Elastic electronics are increasingly prevalent in information storage,smart sensing and health monitoring due to their softness,stretchability and portability.Wearable electronic devices should possess elasticity and ...Elastic electronics are increasingly prevalent in information storage,smart sensing and health monitoring due to their softness,stretchability and portability.Wearable electronic devices should possess elasticity and stretchability that align with biological tissues.Specifically,their materials should be capable of elastic strain up to 50–80%,while the devices themselves must maintain electric stability under strains that accommodate body movements[1].展开更多
Ferroelectrics(FEs)have shown great potential in sensors,actuators,and electrocaloric cooling due to their direct cross-couplings between electric polarization and mechanical,thermal,and dielectric properties[1−3]Comp...Ferroelectrics(FEs)have shown great potential in sensors,actuators,and electrocaloric cooling due to their direct cross-couplings between electric polarization and mechanical,thermal,and dielectric properties[1−3]Compared with oxide FEs,polymer FEs possess good flexible and shape adaptability,making them promising candidates for flexible electronics and biocompatible devices[4].展开更多
Perovskite optoelectronic devices,capitalizing on the exceptional light-matter interaction and semiconductor properties of perovskite materials,have emerged as transformative platforms for energy conversion,informatio...Perovskite optoelectronic devices,capitalizing on the exceptional light-matter interaction and semiconductor properties of perovskite materials,have emerged as transformative platforms for energy conversion,information storage,and photonic technologies.While material innovations and device engineering breakthroughs have propelled remarkable advancements,persistent challenges in operational stability,scalable manufacturing,and batch reproducibility continue to hinder commercial implementation.Recently,molecular ferroelectrics(MOFEs),as a class of materials characterized by polar crystal structures and switchable spontaneous polarization(P_(s)),offer novel pathways to regulate high-efficiency and stable perovskite optoelectronic devices.Here,we systematically review the application of MOFEs into diverse perovskite optoelectronic systems,emphasizing the synergistic effect between P_(s)and optoelectronic properties.We analyze MOFEs-based photodetectors spanning self-powered,X-ray,and polarized-light detectors,detailing how P_(s)and synergistic physical effects optimize device performance.For photovoltaic applications,we elucidate polarizationdriven performance enhancement mechanisms in perovskite solar cells(PSCs),including built-in field amplification,defect passivation,and stability improvement.Furthermore,we envisage the emerging applications of MOFEs in optoelectronic fields such as non-volatile memory,neuromorphic computing,and optical communication.Overall,this review furnishes valuable insights into optoelectronics and future energy.展开更多
The performance optimization of materials is an eternal theme and challenge in scientific research,which is reflected in ferroelectric filed to two hot topics of enhancing Curie temperature(TC)and functional versatili...The performance optimization of materials is an eternal theme and challenge in scientific research,which is reflected in ferroelectric filed to two hot topics of enhancing Curie temperature(TC)and functional versatility.The former one vitally determines ferroelectric operational temperature range while the latter would open up new application possibilities.Effective chemical modification or doping strategies on A-site and X-site components have been successfully developed in hybrid organic-inorganic perovskite(HOIP)ferroelectrics,however,the important role of adjusting B-site ions has long been overlooked.Here,we have implemented regulation on the ion radius of the B-site component to successfully obtain two new HOIP ferroelectrics(3-pyrrolinium)BBr_(3)(B=Mn and Ni).Compared to parent(3-pyrrolinium)CdBr_(3),the TC(△T=99 K)was significantly optimized by replacing the Cd^(2+)with smaller Mn^(2+)or Ni^(2+)ions.More strikingly,the introduction of Mn^(2+)and Ni^(2+)ions with octahedral coordination bring out intriguing red emission and magnetism respectively,making the multifunctional integration in a single material for multiple uses.This work provides a feasible strategy for performance optimizing of HOIP ferroelectrics,and would shed light for constructing multifunctional ferroelectrics.展开更多
Molecular ferroelectrics have attracted much attention because of their excellent piezoelectricity,mechanical workability,and second harmonic effect.Here,we successfully prepared two molecular ferroelectrics[1,5-3.2.2...Molecular ferroelectrics have attracted much attention because of their excellent piezoelectricity,mechanical workability,and second harmonic effect.Here,we successfully prepared two molecular ferroelectrics[1,5-3.2.2-Hdabcn]X(X=ClO_(4)^(-),1;ReO_(4)^(-),2)by reactions of a quasi-spherical amine 1,5-diazabicycle[3.2.2]nonane(1.5-3.2.2-dabcn)with HX aqueous solution.Compounds 1 and 2 undergo hightemperature phase transitions at 381 K(1)and 396 K(2).Before and after the phase transition,they crystallize in the polar point group mm2,and the centrosymmetric point groups mmm and 4/mmm,respectively.According to Aizu rules,these two compounds experience mmm Fmm2 and 4/mmm Fmm2 type ferroelectric phase transitions,respectively.The ferroelectricity of both compounds is well expressed in their polycrystalline film at room temperature with low coercive voltages of 13 V for 1 and 25 V for 2.Using piezoelectric force microscopy(PFM),the 180°anti-parallel ferroelectric domains and the reversible polarization switching can be clearly observed in 1 and 2.This high-temperature molecular ferroelectric material has great application potential in flexible materials,biomechanics,intelligent wearables and other fields.展开更多
