Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny forces.This article introduces a low-cost and easy-fabricat...Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny forces.This article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure sensors.By embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its surface.On this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination curves.Looking ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.展开更多
Flexible electrochromic energy storage devices(FECESDs)for powering flexible electronics have attracted considerable attention.Silver nanowires(AgNWs)are one kind of the most promising flexible transparent electrodes(...Flexible electrochromic energy storage devices(FECESDs)for powering flexible electronics have attracted considerable attention.Silver nanowires(AgNWs)are one kind of the most promising flexible transparent electrodes(FTEs)materials for the emerging flexible devices.Currently,fabricating FECESD based on AgNWs FTEs is still hindered by their intrinsic poor electrochemical stability.To address this issue,a hybrid AgNWs/Co(OH)_(2)/PEDOT:PSS electrode is proposed.The PEDOT:PSS could not only improve the resistance against electrochemical corrosion of AgNWs,but also work as functional layer to realize the color-changing and energy storage properties.Moreover,the Co(OH)_(2)interlayer further improved the color-changing and energy storage performance.Based on the improvement,we assembled the symmetrical FECESDs.Under the same condition,the areal capacitance(0.8 mF cm^(−2))and coloration efficiency(269.80 cm^(2)C−1)of AgNWs/Co(OH)_(2)/PEDOT:PSS FECESDs were obviously higher than AgNWs/PEDOT:PSS FECESDs.Furthermore,the obtained FECESDs exhibited excellent stability against the mechanical deformation.The areal capacitance remained stable during 1000 times cyclic bending with a 25 mm curvature radius.These results demonstrated the broad application potential of the AgNWs/Co(OH)_(2)/PEDOT:PSS FECESD for the emerging portable and multifunctional electronics.展开更多
The electronic product has gravitated towards component miniaturization and integration, employment of lead-free materials, and low-temperature soldering processes. Noble-metal aerogels have drawn increasing attention...The electronic product has gravitated towards component miniaturization and integration, employment of lead-free materials, and low-temperature soldering processes. Noble-metal aerogels have drawn increasing attention for high conduction and low density. However,the noble metal aerogels with outstanding solderability were rarely studied. This work has successfully synthesized an aerogel derived from silver nanowires(AgNWs) using a liquid phase reduction method. It is found that the noble metal aerogels can be made into diverse aerogel preformed soldering sheets. The influence of bonding temperature(150-300 ℃), time(2-20 min), and pressure(5-20 MPa) on the joint strength of the AgNWs aerogel affixed to electroless nickel/silver copper plates were investigated. Additionally, the AgNWs aerogel displays almost the same shear strength for substrates of various sizes. In a word, this study presents a flux-free, high-strength, and adaptable soldering structural material.展开更多
Transparent electrode based on silver nanowires(Ag NWs) emerges as an outstanding alternative of indium tin oxide film especially for flexible electronics. However, the conductivity of Ag NWs transparent electrode is ...Transparent electrode based on silver nanowires(Ag NWs) emerges as an outstanding alternative of indium tin oxide film especially for flexible electronics. However, the conductivity of Ag NWs transparent electrode is still dramatically limited by the contact resistance between nanowires at high transmittance. Polyvinylpyrrolidone(PVP) layer adsorbed on the nanowire surface acts as an electrically insulating barrier at wire–wire junctions, and some devastating post-treatment methods are proposed to reduce or eliminate PVP layer, which usually limit the application of the substrates susceptible to heat or pressure and burden the fabrication with high-cost, time-consuming, or inefficient processes. In this work, a simple and rapid pre-treatment washing method was proposed to reduce the thickness of PVP layer from 13.19 to0.96 nm and improve the contact between wires. Ag NW electrodes with sheet resistances of 15.6 and 204 X sq-1have been achieved at transmittances of 90 and 97.5 %, respectively. This method avoided any post-treatments and popularized the application of high-performance Ag NW transparent electrode on more substrates. The improved Ag NWs were successfully employed in a capacitive pressure sensor with high transparency, sensitivity, and reproducibility.展开更多
Three-dimensional(3D)electrically conductive micro/nanostructures are now a key component in a broad range of research and industry fields.In this work,a novel method is developed to realize metallic 3D micro/nanostru...Three-dimensional(3D)electrically conductive micro/nanostructures are now a key component in a broad range of research and industry fields.In this work,a novel method is developed to realize metallic 3D micro/nanostructures with silver-thiol-acrylate composites via two-photon polymerization followed by femtosecond laser nanojoining.Complex 3D micro/nanoscale conductive structures have been successfully fabricated with∼200 nm resolution.The loading of silver nanowires(AgNWs)and joining of junctions successfully enhance the electrical conductivity of the composites from insulating to 92.9 Sm^−1 at room temperature.Moreover,for the first time,a reversible switching to a higher conductivity is observed,up to∼10^5Sm^−1 at 523 K.The temperature-dependent conductivity of the composite is analyzed following the variable range hopping and thermal activation models.The nanomaterial assembly and joining method demonstrated in this study pave a way towards a wide range of device applications,including 3D electronics,sensors,memristors,micro/nanoelectromechanical systems,and biomedical devices,etc.展开更多
