Based on Peltier effect,Bi_(2)Te_(3)-based alloy is widely used in commercial solid-state refrigeration at room temperature.The mainstream strategies for enhancing room-temperature thermoelectric performance in Bi_(2)...Based on Peltier effect,Bi_(2)Te_(3)-based alloy is widely used in commercial solid-state refrigeration at room temperature.The mainstream strategies for enhancing room-temperature thermoelectric performance in Bi_(2)Te_(3)focus on band and microstructure engineering.However,a clear understanding of the modulation of band structure and scattering through such engineering remains still challenging,because the minority carriers compensate partially the overall transport properties for the narrow-gap Bi_(2)Te_(3)at room temperature(known as the bipolar effect).The purpose of this work is to model the transport properties near and far away from the bipolar effect region for Bi_(2)Te_(3)-based thermoelectric material by a two-band model taking contributions of both majority and minority carriers into account.This is endowed by shifting the Fermi level from the conduction band to the valence band during the modeling.A large amount of data of Bi_(2)Te_(3)-based materials is collected from various studies for the comparison between experimental and predicted properties.The fundamental parameters,such as the density of states effective masses and deformation potential coefficients,of Bi_(2)Te_(3)-based materials are quantified.The analysis can help find out the impact factors(e.g.the mobility ratio between conduction and valence bands)for the improvement of thermoelectric properties for Bi_(2)Te_(3)-based alloys.This work provides a convenient tool for analyzing and predicting the transport performance even in the presence of bipolar effect,which can facilitate the development of the narrow-gap thermoelectric semiconductors.展开更多
Tetradymite-structured chalcogenides,such as Bi_(2)Te_(3) and Sb_(2)Te_(3),are quasi-two-dimensional(2D)layered compounds,which are significant thermoelectric materials applied near room temperature.The intercalation ...Tetradymite-structured chalcogenides,such as Bi_(2)Te_(3) and Sb_(2)Te_(3),are quasi-two-dimensional(2D)layered compounds,which are significant thermoelectric materials applied near room temperature.The intercalation of guest species in van der Waals(vdW)gap implemented for tunning properties has attracted much attention in recent years.We attempt to insert Ga atoms in the vdW gap between the Te layers in p-type Bi_(0.3)Sb_(1.7)Te_(3)(BST)for further improving thermoelectrics.The vdW-related defects(including extrinsic interstitial and intrinsic defects)induced by Ga intercalation can not only modulate the carrier concentration but also enhance the texture,thereby yielding excellent electrical properties,which are reflected in the power factor PF~4.43 mW·m^(-1)·K^(-2).Furthermore,the intercalation of Ga produces multi-scale lattice imperfections such as point defects,Te precipitations,and nanopores,realizing the low lattice thermal conductivity in BST-Ga samples.Ultimately,a peak zT~1.1 at 373 K is achieved in the BST-1%Ga sample and greatly improved by~22%compared to the pristine BST.The weak bonding of vdW interlayer interaction can boost the synergistic effect for advancing BST-based or other layered thermoelectrics.展开更多
AgCrSe2-based compounds have attracted much attention as an environmentally friendly thermoelectric material in recent years due to the intriguing liquid-like properties.However,the ultra-low carrier concentration and...AgCrSe2-based compounds have attracted much attention as an environmentally friendly thermoelectric material in recent years due to the intriguing liquid-like properties.However,the ultra-low carrier concentration and the high Ag_(Cr)deep-level defects limit the overall thermoelectric performance.Here,we successfully introduced Pb into Ag-deficient Ag_(0.97)CrSe_(2) alloys to tune the carrier concentration across a broad temperature range.The Pb^(2+) as an acceptor dopant preferentially occupies Cr sites,boosting the hole carrier concentration to 1.77×10^(19) cm^(-3) at room temperature.Furthermore,the Pb strongly inhibits the creation of intrinsic Ag_(Cr) defects,weakens the increased thermal excited ionization with the increasing temperature and slowed the rising trend of the carrier concentration.The designed carrier concentration matches the theoretically predicted optimized one over the entire temperature range,leading to a remarkable enhancement in power factor,especially the maximum power factor of ~500 μW·m^(-1)·K^(-2) at 750 K is superior to most previous results.Additionally,the abundant point defects promote phonon scattering,thus reducing the lattice thermal conductivity.As a result,the maximum figure of merit zT(~0.51 at 750 K) is achieved in Ag_(0.97)Cr_(0.995)Pb_(0.005)Se_(2).This work confirms the feasibility of manipulating deep-level defects to achieve temperature-dependent optimal carrier concentration and provides a valuable guidance for other thermoelectric materials.展开更多
Nonisovalent(GaN)_(1-x)(ZnO)_(x)alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap.Unfortunately,the lack of two-dimensional(2D)configurations as well as ...Nonisovalent(GaN)_(1-x)(ZnO)_(x)alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap.Unfortunately,the lack of two-dimensional(2D)configurations as well as complete stoichiometries hinders to further explore the thermal transport,thermoelectrics,and adsorption/permeation.We identify that multilayer(GaN)_(1-x)(ZnO)_(x)stabilize as wurtzite-like Pm-(GaN)_(3)(ZnO)_(1),Pmc2_(1)-(Ga N)_(1)(ZnO)_(1),P3m1-(GaN)_(1)(ZnO)_(2),and haeckelite C2/m-(GaN)_(1)(ZnO)_(3)via structural searches.P3m1-(GaN)_(1)(ZnO)_(2)shares the excellent thermoelectrics with the figure of merit ZT as high as 3.08 at 900 K for the p-type doping due to the ultralow lattice thermal conductivity,which mainly arises from the strong anharmonicity by the interlayer asymmetrical charge distributions.The p–d coupling is prohibited from the group theory in C2/m-(Ga N)_(1)(ZnO)_(3),which thereby results in the anomalous band structure versus Zn O composition.To unveil the adsorption/permeation of H^(+),Na^(+),and OH^(-)ions in AA-stacking configurations,the potential wells and barriers are explored from the Coulomb interaction and the ionic size.Our work is helpful in experimental fabrication of novel optoelectronic and thermoelectric devices by 2D(GaN)_(1-x)(ZnO)_(x)alloys.展开更多
The density junction theory and discrete variation method ( DFT - DVM) was used to study correlation between composition, structure, chemical bond, and property of thermoelectrics of Bi-Sb-Te series. 8 models of Bi20-...The density junction theory and discrete variation method ( DFT - DVM) was used to study correlation between composition, structure, chemical bond, and property of thermoelectrics of Bi-Sb-Te series. 8 models of Bi20-xSbxTe32(x = 0,2,6,8,12,14,18 and 20) were calculated. The results show that there is less difference in the ionic bonds between Te( I)-Bi(Sb) and Te(Ⅱ)-Bi(Sb) , but the covalent bond of Te(Ⅰ)-Bi( Sb ) is stronger than that of Te(Ⅱ)-Bi( Sb ) . The interaction between Te(Ⅰ) and Te(Ⅰ) in different layers is the weakest and the interaction should be Van Der Wools power. The charge of Sb is lower than that of Bi, and the ionic bond of Te-Sb is weaker than that of Te-Bi. The covalent bond of Te-Sb is also weaker than that of Te-Bi. Therefore, the thermoelectric property may be imfiroved by adjusting the electrical conductivity and thermal conductivity through changing the composition in the compounds of Bi-Sb-Te. The calculated results are consistent with the experiments.展开更多