Advanced lead-free energy storage ceramics play an indispensable role in next-generation pulse power capacitors market.Here,an ultrahigh energy storage density of~13.8 J cm^(-3)and a large efficiency of~82.4%are achie...Advanced lead-free energy storage ceramics play an indispensable role in next-generation pulse power capacitors market.Here,an ultrahigh energy storage density of~13.8 J cm^(-3)and a large efficiency of~82.4%are achieved in high-entropy lead-free relaxor ferroelectrics by increasing configuration entropy,named high-entropy strategy,realizing nearly ten times growth of energy storage density compared with low-entropy material.Evolution of energy storage performance and domain structure with increasing configuration entropy is systematically revealed for the first time.The achievement of excellent energy storage properties should be attributed to the enhanced random field,decreased nanodomain size,strong multiple local distortions,and improved breakdown field.Furthermore,the excellent frequency and fatigue stability as well as charge/discharge properties with superior thermal stability are also realized.The significantly enhanced comprehensive energy storage performance by increasing configuration entropy demonstrates that high entropy is an effective but convenient strategy to design new high-performance dielectrics,promoting the development of advanced capacitors.展开更多
Two-dimensional （2D） materials, such as graphene and MoS2 related transition metal dichalcogenides （TMDC）, have attracted much attention for their potential applications. Ferroelectrics, one of the special and tra...Two-dimensional （2D） materials, such as graphene and MoS2 related transition metal dichalcogenides （TMDC）, have attracted much attention for their potential applications. Ferroelectrics, one of the special and traditional dielectric materials, possess a spontaneous electric polarization that can be reversed by the application of an external electric field. In recent years, a new type of device, combining 2D materials with ferroelectrics, has been fabricated. Many novel devices have been fabricated, such as low power consumption memory devices, highly sensitive photo-transistors, etc. using this technique of hybrid systems incorporating ferroelectrics and 2D materials. This paper reviews two types of devices based on field effect transistor （FET） structures with ferroelectric gate dielectric construction （termed FeFET）. One type of device is for logic applications, such as a graphene and TMDC FeFET for fabricating memory units. Another device is for optoelectric applications, such as high performance phototransistors using a graphene p-n junction. Finally, we discuss the prospects for future applications of 2D material FeFET.展开更多
The electrocaloric effect of the model ferroelectric BaTiO3was investigated using phenomenological theory. The results indicate that the applied electric field strength is a key factor for the induced electrocaloric r...The electrocaloric effect of the model ferroelectric BaTiO3was investigated using phenomenological theory. The results indicate that the applied electric field strength is a key factor for the induced electrocaloric response and there are two distinguishing electrocaloric responses. When a moderate electric field is applied, the electrocaloric temperature variation is small but the electrocaloric strength is high. In contrast, the electrocaloric temperature variation is large but electrocaloric strength is low when a very high electric field is applied. These results are consistent with the experimental observations on BaTiO3based bulk and thin film ferroelectric materials.展开更多
Ferroelectric semiconductors have sparked growing attention in the field of optoelectronics,due to their unique ferroelectric photovoltaic effect.Recently,substantial efforts have been devoted to the development of fe...Ferroelectric semiconductors have sparked growing attention in the field of optoelectronics,due to their unique ferroelectric photovoltaic effect.Recently,substantial efforts have been devoted to the development of ferroelectric semiconductors,including inorganic oxides,organic-inorganic hybrids,and metal-free perovskites.Nevertheless,reports of ferroelectric semiconductors with a bandgap of less than 2 eV have been scarce.Here,in combination with the incorporation of triiodide(I_(3)−)and the introduction of chiral cations,we successfully constructed a pair of enantiomeric organic-inorganic hybrid ferroelectric semiconductors,(S-1,2-DAP·I)_(4)·I_(3)·BiI_(6)and(R-1,2-DAP·I)_(4)·I_(3)·BiI_(6)(R/S-1,2-DAP=(R/S)-(–)-1,2-diaminopropane),which possess high-temperature multiaxial ferroelectric phase transition with an Aizu notation of 422F2(s)at 405 K,a narrow bandgap of 1.56 eV comparable to that of CH3NH3PbI_(3)(∼1.5 eV),and an impressive piezoelectric response(piezoelectric coefficient,d22 of 35 pC/N)on par with PVDF(polyvinylidene fluoride,30 pC/N).With intriguing attributes,(S-1,2-DAP·I)_(4)·I_(3)·BiI_(6)and(R-1,2-DAP·I)_(4)·I_(3)·BiI_(6)exhibit great potential for application of self-power polarized-light detection and piezoelectric sensors.展开更多