Large-scale silver nanowires with controlled aspect ratio were synthesized via reducing silver nitrate with 1, 2- propanediol in the presence of poly （vinyl pyrrolidone） （PVP）. Scanning electron microscopy, transm...Large-scale silver nanowires with controlled aspect ratio were synthesized via reducing silver nitrate with 1, 2- propanediol in the presence of poly （vinyl pyrrolidone） （PVP）. Scanning electron microscopy, transmission electron microscopy and x-ray powder diffraction were employed to characterize these silver nanowires. The diameter of the silver nanowires can be readily controlled in the range of 100 to 400 nm by varying the experimental conditions. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results show that there exists no chemical bond between the silver and the nitrogen atoms. The interaction between PVP and silver nanowires is mainly through the oxygen atom in the carbonyl group.展开更多
Two kinds of silver nanowires(100 nm in diameter, 20 μm and 100 μm in length) are prepared. The thermo-physical characteristics, viscosity, and photothermal conversion performance of the silver nanowires(AgNWs)conta...Two kinds of silver nanowires(100 nm in diameter, 20 μm and 100 μm in length) are prepared. The thermo-physical characteristics, viscosity, and photothermal conversion performance of the silver nanowires(AgNWs)contained ethylene glycol nanofluids are investigated in detail. It is found that thermal conductivity of 100 μm AgNWs contained nanofluids is higher than that of 20 μm AgNWs with the same diameters of 100 nm. Viscosity test shows that the nanofluid is a Newtonian fluid, and the longer silver nanowires, the greater viscosity. In addition, photothermal conversion efficiency of silver nanowires contained nanofluid is studied. We can observe that the 100 μm AgNWs contained nanofluid has a higher photothermal conversion efficiency than that containing 20 μm AgNWs. Moreover, we find that there is a certain correlation between heat transfer and photothermal conversion of nanofluid. It demonstrates that the high heat transfer property of nanofluid will benefit for its photothermal conversion efficiency and the mechanism is proposed. This work provides a new idea to improve photothermal conversion efficiency. We can choose materials with high thermal conductivity and strong light absorption ability to enhance the photothermal conversion performance of nanofluids.展开更多
The change of conductivity and transparency of silver nanowire （AgNW） films by adding silver nano-particles （AgNPs） onto their surface is studied. The results show that the conductivity of the AgNW film is greatly...The change of conductivity and transparency of silver nanowire （AgNW） films by adding silver nano-particles （AgNPs） onto their surface is studied. The results show that the conductivity of the AgNW film is greatly improved with its sheet resistance reduced about 78. 7% to 51.9Ω/sq, and there is no obvious reduction of the transmittance. Further studies show that there is a self-assembling process pushing the AgNPs to concentrate at the intersecting points between AgNWs to weld them, which would reduce the intersection resistance between the AgNWs. This self-assembling behavior is led by the surface interactivities among the dispersing liquid of AgNPs, the surface of the substrate and AgNWs when the dispersing liquid is drying.展开更多
Using propagating surface plasmons （SPs） on a silver nanowire （NW）, we demonstrate that a focused laser light at the end of the silver NW can excite a single quantum dot （QD） microns away from the excitation spo...Using propagating surface plasmons （SPs） on a silver nanowire （NW）, we demonstrate that a focused laser light at the end of the silver NW can excite a single quantum dot （QD） microns away from the excitation spot. The QD-NW interaction allows the excited QD convert part of its energy into propagating SPs, which then can be detected at remote sites. Simultaneous multi-QD remote excitation and remote detection can also be realized. Furthermore, the tight confinement of the propagating SPs around the NW surface enables the selective excitation of QDs very close in space, which cannot be realized under the conventional excitation condition. This remote excitation and remote detection approach may find applications in optical imaging and the sensing of chemical and biological systems.展开更多
Silver nanowire（AgNW） networks have been demonstrated to exhibit superior transparent and conductive performance over that of indium-doped tin oxide（ITO） and have been proposed to replace ITO, which is currently w...Silver nanowire（AgNW） networks have been demonstrated to exhibit superior transparent and conductive performance over that of indium-doped tin oxide（ITO） and have been proposed to replace ITO, which is currently widely used in optoelectronic devices despite the scarcity of indium on Earth. In this paper, the current spreading and enhanced transmittance induced by AgNWs, which are two important factors influencing the light output power, were analyzed. The enhanced transmittance was studied by finite-difference time-domain simulation and verified by cathodoluminescence measurements.The enhancement ratio of the light output power decreased as the Ga P layer thickness increased, with enhancement ratio values of 79%, 52%, and 15% for Ga P layer thicknesses of 0.5 μm, 1 μm, and 8 μm, respectively, when an AgNW network was included in Al Ga In P light-emitting diodes. This was because of the decreased current distribution tunability of the AgNW network with the increase of the Ga P layer thickness. The large enhancement of the light output power was caused by the AgNWs increasing carrier spread out of the electrode and the enhanced transmittance induced by the plasmonic AgNWs. Further decreasing the sheet resistance of AgNW networks could raise their light output power enhancement ratio.展开更多