Ionic thermoelectricity(i-TE),as a new energy conversion and storage technology,has been widely discussed by the academic community.As one of the representatives of low-grade thermal energy recovery,i-TE has made rema...Ionic thermoelectricity(i-TE),as a new energy conversion and storage technology,has been widely discussed by the academic community.As one of the representatives of low-grade thermal energy recovery,i-TE has made remarkable progress and become an influential research direction in the energy field.Among them,thermoelectric ionogels have a wide range of applications in the field of energy recovery and utilization due to their excellent flexibility,stability,and thermoelectric conversion ability,providing many application possibilities for such materials.The development of highly efficient and stable ionic thermoelectric devices is largely dependent on the development of new materials and structural designs.This paper focuses on the recent strategies for improving the efficiency of thermoelectric conversion in the field of ionic thermoelectric gels,including new methods for material design,structural optimization,and innovative developments in the application of thermoelectric materials.The evaluation indicators of thermoelectric conversion efficiency are discussed,including ionic thermal voltage,ionic conductivity and power output,ductility,and self-healing properties.Additionally,various application devices based on thermoelectric materials with excellent thermoelectric conversion properties are highlighted.Further,different challenges and strategies that need to be addressed are presented in the hope of providing inspiration and guidance for the commercialization of i-TE.展开更多
Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight,compactness,noise-free operation,and precision reliability,wearable thermoelectrics show grea...Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight,compactness,noise-free operation,and precision reliability,wearable thermoelectrics show great potential for diverse applications.Among them,weavable thermoelectrics,a subclass with inherent flexibility,wearability,and operability,find utility in harnessing waste heat from irregular heat sources.Given the rapid advancements in this field,a timely review is essential to consolidate the progress and challenge.Here,we provide an overview of the state of weavable thermoelectric materials and devices in wearable smart textiles,encompassing mechanisms,materials,fabrications,device structures,and applications from recent advancements,challenges,and prospects.This review can serve as a valuable reference for researchers in the field of flexible wearable thermoelectric materials and devices and their applications.展开更多
Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].Howev...Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].However,despite widespread applications,thermoelectric technology remains constrained by material performance[2].展开更多
The crystal-structure symmetry in real space can be inherited in the reciprocal space,making high-symmetry materials the top candidates for thermoelectrics due to their potential for significant electronic band degene...The crystal-structure symmetry in real space can be inherited in the reciprocal space,making high-symmetry materials the top candidates for thermoelectrics due to their potential for significant electronic band degeneracy.A practical indicator that can quantitatively describe structural changes would help facilitate the advanced thermoelectric material design.In face-centered cubic structures,the spatial environment of the same crystallographic plane family is isotropic,such that the distances between the close-packed layers can be derived from the atomic distances within the layers.Inspired by this,the relationship between inter-and intra-layer geometric information can be used to compare crystal structures with their desired cubic symmetry.The close-packed layer spacing was found to be a practical guideline of crystal structure symmetry in IV-VI chalcogenides and I-V-VI_(2) ternary semiconductors,both of which are historically important thermoelectrics.The continuous structural evolution toward high symmetry can be described by the layer spacing when temperature or/and composition change,which is demonstrated by a series of pristine and alloyed thermoelectric materials in this work.The layerspacing-based guideline provides a quantitative pathway for manipulating crystal structures to improve the electrical and thermal properties of thermoelectric materials.展开更多
Exploring high-performance thermoelectric materials with improved mechanical properties is important for broadening the application scope and the assembly requirement of stable devices.This work presents an effective ...Exploring high-performance thermoelectric materials with improved mechanical properties is important for broadening the application scope and the assembly requirement of stable devices.This work presents an effective strategy to discover hard thermoelectric material by inserting foreign atoms in the rigid covalent framework.We demonstrate this in boron-carbon clathrate VII structure,showing a promising candidate for highly efficient thermoelectric energy conversion,especially with Y atom filled in the cage,with a peak zT of 0.73 at 1,000 K.The ab initio calculations indicate that YB_(3)C_(3) system has low lattice thermal conductivity of 4.5 W/(m·K)at 1,000 K due to the strong rattling of encaged Y atom.The strongly covalent framework provides highly degenerate band structures consisting of heavy and light electron pockets,which can maintain high carrier mobility arising from small effective mass and thus large group velocity.Consequently,high power factor can be achieved in YB_(3)C_(3) for both electron and hole doping.In addition,it exhibits well mechanical properties and a Vickers hardness of 23.7 GPa because of the strong covalent boron-carbon framework.This work provides a novel avenue for the search of high-performance thermoelectric materials with excellent mechanical properties,based on boron-carbon clathrate structure.展开更多
Recently,off-centering behavior has been discovered in a series of thermoelectric materials.This behavior indicates that the constituent atoms of the lattice displace from their coordination centers,leading to the loc...Recently,off-centering behavior has been discovered in a series of thermoelectric materials.This behavior indicates that the constituent atoms of the lattice displace from their coordination centers,leading to the locally distorted state and local symmetry breaking,while the material still retains its original crystallographic symmetry.This effect has been proved to be the root cause of ultralow thermal conductivity in off-centering materials,and is considered as an effective tool to regulate the thermal conductivity and improve the thermoelectric performance.Herein,we present a collection of recently discovered off-centering compounds,discuss their electronic origins and local coordination structures,and illuminate the underlying mechanism of the off-centering effect on phonon transport and thermal conductivity.This paper presents a comprehensive view of our current understanding to the off-centering effect,and provides a new idea for designing high performance thermoelectrics.展开更多
