weak ion migration,while the inferior buried surface restricts their performance and bifacial response.Herein,polyvinylidene fluoride(PVDF)with similar thermal expansion coefficient to perovskites and low tensile modulus is introduced at the substrate/crystal interface to release interface lattice strain and enhance crystallinity.Besides,PVDF can release free fluoride ions to interact with bare Pb^(2+)ions,reducing interface charge trap density and nonradiative recombination.As a result,an impressive efficiency of 13.37%is obtained,setting a new efficiency benchmark for back-contacted PSCs.Moreover,the PVDF-modified devices retain 100%of their initial efficiency after 1,200 h of maximum power point tracking at 60℃.Finally,a high bifaciality factor of 0.96 is obtained,leading to obvious increase of power output under simulated circumstance with reflected light.
基金supported by NSFC Grants(Nos.12032004,11872114,and 11502150)Natural Science Foundation of Hebei Province of China(No.A2016210060)+1 种基金The Higher Education Youth Talents Program of Hebei Province of China(No.BJ2017052)Science and Technology Project of Hebei Education Department(No.QN2020204)。
文摘MoTe_(2) has emerged as a promising candidate in the field of integrated circuits,memristive devices,and catalysts,owing to its polymorphic nature across different phases.Experimentally,strain engineering has been demonstrated as an effective approach for manipulating the phase transition of MoTe_(2),but the mechanism remains unclear.The strain-dependent phase transition and its micro-mechanisms have been investigated based on first principle calculations.As demonstrated,critical strain and phase transition path from H→T'phases are strongly governed by the applied strain's orientation,magnitude,and triaxiality.At the atomic level,nonzero movements of Te atoms within the phase transition domain with mechanical unloading have been clarified,together with an advanced understanding on the impact of strain on Te-vacancies migration.These insights advanced the knowledge of MoTe_(2) phase transition behavior and demonstrated the large space to explore potential applications through strain,defect,and phase engineering.