The dielectric response of complex perovskite relaxor ferrolectrics Pb(Mg1/3Nb2/3) O3 with respect to temperature and frequency was carefully measured. Using a normalized method of the 'universal' many-body t...The dielectric response of complex perovskite relaxor ferrolectrics Pb(Mg1/3Nb2/3) O3 with respect to temperature and frequency was carefully measured. Using a normalized method of the 'universal' many-body theory, the relaxation process was analyzed around the temperature of dielectric absorption maximum. There is no structural phase transition near this temperature and the behavior is closely like that of a polar dipole medium. The functional relationship about frequency and temperature of dielectric pormittivity maximum was also fitted to discuss the dynamic behavior of polar microregion. It is confirmed that a new power exponential Arrhenius relation is better to characterize the relaxation behavior than the Vogel-Fulcher and Debye relations. Based on the polarization theory of polar dipoles, we analyzed the relaxation mechanism of ferroelectric microdomains of relaxor ferroelectrics, and get an ideal distribution function of relaxation time. Consequently, a simulated dielectric response dependence on temperature and frequencies can be expressed, which is well coincided with experiment results.展开更多
The fracture behavior of ferroelectrics has been intensively studied in recent decades, though currently a widely accepted fracture mechanism is still lacking. In this work, enlightened by previous experimental observ...The fracture behavior of ferroelectrics has been intensively studied in recent decades, though currently a widely accepted fracture mechanism is still lacking. In this work, enlightened by previous experimental observations that crack propagation in ferroelectrics is always accompanied by domain switching, we propose a micromechanical model in which both crack propagation and domain switching are controlled by energy-based criteria. Both electric energy and mechanical energy can induce domain switching, while only mechanical energy can drive crack propagation. Furthermore, constrained domain switching is considered in this model, leading to the gradient domain switching zone near the crack tip. Analysis results show that stress-induced ferroelastic switching always has a toughening effect as the mechanical energy release rate serves as the driving force for both fracture and domain switching. In comparison, the electric-field-induced switching may have either a toughening or detoughening effect. The proposed model can qualitatively agree with the existing experimental results.展开更多
The Ginzburg-Landau theory on ferroelectrics with random field induced by dipole defects is studied by using Monte Carlo simulation, in order to investigate the dipole configuration and the dielectric relaxation of re...The Ginzburg-Landau theory on ferroelectrics with random field induced by dipole defects is studied by using Monte Carlo simulation, in order to investigate the dipole configuration and the dielectric relaxation of relaxor ferro-electrics. With the increase of random field, the dipole configuration evolves from the long-range ferroelectric order into the coexistence of short-range dipole-clusters and less polarized matrix. The dipole-cluster phase above the transition temperature and superparaelectric fluctuations far below this temperature are identified for the relaxor ferroelectrics. We investigate the frequency dispersion and the time-domain spectrum of the dielectric relaxation, demonstrating the Vogel-Fulcher relationship and the multi-peaked time-domain distribution of the dielectric relaxation.展开更多
SrBi4Ti4O15 powder was synthesized by conventional solid state synthesis （ CS ） and molten salt synthesis （ MSS ） . MSS method can synthesize plate-like SrBi4Ti4O15 at lower temperature （900℃） than CS method. P...SrBi4Ti4O15 powder was synthesized by conventional solid state synthesis （ CS ） and molten salt synthesis （ MSS ） . MSS method can synthesize plate-like SrBi4Ti4O15 at lower temperature （900℃） than CS method. Plate-like form becomes more distinct when the synthesis temperature increases. This would help cause the grain orientation of the ceramics after sintering. The sintered samples of MSS had grain orientation at （0,0, 10） plane. The degree of （0,0,10） grain orientation F was 62.1% . Hot pressing made （0,0,10） grain orientation more distinct （ F = 85.7% ）. The microstructures of the sintered samples were detected by SEM. Due to the grain orientation the density of samples fabricated by MSS was lower than that of prepared by CS.展开更多
Ferroelectrics are a type of material with a polar structure and their polarization direction can be inverted reversibly by applying an electric field.They have attracted tremendous attention for their extensive appli...Ferroelectrics are a type of material with a polar structure and their polarization direction can be inverted reversibly by applying an electric field.They have attracted tremendous attention for their extensive applications in non-volatile memory,sensors and neuromorphic computing.However,conventional ferroelectric materials face insulating and interfacial issues in the commercialization process.In contrast,two-dimensional(2D)ferroelectric materials usually have excellent semiconductor performance,clean van der Waals interfaces and robust ferroelectric order in atom-thick layers,and hold greater promise for constructing multifunctional ferroelectric optoelectronic devices and nondestructive ultra-high-density memory.Recently,2D ferroelectrics have obtained impressive breakthroughs,showing overwhelming superiority.Herein,firstly,the progress of experimental research on 2D ferroelectric materials is reviewed.Then,the preparation of 2D ferroelectric devices and their applications are discussed.Finally,the future development trend of 2D ferroelectrics is looked at.展开更多