Following the Materials Genome Initiative project,materials research has embarked a new research paradigm centered around material repositories,significantly accelerating the discovery of novel materials,such as therm...Following the Materials Genome Initiative project,materials research has embarked a new research paradigm centered around material repositories,significantly accelerating the discovery of novel materials,such as thermoelectrics.Thermoelectric materials,capable of directly converting heat into electricity,are garnering increasing attention in applications like waste heat recovery and refrigeration.To facilitate research in this emerging paradigm,we have established the Materials Hub with Three-Dimensional Structures(MatHub-3d)repository,which serves as the foundation for high-throughput(HTP)calculations,property analysis,and the design of thermoelectric materials.In this review,we summarize recent advancements in thermoelectric materials powered by the MatHub-3d,specifically HTP calculations of transport properties and material design on key factors.For HTP calculations,we develop the electrical transport package for HTP purpose,and utilize it for materials screening.In some works,we investigate the relationship between transport properties and chemical bonds for particular types of thermoelectric compounds based on HTP results,enhancing the fundamental understanding about interested compounds.In our work associated with material design,we primarily utilize key factors beyond transport properties to further expedite materials screening and speedily identify specific materials for further theoretical/experimental analyses.Finally,we discuss the future developments of the MatHub-3d and the evolving directions of database-driven thermoelectric research.展开更多
With the development and prosperity of Internet of Things(IoT)technology,wearable electronics have brought fresh changes to our lives.The demands for low power consumption and mini-type wearable power systems for wear...With the development and prosperity of Internet of Things(IoT)technology,wearable electronics have brought fresh changes to our lives.The demands for low power consumption and mini-type wearable power systems for wearable electronics are more urgent than ever.Thermoelectric materials can efficiently convert the temperature difference between body and environment into electrical energy without the need for mechanical components,making them one of the ideal candidates for wearable power systems.In recent years,a variety of high-performance thermoelectric materials and processes for the preparation of large-scale single-fiber devices have emerged,driving the application of flexible fiber-based thermoelectric generators.By weaving thermoelectric fibers into a textile that conforms to human skin,it can achieve stable operation for long periods even when the human body is in motion.In this review,the complete process from thermoelectric materials to single-fiber/yarn devices to thermoelectric textiles is introduced comprehensively.Strategies for enhancing thermoelectric performance,processing techniques for fiber devices,and the wide applications of thermoelectric textiles are summarized.In addition,the challenges of ductile thermoelectric materials,system integration,and specifications are discussed,and the relevant developments in this field are prospected.展开更多
Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature moni...Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great challenge.Herein,a highly elastic,flame-retardant and high-temperature-resistant TE aerogel,made of poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube(PEDOT:PSS/SWCNT)composites,has been fabricated,displaying attractive compression-induced power factor enhancement.The as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range monitoring.Subsequently,a flexible TE generator is assembled,consisting of 25 aerogels connected in series,capable of delivering a maximum output power of 400μW when subjected to a temperature difference of 300 K.This demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature pipelines.Moreover,the designed self-powered wearable sensing glove can realize precise wide-range temperature detection,high-temperature warning and accurate recognition of human hand gestures.The aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning capability.Benefitting from these desirable properties,the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring,industrial overheat warning,waste heat energy recycling and even wearable healthcare.展开更多
The rapid development of the global economy and population growth are accompanied by the production of numerous waste textiles.This leads to a waste of limited resources and serious environmental pollution problems ca...The rapid development of the global economy and population growth are accompanied by the production of numerous waste textiles.This leads to a waste of limited resources and serious environmental pollution problems caused by improper disposal.The rational recycling of wasted textiles and their transformation into high-value-added emerging products,such as smart wearable devices,is fascinating.Here,we propose a novel roadmap for turning waste cotton fabrics into three-dimensional elastic fiber-based thermoelectric aerogels by a one-step lyophilization process with decoupled self-powered temperature-compression strain dual-parameter sensing properties.The thermoelectric aerogel exhibits a fast compression response time of 0.2 s,a relatively high Seebeck coefficient of 43μV·K^(-1),and an ultralow thermal conductivity of less than 0.04 W·m^(-1)·K^(-1).The cross-linking of trimethoxy(methyl)silane(MTMS)and cellulose endowed the aerogel with excellent elasticity,allowing it to be used as a compressive strain sensor for guessing games and facial expression recognition.In addition,based on the thermoelectric effect,the aerogel can perform temperature detection and differentiation in self-powered mode with the output thermal voltage as the stimulus signal.Furthermore,the wearable system,prepared by connecting the aerogel-prepared array device with a wireless transmission module,allows for temperature alerts in a mobile phone application without signal interference due to the compressive strains generated during gripping.Hence,our strategy is significant for reducing global environmental pollution and provides a revelatory path for transforming waste textiles into high-value-added smart wearable devices.展开更多
We present a method to fabricate handcrafted thermoelectric devices on standard office paper substrates.The devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(N-type semic...We present a method to fabricate handcrafted thermoelectric devices on standard office paper substrates.The devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(N-type semiconductors),deposited by simply rubbing powder of these materials against paper.The thermoelectric properties of these semiconducting films revealed maximum Seebeck coefficients of(+1.32±0.27)mV K^(-1)and(-0.82±0.15)mV K^(-1)for WS_(2)and TiS_(3),respectively.Additionally,Peltier elements were fabricated by interconnecting the P-and N-type films with graphite electrodes.A thermopower value up to 6.11 mV K^(-1)was obtained when the Peltier element were constructed with three junctions.The findings of this work show proof-of-concept devices to illustrate the potential application of semiconducting van der Waals materials in future thermoelectric power generation as well as temperature sensing for low-cost disposable electronic devices.展开更多