The domains are of fundamental interest for engineering a ferroelectric material. The domain wall and its width control the ferroelectric behavior to a great extent. The stability of polarization in the context of Lan...The domains are of fundamental interest for engineering a ferroelectric material. The domain wall and its width control the ferroelectric behavior to a great extent. The stability of polarization in the context of Landau-Ginzburg free energy functional has been worked out in a previous work by a perturbation approach, where two limits of domain wall width were estimated within the stability zone and they were also found to correspond well with the data on lithium niobate and lithium tantalate. In the present work, it is shown that this model is valid for a wide range of ferroelectric materials and also for a given ferroelectric, such as lithium niobate with different levels of impurities, which are known to affect the domain wall width.展开更多
Ultrafast charge/discharge process and ultrahigh power density enable dielectrics essential components in modern electrical and electronic devices, especially in pulse power systems. However, in recent years, the ener...Ultrafast charge/discharge process and ultrahigh power density enable dielectrics essential components in modern electrical and electronic devices, especially in pulse power systems. However, in recent years, the energy storage performances of present dielectrics are increasingly unable to satisfy the growing demand for miniaturization and integration, which stimulates further researches on dielectrics with higher energy density and efficiency.Among various inorganic dielectrics, perovskite relaxor ferroelectrics are recognized as promising candidates for energy storage applications, with high permittivity and relatively high efficiency. Here, we focus on recent progress and achievements on optimizing perovskite relaxor ferroelectrics toward better energy storage capability through hierarchical design. The principles and key parameters of dielectric energy storage, together with the definition of majority types of dielectrics, are introduced at first. Strategies within various scales include domain, grain size, orientation, and composite engineering are summarized. The existing challenges are presented and future prospects are proposed in the end, with the background of both academic explorations and industrial applications.展开更多
The duality between electric and magnetic dipoles inspires recent comparisons between ferronics and magnonics.Here we predict surface polarization waves or“ferrons”in ferroelectric insulators,taking the long-range d...The duality between electric and magnetic dipoles inspires recent comparisons between ferronics and magnonics.Here we predict surface polarization waves or“ferrons”in ferroelectric insulators,taking the long-range dipolar interaction into account.We predict properties that are strikingly different from the magnetic counterpart,i.e.the surface Damon-Eshbach magnons in ferromagnets.The dipolar interaction pushes the ferron branch with locked circular polarization and momentum to the ionic plasma frequency.The low-frequency modes are on the other hand in-plane polarized normal to their wave vectors.The strong anisotropy of the lower branch renders directional emissions of electric polarization and chiral near fields when activated by a focused laser beam,allowing optical routing in ferroelectric devices.展开更多
This paper proposes a scheme based on the Potts and Ising models for simulating polarization switching of polycrystalline ferroelectrics using the Monte Carlo method. The polycrystalline texture with different average...This paper proposes a scheme based on the Potts and Ising models for simulating polarization switching of polycrystalline ferroelectrics using the Monte Carlo method. The polycrystalline texture with different average grain size is produced from the Potts model. Then Ising model is implemented in the polycrystalline texture to produce the domain pattern and hysteresis loop. The domain patterns and hysteresis loops have been obtained for polycrystalline texture with different average grain size. From the results of domain pattern evolution process under an applied electric field using this scheme, an extended domain, which covers more than one grain with polarization aligned roughly in the same direction, has been observed during the polarization reversal. This scheme can well reproduce the basic properties of polycrystalline ferroelectrics and is a valuable tool for exploring the physical properties of polycrystalline ferroelectrics.展开更多
Dielectric capacitors are independent in advanced electronics and pulse power systems as an energy storage and conversion medium.However,achieving high energy density at a low electric field remains challenging for di...Dielectric capacitors are independent in advanced electronics and pulse power systems as an energy storage and conversion medium.However,achieving high energy density at a low electric field remains challenging for dielectric materials to improve the safety of integrated electronic devices.In this work,the strategy of defect engineering-induced phase competition is proposed to improve the polarization behavior and strengthen dielectric temperature stability of(Bi,Na)TiO_(3)(BNT)-based relaxor ferroelectric,i.e.,Na_(0.325)Sr_(0.245)Ba_(0.105-1.5x)□0.5xBi_(0.325tx)TiO_(3)(NSB_(0.105-1.5x)□0.5xB_(0.325tx)T)ceramics by changing the ratio of Bi^(3+)/Ba^(2+).A high recoverable energy density(Wrec=3.6 J/cm^(3))is achieved at a relatively low electric field of 160 kV/cm for x=0.06 composition together with a high dielectric constant of 3142%±15%in a wide temperature range of 30-386℃,which exceeds other lead-free dielectric ceramics at the same electric field.The results demonstrate that NSB_(0.015)□0.03B_(0.385)T ceramics are desirable for advanced pulsed power capacitors and will push the development of defect-tuned functionality of dielectric ceramics for energy storage applications.展开更多
基金supported by generous grants from the Natural Science Foundation of Zhejiang Province(LR24E030003)Zhejiang Province Qianjiang Talent Program(ZJ-QJRC-2020-32).