A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manu...A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manuscript.An erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further enhanced.The optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,respectively.The target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip QTF.An improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF.展开更多
The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the ene...The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.展开更多
Flexible thermoelectric materials play an important role in smart wearables,such as wearable power generation,self-powered sensing,and personal thermal management.However,with the rapid development of Internet of Thin...Flexible thermoelectric materials play an important role in smart wearables,such as wearable power generation,self-powered sensing,and personal thermal management.However,with the rapid development of Internet of Things(IoT)and artificial intelligence(AI),higher standards for comfort,multifunctionality,and sustainable operation of wearable electronics have been proposed,and it remains challenging to meet all the requirements of currently reported thermoelectric devices.Herein,we present a multifunctional,wearable,and wireless sensing system based on a thermoelectric knitted fabric with over 600 mm·s^(-1)air permeability and a stretchability of 120%.The device coupled with a wireless transmission system realizes self-powered monitoring of human respiration through an mobile phone application(APP).Furthermore,an integrated thermoelectric system was designed to combine photothermal conversion and passive radiative cooling,enabling the characteristics of being powered by solar-driven in-plane temperature differences and monitoring outdoor sunlight intensity through the APP.Additionally,we decoupled the complex signals of resistance and thermal voltage during deformation under solar irradiation based on the anisotropy of the knitted fabrics to enable the device to monitor and optimize the outdoor physical activity of the athlete via the APP.This novel thermoelectric fabricbased wearable and wireless sensing platform has promising applications in next-generation smart textiles.展开更多
The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric performance.However,the role of such a ferroelectric-like structural ...The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric performance.However,the role of such a ferroelectric-like structural distortion on its transport properties remains unclear.Herein,we performed a systematic study on the crystal structure and electronic band structure evolutions of Ge_(1-x)Sn_(x)Te alloys where the degree of ferroelectric distortion is continuously tuned.It is revealed that the band gap is maximized while multiple valence bands are converged at x=0.6,where the ferroelectric distortion is the least but still works.Once undistorted,the band gap is considerably reduced,and the valence bands are largely separated again.Moreover,near the ferro-to-paraelectric phase transition Curie temperature,the lattice thermal conductivity reaches its minima because of significant lattice softening enabled by ferroelectric instability.We predict a peak ZT value of 2.6 at 673 K inα-GeTe by use of proper dopants which are powerful in suppressing the excess hole concentrations but meanwhile exert little influence on the ferroelectric distortion.展开更多
基金National Natural Science Foundation of China(T2125008,92263108,92163203,52102292,52003198)Shanghai Rising-Star Program(23QA1409300)Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-07-E00096)。
文摘Based on Peltier effect,Bi_(2)Te_(3)-based alloy is widely used in commercial solid-state refrigeration at room temperature.The mainstream strategies for enhancing room-temperature thermoelectric performance in Bi_(2)Te_(3)focus on band and microstructure engineering.However,a clear understanding of the modulation of band structure and scattering through such engineering remains still challenging,because the minority carriers compensate partially the overall transport properties for the narrow-gap Bi_(2)Te_(3)at room temperature(known as the bipolar effect).The purpose of this work is to model the transport properties near and far away from the bipolar effect region for Bi_(2)Te_(3)-based thermoelectric material by a two-band model taking contributions of both majority and minority carriers into account.This is endowed by shifting the Fermi level from the conduction band to the valence band during the modeling.A large amount of data of Bi_(2)Te_(3)-based materials is collected from various studies for the comparison between experimental and predicted properties.The fundamental parameters,such as the density of states effective masses and deformation potential coefficients,of Bi_(2)Te_(3)-based materials are quantified.The analysis can help find out the impact factors(e.g.the mobility ratio between conduction and valence bands)for the improvement of thermoelectric properties for Bi_(2)Te_(3)-based alloys.This work provides a convenient tool for analyzing and predicting the transport performance even in the presence of bipolar effect,which can facilitate the development of the narrow-gap thermoelectric semiconductors.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFB3803900 and 2018YFA0702100)the Joint Funds of the National Natural Science Foundation of China and the Chinese Academy of Sciences’Large-Scale Scientific Facility(Grant No.U1932106)the Sichuan University Innovation Research Program of China(Grant No.2020SCUNL112)。
文摘Tetradymite-structured chalcogenides,such as Bi_(2)Te_(3) and Sb_(2)Te_(3),are quasi-two-dimensional(2D)layered compounds,which are significant thermoelectric materials applied near room temperature.The intercalation of guest species in van der Waals(vdW)gap implemented for tunning properties has attracted much attention in recent years.We attempt to insert Ga atoms in the vdW gap between the Te layers in p-type Bi_(0.3)Sb_(1.7)Te_(3)(BST)for further improving thermoelectrics.The vdW-related defects(including extrinsic interstitial and intrinsic defects)induced by Ga intercalation can not only modulate the carrier concentration but also enhance the texture,thereby yielding excellent electrical properties,which are reflected in the power factor PF~4.43 mW·m^(-1)·K^(-2).Furthermore,the intercalation of Ga produces multi-scale lattice imperfections such as point defects,Te precipitations,and nanopores,realizing the low lattice thermal conductivity in BST-Ga samples.Ultimately,a peak zT~1.1 at 373 K is achieved in the BST-1%Ga sample and greatly improved by~22%compared to the pristine BST.The weak bonding of vdW interlayer interaction can boost the synergistic effect for advancing BST-based or other layered thermoelectrics.