文摘Elastic electronics are increasingly prevalent in information storage,smart sensing and health monitoring due to their softness,stretchability and portability.Wearable electronic devices should possess elasticity and stretchability that align with biological tissues.Specifically,their materials should be capable of elastic strain up to 50–80%,while the devices themselves must maintain electric stability under strains that accommodate body movements[1].
基金support from the Natural Science Fund for Colleges and Universities in Jiangsu Province(24KJB430029)the Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(NY224032,NY225006).
文摘Ferroelectrics(FEs)have shown great potential in sensors,actuators,and electrocaloric cooling due to their direct cross-couplings between electric polarization and mechanical,thermal,and dielectric properties[1−3]Compared with oxide FEs,polymer FEs possess good flexible and shape adaptability,making them promising candidates for flexible electronics and biocompatible devices[4].
基金financially supported by the National Natural Science Foundation of China(No.52302229)the State Key Laboratory of Photovoltaic Science and Technology of China(No.202401030301)the Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University(No.KJS2425)。
文摘Perovskite optoelectronic devices,capitalizing on the exceptional light-matter interaction and semiconductor properties of perovskite materials,have emerged as transformative platforms for energy conversion,information storage,and photonic technologies.While material innovations and device engineering breakthroughs have propelled remarkable advancements,persistent challenges in operational stability,scalable manufacturing,and batch reproducibility continue to hinder commercial implementation.Recently,molecular ferroelectrics(MOFEs),as a class of materials characterized by polar crystal structures and switchable spontaneous polarization(P_(s)),offer novel pathways to regulate high-efficiency and stable perovskite optoelectronic devices.Here,we systematically review the application of MOFEs into diverse perovskite optoelectronic systems,emphasizing the synergistic effect between P_(s)and optoelectronic properties.We analyze MOFEs-based photodetectors spanning self-powered,X-ray,and polarized-light detectors,detailing how P_(s)and synergistic physical effects optimize device performance.For photovoltaic applications,we elucidate polarizationdriven performance enhancement mechanisms in perovskite solar cells(PSCs),including built-in field amplification,defect passivation,and stability improvement.Furthermore,we envisage the emerging applications of MOFEs in optoelectronic fields such as non-volatile memory,neuromorphic computing,and optical communication.Overall,this review furnishes valuable insights into optoelectronics and future energy.
基金financially supported by the National Natural Science Foundation of China(Nos.22375182,92056112 and 21991141).
文摘The performance optimization of materials is an eternal theme and challenge in scientific research,which is reflected in ferroelectric filed to two hot topics of enhancing Curie temperature(TC)and functional versatility.The former one vitally determines ferroelectric operational temperature range while the latter would open up new application possibilities.Effective chemical modification or doping strategies on A-site and X-site components have been successfully developed in hybrid organic-inorganic perovskite(HOIP)ferroelectrics,however,the important role of adjusting B-site ions has long been overlooked.Here,we have implemented regulation on the ion radius of the B-site component to successfully obtain two new HOIP ferroelectrics(3-pyrrolinium)BBr_(3)(B=Mn and Ni).Compared to parent(3-pyrrolinium)CdBr_(3),the TC(△T=99 K)was significantly optimized by replacing the Cd^(2+)with smaller Mn^(2+)or Ni^(2+)ions.More strikingly,the introduction of Mn^(2+)and Ni^(2+)ions with octahedral coordination bring out intriguing red emission and magnetism respectively,making the multifunctional integration in a single material for multiple uses.This work provides a feasible strategy for performance optimizing of HOIP ferroelectrics,and would shed light for constructing multifunctional ferroelectrics.
基金supported by the National Natural Science Foundation of China(Nos.21865015,22071094 and 22075123)the Department of Science and Technology in Jiangxi Province(No.20213BCJ22055)。
文摘Molecular ferroelectrics have attracted much attention because of their excellent piezoelectricity,mechanical workability,and second harmonic effect.Here,we successfully prepared two molecular ferroelectrics[1,5-3.2.2-Hdabcn]X(X=ClO_(4)^(-),1;ReO_(4)^(-),2)by reactions of a quasi-spherical amine 1,5-diazabicycle[3.2.2]nonane(1.5-3.2.2-dabcn)with HX aqueous solution.Compounds 1 and 2 undergo hightemperature phase transitions at 381 K(1)and 396 K(2).Before and after the phase transition,they crystallize in the polar point group mm2,and the centrosymmetric point groups mmm and 4/mmm,respectively.According to Aizu rules,these two compounds experience mmm Fmm2 and 4/mmm Fmm2 type ferroelectric phase transitions,respectively.The ferroelectricity of both compounds is well expressed in their polycrystalline film at room temperature with low coercive voltages of 13 V for 1 and 25 V for 2.Using piezoelectric force microscopy(PFM),the 180°anti-parallel ferroelectric domains and the reversible polarization switching can be clearly observed in 1 and 2.This high-temperature molecular ferroelectric material has great application potential in flexible materials,biomechanics,intelligent wearables and other fields.
基金supported by the National Natural Science Foundation of China(Grant Nos.21825102,22235002,52172181,and 22105017)Key R&D Plan of the Ministry of Science and Technology of China(Grant No.2022YFB3204000)。
文摘Advanced lead-free energy storage ceramics play an indispensable role in next-generation pulse power capacitors market.Here,an ultrahigh energy storage density of~13.8 J cm^(-3)and a large efficiency of~82.4%are achieved in high-entropy lead-free relaxor ferroelectrics by increasing configuration entropy,named high-entropy strategy,realizing nearly ten times growth of energy storage density compared with low-entropy material.Evolution of energy storage performance and domain structure with increasing configuration entropy is systematically revealed for the first time.The achievement of excellent energy storage properties should be attributed to the enhanced random field,decreased nanodomain size,strong multiple local distortions,and improved breakdown field.Furthermore,the excellent frequency and fatigue stability as well as charge/discharge properties with superior thermal stability are also realized.The significantly enhanced comprehensive energy storage performance by increasing configuration entropy demonstrates that high entropy is an effective but convenient strategy to design new high-performance dielectrics,promoting the development of advanced capacitors.
基金Project supported by the Major State Basic Research Development Program of China(Grant Nos.2013CB922302 and 2016YFA0203900)the Natural Science Foundation of China(Grant Nos.11322441,614404147,61574152,and 61674157)the Key Research Project of Frontier Science of Chinese Academy of Sciences(Grant Nos.QYZDB-SSW-JSC016 and QYZDB-SSW-JSC031)
文摘Two-dimensional （2D） materials, such as graphene and MoS2 related transition metal dichalcogenides （TMDC）, have attracted much attention for their potential applications. Ferroelectrics, one of the special and traditional dielectric materials, possess a spontaneous electric polarization that can be reversed by the application of an external electric field. In recent years, a new type of device, combining 2D materials with ferroelectrics, has been fabricated. Many novel devices have been fabricated, such as low power consumption memory devices, highly sensitive photo-transistors, etc. using this technique of hybrid systems incorporating ferroelectrics and 2D materials. This paper reviews two types of devices based on field effect transistor （FET） structures with ferroelectric gate dielectric construction （termed FeFET）. One type of device is for logic applications, such as a graphene and TMDC FeFET for fabricating memory units. Another device is for optoelectric applications, such as high performance phototransistors using a graphene p-n junction. Finally, we discuss the prospects for future applications of 2D material FeFET.
基金Project supported by the National Natural Science Foundation of China(Grant No.11704242)the Natural Science Foundation of Shanghai,China(Grant No.17ZR1447200)
文摘The electrocaloric effect of the model ferroelectric BaTiO3was investigated using phenomenological theory. The results indicate that the applied electric field strength is a key factor for the induced electrocaloric response and there are two distinguishing electrocaloric responses. When a moderate electric field is applied, the electrocaloric temperature variation is small but the electrocaloric strength is high. In contrast, the electrocaloric temperature variation is large but electrocaloric strength is low when a very high electric field is applied. These results are consistent with the experimental observations on BaTiO3based bulk and thin film ferroelectric materials.
基金This work was supported financially by the National Key Research and Development Program of China(No.2017YFA0204800)National Natural Science Foundation of China(Nos.22175079 and 21875093)+3 种基金Natural Science Foundation of Jiangxi Province(Nos.20204BCJ22015 and 20202ACBL203001)Jiangxi Provincial Department of Education Science and Technology Research Project(No.GJJ210812)Jiangxi Provincial Natural Science Foundation of China(No.20212BAB214021)Science and Technology Project of Jiangxi Provincial Department of Education(No.GJJ200836).
文摘Ferroelectric semiconductors have sparked growing attention in the field of optoelectronics,due to their unique ferroelectric photovoltaic effect.Recently,substantial efforts have been devoted to the development of ferroelectric semiconductors,including inorganic oxides,organic-inorganic hybrids,and metal-free perovskites.Nevertheless,reports of ferroelectric semiconductors with a bandgap of less than 2 eV have been scarce.Here,in combination with the incorporation of triiodide(I_(3)−)and the introduction of chiral cations,we successfully constructed a pair of enantiomeric organic-inorganic hybrid ferroelectric semiconductors,(S-1,2-DAP·I)_(4)·I_(3)·BiI_(6)and(R-1,2-DAP·I)_(4)·I_(3)·BiI_(6)(R/S-1,2-DAP=(R/S)-(–)-1,2-diaminopropane),which possess high-temperature multiaxial ferroelectric phase transition with an Aizu notation of 422F2(s)at 405 K,a narrow bandgap of 1.56 eV comparable to that of CH3NH3PbI_(3)(∼1.5 eV),and an impressive piezoelectric response(piezoelectric coefficient,d22 of 35 pC/N)on par with PVDF(polyvinylidene fluoride,30 pC/N).With intriguing attributes,(S-1,2-DAP·I)_(4)·I_(3)·BiI_(6)and(R-1,2-DAP·I)_(4)·I_(3)·BiI_(6)exhibit great potential for application of self-power polarized-light detection and piezoelectric sensors.