基金Project supported by the National Key Research and Development Program of China (Grant Nos. 2018YFA0702100and 2022YFB3803900)the Joint Funds of the National Natural Science Foundation of China and the Chinese Academy of Sciences (CAS)’ Large-Scale Scientific Facility (Grant No. U1932106)the Sichuan University Innovation Research Program of China (Grant No. 2020SCUNL112)。
文摘AgCrSe2-based compounds have attracted much attention as an environmentally friendly thermoelectric material in recent years due to the intriguing liquid-like properties.However,the ultra-low carrier concentration and the high Ag_(Cr)deep-level defects limit the overall thermoelectric performance.Here,we successfully introduced Pb into Ag-deficient Ag_(0.97)CrSe_(2) alloys to tune the carrier concentration across a broad temperature range.The Pb^(2+) as an acceptor dopant preferentially occupies Cr sites,boosting the hole carrier concentration to 1.77×10^(19) cm^(-3) at room temperature.Furthermore,the Pb strongly inhibits the creation of intrinsic Ag_(Cr) defects,weakens the increased thermal excited ionization with the increasing temperature and slowed the rising trend of the carrier concentration.The designed carrier concentration matches the theoretically predicted optimized one over the entire temperature range,leading to a remarkable enhancement in power factor,especially the maximum power factor of ~500 μW·m^(-1)·K^(-2) at 750 K is superior to most previous results.Additionally,the abundant point defects promote phonon scattering,thus reducing the lattice thermal conductivity.As a result,the maximum figure of merit zT(~0.51 at 750 K) is achieved in Ag_(0.97)Cr_(0.995)Pb_(0.005)Se_(2).This work confirms the feasibility of manipulating deep-level defects to achieve temperature-dependent optimal carrier concentration and provides a valuable guidance for other thermoelectric materials.
基金the National Natural Science Foundation of China(Grant No.11774416)the Fundamental Research Funds for the Central Universities(Grant Nos.2017XKZD08 and 2015XKMS081)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX202039)the Assistance Program for Future Outstanding Talents of China University of Mining and Technology(Grant No.2020WLJCRCZL063)。
文摘Nonisovalent(GaN)_(1-x)(ZnO)_(x)alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap.Unfortunately,the lack of two-dimensional(2D)configurations as well as complete stoichiometries hinders to further explore the thermal transport,thermoelectrics,and adsorption/permeation.We identify that multilayer(GaN)_(1-x)(ZnO)_(x)stabilize as wurtzite-like Pm-(GaN)_(3)(ZnO)_(1),Pmc2_(1)-(Ga N)_(1)(ZnO)_(1),P3m1-(GaN)_(1)(ZnO)_(2),and haeckelite C2/m-(GaN)_(1)(ZnO)_(3)via structural searches.P3m1-(GaN)_(1)(ZnO)_(2)shares the excellent thermoelectrics with the figure of merit ZT as high as 3.08 at 900 K for the p-type doping due to the ultralow lattice thermal conductivity,which mainly arises from the strong anharmonicity by the interlayer asymmetrical charge distributions.The p–d coupling is prohibited from the group theory in C2/m-(Ga N)_(1)(ZnO)_(3),which thereby results in the anomalous band structure versus Zn O composition.To unveil the adsorption/permeation of H^(+),Na^(+),and OH^(-)ions in AA-stacking configurations,the potential wells and barriers are explored from the Coulomb interaction and the ionic size.Our work is helpful in experimental fabrication of novel optoelectronic and thermoelectric devices by 2D(GaN)_(1-x)(ZnO)_(x)alloys.
基金Funded by Open Foundation of State Key Laboratory of Ad-vanced Technology for Materials Synthesis and Processing, Wuhan University of Technology.
文摘The density junction theory and discrete variation method ( DFT - DVM) was used to study correlation between composition, structure, chemical bond, and property of thermoelectrics of Bi-Sb-Te series. 8 models of Bi20-xSbxTe32(x = 0,2,6,8,12,14,18 and 20) were calculated. The results show that there is less difference in the ionic bonds between Te( I)-Bi(Sb) and Te(Ⅱ)-Bi(Sb) , but the covalent bond of Te(Ⅰ)-Bi( Sb ) is stronger than that of Te(Ⅱ)-Bi( Sb ) . The interaction between Te(Ⅰ) and Te(Ⅰ) in different layers is the weakest and the interaction should be Van Der Wools power. The charge of Sb is lower than that of Bi, and the ionic bond of Te-Sb is weaker than that of Te-Bi. The covalent bond of Te-Sb is also weaker than that of Te-Bi. Therefore, the thermoelectric property may be imfiroved by adjusting the electrical conductivity and thermal conductivity through changing the composition in the compounds of Bi-Sb-Te. The calculated results are consistent with the experiments.