文摘The dielectric response of complex perovskite relaxor ferrolectrics Pb(Mg1/3Nb2/3) O3 with respect to temperature and frequency was carefully measured. Using a normalized method of the 'universal' many-body theory, the relaxation process was analyzed around the temperature of dielectric absorption maximum. There is no structural phase transition near this temperature and the behavior is closely like that of a polar dipole medium. The functional relationship about frequency and temperature of dielectric pormittivity maximum was also fitted to discuss the dynamic behavior of polar microregion. It is confirmed that a new power exponential Arrhenius relation is better to characterize the relaxation behavior than the Vogel-Fulcher and Debye relations. Based on the polarization theory of polar dipoles, we analyzed the relaxation mechanism of ferroelectric microdomains of relaxor ferroelectrics, and get an ideal distribution function of relaxation time. Consequently, a simulated dielectric response dependence on temperature and frequencies can be expressed, which is well coincided with experiment results.
基金supported by the National Natural Science Foundation of China (Grants 11422216, 11521202)
文摘The fracture behavior of ferroelectrics has been intensively studied in recent decades, though currently a widely accepted fracture mechanism is still lacking. In this work, enlightened by previous experimental observations that crack propagation in ferroelectrics is always accompanied by domain switching, we propose a micromechanical model in which both crack propagation and domain switching are controlled by energy-based criteria. Both electric energy and mechanical energy can induce domain switching, while only mechanical energy can drive crack propagation. Furthermore, constrained domain switching is considered in this model, leading to the gradient domain switching zone near the crack tip. Analysis results show that stress-induced ferroelastic switching always has a toughening effect as the mechanical energy release rate serves as the driving force for both fracture and domain switching. In comparison, the electric-field-induced switching may have either a toughening or detoughening effect. The proposed model can qualitatively agree with the existing experimental results.
基金supported by the National Natural Science Foundation of China (Grant Nos.50832002 and 10874035)the National Basic Research Program of China (Grant No.2009CB623303)
文摘The Ginzburg-Landau theory on ferroelectrics with random field induced by dipole defects is studied by using Monte Carlo simulation, in order to investigate the dipole configuration and the dielectric relaxation of relaxor ferro-electrics. With the increase of random field, the dipole configuration evolves from the long-range ferroelectric order into the coexistence of short-range dipole-clusters and less polarized matrix. The dipole-cluster phase above the transition temperature and superparaelectric fluctuations far below this temperature are identified for the relaxor ferroelectrics. We investigate the frequency dispersion and the time-domain spectrum of the dielectric relaxation, demonstrating the Vogel-Fulcher relationship and the multi-peaked time-domain distribution of the dielectric relaxation.
文摘SrBi4Ti4O15 powder was synthesized by conventional solid state synthesis （ CS ） and molten salt synthesis （ MSS ） . MSS method can synthesize plate-like SrBi4Ti4O15 at lower temperature （900℃） than CS method. Plate-like form becomes more distinct when the synthesis temperature increases. This would help cause the grain orientation of the ceramics after sintering. The sintered samples of MSS had grain orientation at （0,0, 10） plane. The degree of （0,0,10） grain orientation F was 62.1% . Hot pressing made （0,0,10） grain orientation more distinct （ F = 85.7% ）. The microstructures of the sintered samples were detected by SEM. Due to the grain orientation the density of samples fabricated by MSS was lower than that of prepared by CS.
基金Project supported by the National Key Research and Development Program of China (Grant No.2022YFB3505301)the National Natural Science Foundation of China (Grant Nos.12241403 and12174237)the Graduate Education Innovation Project in Shanxi Province (Grant No.2021Y484)。
文摘Ferroelectrics are a type of material with a polar structure and their polarization direction can be inverted reversibly by applying an electric field.They have attracted tremendous attention for their extensive applications in non-volatile memory,sensors and neuromorphic computing.However,conventional ferroelectric materials face insulating and interfacial issues in the commercialization process.In contrast,two-dimensional(2D)ferroelectric materials usually have excellent semiconductor performance,clean van der Waals interfaces and robust ferroelectric order in atom-thick layers,and hold greater promise for constructing multifunctional ferroelectric optoelectronic devices and nondestructive ultra-high-density memory.Recently,2D ferroelectrics have obtained impressive breakthroughs,showing overwhelming superiority.Herein,firstly,the progress of experimental research on 2D ferroelectric materials is reviewed.Then,the preparation of 2D ferroelectric devices and their applications are discussed.Finally,the future development trend of 2D ferroelectrics is looked at.