基金supported by research grants from the National Key R&D Program of China(grant no.2023YFB4704000)National Natural Science Foundation of China(NSFC+3 种基金grant no.52203211)Fundamental Research Funds for the Central Universities,China(grant no.2024CDJZCQ-005)Exceptional Young Talents Project(grant no.cstc2021ycjh-bgzxm0334)Financial support(grant no.IDH2203003Y)from Fudan University。
文摘Ionic thermoelectricity(i-TE),as a new energy conversion and storage technology,has been widely discussed by the academic community.As one of the representatives of low-grade thermal energy recovery,i-TE has made remarkable progress and become an influential research direction in the energy field.Among them,thermoelectric ionogels have a wide range of applications in the field of energy recovery and utilization due to their excellent flexibility,stability,and thermoelectric conversion ability,providing many application possibilities for such materials.The development of highly efficient and stable ionic thermoelectric devices is largely dependent on the development of new materials and structural designs.This paper focuses on the recent strategies for improving the efficiency of thermoelectric conversion in the field of ionic thermoelectric gels,including new methods for material design,structural optimization,and innovative developments in the application of thermoelectric materials.The evaluation indicators of thermoelectric conversion efficiency are discussed,including ionic thermal voltage,ionic conductivity and power output,ductility,and self-healing properties.Additionally,various application devices based on thermoelectric materials with excellent thermoelectric conversion properties are highlighted.Further,different challenges and strategies that need to be addressed are presented in the hope of providing inspiration and guidance for the commercialization of i-TE.
基金supported by the Australian Research Council and QUT Capacity Building Professor ProgramL Q F acknowledges the financial support from the National Natural Science Foundation of China(No.52272040).
文摘Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight,compactness,noise-free operation,and precision reliability,wearable thermoelectrics show great potential for diverse applications.Among them,weavable thermoelectrics,a subclass with inherent flexibility,wearability,and operability,find utility in harnessing waste heat from irregular heat sources.Given the rapid advancements in this field,a timely review is essential to consolidate the progress and challenge.Here,we provide an overview of the state of weavable thermoelectric materials and devices in wearable smart textiles,encompassing mechanisms,materials,fabrications,device structures,and applications from recent advancements,challenges,and prospects.This review can serve as a valuable reference for researchers in the field of flexible wearable thermoelectric materials and devices and their applications.
文摘Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].However,despite widespread applications,thermoelectric technology remains constrained by material performance[2].
基金National Key Research and Development Program of China,Grant/Award Number:2022YFA1203600National Natural Science Foundation of China,Grant/Award Numbers:51772215,52022068,52102292,T2125008+1 种基金Innovation Program of Shanghai Municipal Education Commission,Grant/Award Number:2021-01-07-00-07-E00096Fundamental Research Funds for the Central Universities。
文摘The crystal-structure symmetry in real space can be inherited in the reciprocal space,making high-symmetry materials the top candidates for thermoelectrics due to their potential for significant electronic band degeneracy.A practical indicator that can quantitatively describe structural changes would help facilitate the advanced thermoelectric material design.In face-centered cubic structures,the spatial environment of the same crystallographic plane family is isotropic,such that the distances between the close-packed layers can be derived from the atomic distances within the layers.Inspired by this,the relationship between inter-and intra-layer geometric information can be used to compare crystal structures with their desired cubic symmetry.The close-packed layer spacing was found to be a practical guideline of crystal structure symmetry in IV-VI chalcogenides and I-V-VI_(2) ternary semiconductors,both of which are historically important thermoelectrics.The continuous structural evolution toward high symmetry can be described by the layer spacing when temperature or/and composition change,which is demonstrated by a series of pristine and alloyed thermoelectric materials in this work.The layerspacing-based guideline provides a quantitative pathway for manipulating crystal structures to improve the electrical and thermal properties of thermoelectric materials.
基金This work was supported by the National Natural Science Foundation of China(11974208,52172212)Shandong Provincial Science Foundation(ZR2020YQ05,ZR2021YQ03,ZR2023JQ001)+1 种基金The authors acknowledge financial support from the program of“Young Scientists of Taishan Scholar”(No.tsqn202211128,tsqn202306184)“Distinguished Expert of Taishan Scholar”(No.tstp20221124).
文摘Exploring high-performance thermoelectric materials with improved mechanical properties is important for broadening the application scope and the assembly requirement of stable devices.This work presents an effective strategy to discover hard thermoelectric material by inserting foreign atoms in the rigid covalent framework.We demonstrate this in boron-carbon clathrate VII structure,showing a promising candidate for highly efficient thermoelectric energy conversion,especially with Y atom filled in the cage,with a peak zT of 0.73 at 1,000 K.The ab initio calculations indicate that YB_(3)C_(3) system has low lattice thermal conductivity of 4.5 W/(m·K)at 1,000 K due to the strong rattling of encaged Y atom.The strongly covalent framework provides highly degenerate band structures consisting of heavy and light electron pockets,which can maintain high carrier mobility arising from small effective mass and thus large group velocity.Consequently,high power factor can be achieved in YB_(3)C_(3) for both electron and hole doping.In addition,it exhibits well mechanical properties and a Vickers hardness of 23.7 GPa because of the strong covalent boron-carbon framework.This work provides a novel avenue for the search of high-performance thermoelectric materials with excellent mechanical properties,based on boron-carbon clathrate structure.
基金supported by National Natural Science Foundation of China(52250090,52371208,51571007,51772012)the Beijing Natural Science Foundation(JQ18004),111 Project(B17002)L D Z appreciates the National Science Fund for Distinguished Young Scholars(51925101).
文摘Recently,off-centering behavior has been discovered in a series of thermoelectric materials.This behavior indicates that the constituent atoms of the lattice displace from their coordination centers,leading to the locally distorted state and local symmetry breaking,while the material still retains its original crystallographic symmetry.This effect has been proved to be the root cause of ultralow thermal conductivity in off-centering materials,and is considered as an effective tool to regulate the thermal conductivity and improve the thermoelectric performance.Herein,we present a collection of recently discovered off-centering compounds,discuss their electronic origins and local coordination structures,and illuminate the underlying mechanism of the off-centering effect on phonon transport and thermal conductivity.This paper presents a comprehensive view of our current understanding to the off-centering effect,and provides a new idea for designing high performance thermoelectrics.
基金supported by the National Key Research and Development Program of China(2021YFB3502200,2018YFB0703600,and 2019YFA0704901)the National Natural Science Foundation of China(52172216,92163212,and 12174242)+3 种基金the Key Research Project of Zhejiang Laboratory(2021PE0AC02)Zhang W also acknowledges the support from Guangdong Innovation Research Team Project(2017ZT07C062)Guangdong Provincial Key-Lab program(2019B030301001)Shenzhen Municipal Key-Lab program(ZDSYS20190902092905285).
文摘Following the Materials Genome Initiative project,materials research has embarked a new research paradigm centered around material repositories,significantly accelerating the discovery of novel materials,such as thermoelectrics.Thermoelectric materials,capable of directly converting heat into electricity,are garnering increasing attention in applications like waste heat recovery and refrigeration.To facilitate research in this emerging paradigm,we have established the Materials Hub with Three-Dimensional Structures(MatHub-3d)repository,which serves as the foundation for high-throughput(HTP)calculations,property analysis,and the design of thermoelectric materials.In this review,we summarize recent advancements in thermoelectric materials powered by the MatHub-3d,specifically HTP calculations of transport properties and material design on key factors.For HTP calculations,we develop the electrical transport package for HTP purpose,and utilize it for materials screening.In some works,we investigate the relationship between transport properties and chemical bonds for particular types of thermoelectric compounds based on HTP results,enhancing the fundamental understanding about interested compounds.In our work associated with material design,we primarily utilize key factors beyond transport properties to further expedite materials screening and speedily identify specific materials for further theoretical/experimental analyses.Finally,we discuss the future developments of the MatHub-3d and the evolving directions of database-driven thermoelectric research.
基金National Natural Science Foundation of China(Nos.52172249,51976215,and 51973034)Scientific Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20200017)+3 种基金Chinese Academy of Sciences Talents Program(E2290701)Funding of Innovation Academy for Light-duty Gas Turbine,Chinese Academy of Sciences(CXYJJ21-ZD-02)Fundamental Research Funds for the Central Universities(2232020G-01 and 19D110106)Special Fund Project of Carbon Peaking Carbon Neutrality Science and Technology Innovation of Jiangsu Province(BE2022011).
文摘With the development and prosperity of Internet of Things(IoT)technology,wearable electronics have brought fresh changes to our lives.The demands for low power consumption and mini-type wearable power systems for wearable electronics are more urgent than ever.Thermoelectric materials can efficiently convert the temperature difference between body and environment into electrical energy without the need for mechanical components,making them one of the ideal candidates for wearable power systems.In recent years,a variety of high-performance thermoelectric materials and processes for the preparation of large-scale single-fiber devices have emerged,driving the application of flexible fiber-based thermoelectric generators.By weaving thermoelectric fibers into a textile that conforms to human skin,it can achieve stable operation for long periods even when the human body is in motion.In this review,the complete process from thermoelectric materials to single-fiber/yarn devices to thermoelectric textiles is introduced comprehensively.Strategies for enhancing thermoelectric performance,processing techniques for fiber devices,and the wide applications of thermoelectric textiles are summarized.In addition,the challenges of ductile thermoelectric materials,system integration,and specifications are discussed,and the relevant developments in this field are prospected.
基金financially supported by the Guangdong Basic and Applied Basic Research Foundation(2022A1515110296,2022A1515110432)the Shenzhen Science and Technology Program(20231120171032001)the National Natural Science Foundation of China(No.52242305).
文摘Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great challenge.Herein,a highly elastic,flame-retardant and high-temperature-resistant TE aerogel,made of poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube(PEDOT:PSS/SWCNT)composites,has been fabricated,displaying attractive compression-induced power factor enhancement.The as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range monitoring.Subsequently,a flexible TE generator is assembled,consisting of 25 aerogels connected in series,capable of delivering a maximum output power of 400μW when subjected to a temperature difference of 300 K.This demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature pipelines.Moreover,the designed self-powered wearable sensing glove can realize precise wide-range temperature detection,high-temperature warning and accurate recognition of human hand gestures.The aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning capability.Benefitting from these desirable properties,the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring,industrial overheat warning,waste heat energy recycling and even wearable healthcare.
基金supported by the grants(51973027 and 52003044)from the National Natural Science Foundation of Chinathe Fundamental Research Funds for the Central Universities(2232023A-05)+4 种基金the International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(21130750100)Major Scientific and Technological Innovation Projects of Shandong Province(2021CXGC011004)This work has also been supported by the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF2216)the Donghua University Distinguished Young Professor Program to Prof.Liming Wangthe Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(CUSF-DH-D-2022040)to Xinyang He.
文摘The rapid development of the global economy and population growth are accompanied by the production of numerous waste textiles.This leads to a waste of limited resources and serious environmental pollution problems caused by improper disposal.The rational recycling of wasted textiles and their transformation into high-value-added emerging products,such as smart wearable devices,is fascinating.Here,we propose a novel roadmap for turning waste cotton fabrics into three-dimensional elastic fiber-based thermoelectric aerogels by a one-step lyophilization process with decoupled self-powered temperature-compression strain dual-parameter sensing properties.The thermoelectric aerogel exhibits a fast compression response time of 0.2 s,a relatively high Seebeck coefficient of 43μV·K^(-1),and an ultralow thermal conductivity of less than 0.04 W·m^(-1)·K^(-1).The cross-linking of trimethoxy(methyl)silane(MTMS)and cellulose endowed the aerogel with excellent elasticity,allowing it to be used as a compressive strain sensor for guessing games and facial expression recognition.In addition,based on the thermoelectric effect,the aerogel can perform temperature detection and differentiation in self-powered mode with the output thermal voltage as the stimulus signal.Furthermore,the wearable system,prepared by connecting the aerogel-prepared array device with a wireless transmission module,allows for temperature alerts in a mobile phone application without signal interference due to the compressive strains generated during gripping.Hence,our strategy is significant for reducing global environmental pollution and provides a revelatory path for transforming waste textiles into high-value-added smart wearable devices.