文摘The domains are of fundamental interest for engineering a ferroelectric material. The domain wall and its width control the ferroelectric behavior to a great extent. The stability of polarization in the context of Landau-Ginzburg free energy functional has been worked out in a previous work by a perturbation approach, where two limits of domain wall width were estimated within the stability zone and they were also found to correspond well with the data on lithium niobate and lithium tantalate. In the present work, it is shown that this model is valid for a wide range of ferroelectric materials and also for a given ferroelectric, such as lithium niobate with different levels of impurities, which are known to affect the domain wall width.
基金financially supported by the National Natural Science Foundation of China (No.51788104)。
文摘Ultrafast charge/discharge process and ultrahigh power density enable dielectrics essential components in modern electrical and electronic devices, especially in pulse power systems. However, in recent years, the energy storage performances of present dielectrics are increasingly unable to satisfy the growing demand for miniaturization and integration, which stimulates further researches on dielectrics with higher energy density and efficiency.Among various inorganic dielectrics, perovskite relaxor ferroelectrics are recognized as promising candidates for energy storage applications, with high permittivity and relatively high efficiency. Here, we focus on recent progress and achievements on optimizing perovskite relaxor ferroelectrics toward better energy storage capability through hierarchical design. The principles and key parameters of dielectric energy storage, together with the definition of majority types of dielectrics, are introduced at first. Strategies within various scales include domain, grain size, orientation, and composite engineering are summarized. The existing challenges are presented and future prospects are proposed in the end, with the background of both academic explorations and industrial applications.
基金financially supported by the National Natural Science Foundation of China(Grant No.0214012051)the startup grant of Huazhong University of Science and Technology(Grants Nos.3004012185,3004012198)+5 种基金the financial support by JSPS KAKENHI(Grant Nos.19H00645,22H04965)financially supported in Brazil by Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)Coordenac ao de Aperfeicoamento de Pessoal de Nível Superior(CAPES)Financiadora de Estudos e Projetos(FINEP)Fundac ao de AmparoáCiencia e Tecnologia do Estado de Pernambuco(FACEPE)in Chile by Fondo Nacional de Desarrollo Científico y Tecnológico(FONDECYT)(Grant No.1210641)。
文摘The duality between electric and magnetic dipoles inspires recent comparisons between ferronics and magnonics.Here we predict surface polarization waves or“ferrons”in ferroelectric insulators,taking the long-range dipolar interaction into account.We predict properties that are strikingly different from the magnetic counterpart,i.e.the surface Damon-Eshbach magnons in ferromagnets.The dipolar interaction pushes the ferron branch with locked circular polarization and momentum to the ionic plasma frequency.The low-frequency modes are on the other hand in-plane polarized normal to their wave vectors.The strong anisotropy of the lower branch renders directional emissions of electric polarization and chiral near fields when activated by a focused laser beam,allowing optical routing in ferroelectric devices.
基金Project supported by National Natural Science Foundation of China (Grant No 10474057)
文摘This paper proposes a scheme based on the Potts and Ising models for simulating polarization switching of polycrystalline ferroelectrics using the Monte Carlo method. The polycrystalline texture with different average grain size is produced from the Potts model. Then Ising model is implemented in the polycrystalline texture to produce the domain pattern and hysteresis loop. The domain patterns and hysteresis loops have been obtained for polycrystalline texture with different average grain size. From the results of domain pattern evolution process under an applied electric field using this scheme, an extended domain, which covers more than one grain with polarization aligned roughly in the same direction, has been observed during the polarization reversal. This scheme can well reproduce the basic properties of polycrystalline ferroelectrics and is a valuable tool for exploring the physical properties of polycrystalline ferroelectrics.
基金supported by National Natural Science Foundation of China(52267002)Natural Science Foundation of Jiangxi Province(20212ACB204010)Science&Technology Research Project of Jiangxi Provincial Education Department(GJJ211301).
文摘Dielectric capacitors are independent in advanced electronics and pulse power systems as an energy storage and conversion medium.However,achieving high energy density at a low electric field remains challenging for dielectric materials to improve the safety of integrated electronic devices.In this work,the strategy of defect engineering-induced phase competition is proposed to improve the polarization behavior and strengthen dielectric temperature stability of(Bi,Na)TiO_(3)(BNT)-based relaxor ferroelectric,i.e.,Na_(0.325)Sr_(0.245)Ba_(0.105-1.5x)□0.5xBi_(0.325tx)TiO_(3)(NSB_(0.105-1.5x)□0.5xB_(0.325tx)T)ceramics by changing the ratio of Bi^(3+)/Ba^(2+).A high recoverable energy density(Wrec=3.6 J/cm^(3))is achieved at a relatively low electric field of 160 kV/cm for x=0.06 composition together with a high dielectric constant of 3142%±15%in a wide temperature range of 30-386℃,which exceeds other lead-free dielectric ceramics at the same electric field.The results demonstrate that NSB_(0.015)□0.03B_(0.385)T ceramics are desirable for advanced pulsed power capacitors and will push the development of defect-tuned functionality of dielectric ceramics for energy storage applications.