基金funded by the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation program(grant agreement no.755655,ERC-StG 2017 project 2D-TOPSENSE)the Ministry of Science and Innovation(Spain)through the project PID2020-115566RB-I00+7 种基金the Distinguished Scientist Fellowship Program(DSFP)at King Saud University for partial funding of this workfinancial support from the Agencia Estatal de Investigación of Spain(Grants PID2019-106820RB,RTI2018-097180-B-100,and PGC2018-097018-B-I00)the Junta de Castilla y León(Grants SA256P18 and SA121P20),including funding by ERDF/FEDERfinancial support from Universidad Complutense de Madrid and European Commission(MSCA COFUND UNA4CAREER grant.Project number 4129252)financial support from MICINN(Spain)through the program Juan de la Cierva-Incorporaciónthe financial support of the Spanish Ministry of Industry and Competitiveness to the project MAT2017-84496-Rfinancial support from the Ministry of Science and Innovation(Spain)through the project RT2018-099794-B-100financial support from the Ministry de Universities(Spain)(Ph.D.contract FPU19/04224)
文摘We present a method to fabricate handcrafted thermoelectric devices on standard office paper substrates.The devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(N-type semiconductors),deposited by simply rubbing powder of these materials against paper.The thermoelectric properties of these semiconducting films revealed maximum Seebeck coefficients of(+1.32±0.27)mV K^(-1)and(-0.82±0.15)mV K^(-1)for WS_(2)and TiS_(3),respectively.Additionally,Peltier elements were fabricated by interconnecting the P-and N-type films with graphite electrodes.A thermopower value up to 6.11 mV K^(-1)was obtained when the Peltier element were constructed with three junctions.The findings of this work show proof-of-concept devices to illustrate the potential application of semiconducting van der Waals materials in future thermoelectric power generation as well as temperature sensing for low-cost disposable electronic devices.
基金National Natural Science Foundation of China(Grant Nos.62335006,62022032,62275065,and 61875047)Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University),Ministry of Education(Grant No.OEIAM202202)Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2023011).
文摘A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manuscript.An erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further enhanced.The optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,respectively.The target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip QTF.An improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF.
基金supported by the National Natural Science Foundation of China(No.62122002)the Project of City University of Hong Kong(Nos.9667221,9678274,and 9680322)+1 种基金as part of the InnoHK Project on Project 2.2—AI-based 3D ultrasound imaging algorithm at Hong Kong Centre for Cerebro-Cardiovascular Health Engineering(COCHE)the Project of Research Grants Council of the Hong Kong Special Administrative Region(Nos.11213721,11215722,and 11211523)。
文摘The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.
基金supported by the National Natural Science Foundation of China(51973027 and 52003044)the Fundamental Research Funds for the Central Universities(2232020A-08)+4 种基金International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(21130750100)the Major Scientific and Technological Innovation Projects of Shandong Province(2021CXGC011004)supported by the Chang Jiang Scholars Program and the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-03-E00023)to Prof.Xiaohong Qinthe State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF2216)and Donghua University(DHU)Distinguished Young Professor Program to Prof.Liming Wangthe Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(CUSF-DH-D-2022040)to Xinyang He.
文摘Flexible thermoelectric materials play an important role in smart wearables,such as wearable power generation,self-powered sensing,and personal thermal management.However,with the rapid development of Internet of Things(IoT)and artificial intelligence(AI),higher standards for comfort,multifunctionality,and sustainable operation of wearable electronics have been proposed,and it remains challenging to meet all the requirements of currently reported thermoelectric devices.Herein,we present a multifunctional,wearable,and wireless sensing system based on a thermoelectric knitted fabric with over 600 mm·s^(-1)air permeability and a stretchability of 120%.The device coupled with a wireless transmission system realizes self-powered monitoring of human respiration through an mobile phone application(APP).Furthermore,an integrated thermoelectric system was designed to combine photothermal conversion and passive radiative cooling,enabling the characteristics of being powered by solar-driven in-plane temperature differences and monitoring outdoor sunlight intensity through the APP.Additionally,we decoupled the complex signals of resistance and thermal voltage during deformation under solar irradiation based on the anisotropy of the knitted fabrics to enable the device to monitor and optimize the outdoor physical activity of the athlete via the APP.This novel thermoelectric fabricbased wearable and wireless sensing platform has promising applications in next-generation smart textiles.
基金the financial support from the National Natural Science Foundation of China(Grant No.52171221)the National Key Research and Development Program of China(Grant No.2019YFA0704900)the support from the Core Facility of Wuhan University for their assistance with EPMA analysis
文摘The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric performance.However,the role of such a ferroelectric-like structural distortion on its transport properties remains unclear.Herein,we performed a systematic study on the crystal structure and electronic band structure evolutions of Ge_(1-x)Sn_(x)Te alloys where the degree of ferroelectric distortion is continuously tuned.It is revealed that the band gap is maximized while multiple valence bands are converged at x=0.6,where the ferroelectric distortion is the least but still works.Once undistorted,the band gap is considerably reduced,and the valence bands are largely separated again.Moreover,near the ferro-to-paraelectric phase transition Curie temperature,the lattice thermal conductivity reaches its minima because of significant lattice softening enabled by ferroelectric instability.We predict a peak ZT value of 2.6 at 673 K inα-GeTe by use of proper dopants which are powerful in suppressing the excess hole concentrations but meanwhile exert little influence on the ferroelectric distortion.