The effect of an external magnetic field on the preparation of silver nanowires was studied. The silver nanowires were synthesized using solid electrolyte RbAg4I5 thin films by applying both a direct current （DC） el...The effect of an external magnetic field on the preparation of silver nanowires was studied. The silver nanowires were synthesized using solid electrolyte RbAg4I5 thin films by applying both a direct current （DC） electric field and a magnetic field. The RbAg4I5 thin films, which were prepared by deposition at room temperature and atmospheric pressure on a NaCI substrate, were used for the transfer of Ag^＋ ions between two Ag electrodes during the preparation process. When only the DC electric field is applied, the silver ions migrate toward the cathode. On the edge of the silver film at the cathode the Ag^＋ ions congregate to form aligned nanowires. If the magnetic field is also applied perpendicular to the DC electric field, the morphology of the nanowires can be controlled by rotating the sample in the magnetic field. Experimental results show that the growth of the silver nanowires is determined by the Ag^＋ ionic flux.展开更多
High-haze flexible transparent conductive polymethyl methacrylate （PMMA） films embedded with silver nanowires （AgNWs） are fabricated by a low-cost and simple process. The volatilization rate of the solvent in PMMA...High-haze flexible transparent conductive polymethyl methacrylate （PMMA） films embedded with silver nanowires （AgNWs） are fabricated by a low-cost and simple process. The volatilization rate of the solvent in PMMA solution affects the surface microstructures and morphologies, which results in different haze factors of the composite films. The areal mass density of AgNW shows a significant influence on the optical and electrical properties of composite films. The AgNW/PMMA transparent conductive films with the sheet resistance of 5.5Ω sq ^-1 exhibit an excellent performance with a high haze factor of 81.0% at 550？nm.展开更多
Conductive fibers(CFs)with features of high conductivity,stretchability,self-healability,and electromechanical stability are key components of the increasingly popular wearable electronics.However,since the lack of st...Conductive fibers(CFs)with features of high conductivity,stretchability,self-healability,and electromechanical stability are key components of the increasingly popular wearable electronics.However,since the lack of structural design of conductive network and interfacial interaction between soft polymer and conductive additives,it is still hard to enable CFs to meet above requirements.Here,we describe a facial drawing method from a hydrogel reservoir which is remolded into ultrathin and stretchable CFs with excellent multi-responsive self-healability.The hydrogel reservoir was fabricated in synergy of an ice-templating method and in situ polymerization using the assembled framework as a crosslinker.Relying on the effective fabrication mechanism,the diameter of CFs could be well-tuned from 90 to 400μm by adjusting the dipping depth of the glass rod,accompanied with conductivity increased from 0.75 to 2.5 S/m.Since the hierarchical network structure was well maintained in the CFs,professional performances have been proved on the stretchability and electromechanical stability.The presence of massive hydrogen bonding and Ag–S bond enabled the CFs with excellent self-healability under the conditions of contact,electric field,and near infrared light,respectively.Excitingly,the CFs with high sensing property could be integrated into an advanced textile sensor through an effective healing-induced integration strategy,demonstrating its great potentials as superior two-dimensional(2D)electronic skins.展开更多
Silver nanowire(AgNW)networks hold great promises as next-generation flex-ible transparent electrodes(FTEs)for high-performance flexible optoelectronic devices.However,achieving large-area flexible AgNW network electr...Silver nanowire(AgNW)networks hold great promises as next-generation flex-ible transparent electrodes(FTEs)for high-performance flexible optoelectronic devices.However,achieving large-area flexible AgNW network electrodes with low sheet resistance,high optical transmittance,and a smooth surface remains a grand challenge.Here,we report a straightforward and cost-effective roll-to-roll method that includes interface assembly/wetting-induced climbing transfer,nanowelding,and washing processess to fabricate flexible ordered lay-ered AgNW electrodes with high network uniformity.By manipulating the stacking number of the interfacially assembled AgNW monolayer,we can pre-cisely tailor and balance the transparency and the conductivity of the elec-trodes,achieving an exceptional Figure of Merit(FoM)value of 862.Moreover,the ordered layered structure enhances surface smoothness,compared with randomly arranged structures.To highlight the potential of these ordered lay-ered AgNW network electrodes in flexible optoelectronic devices,we success-fully employ them as highly sensitive strain sensors,large-area flexible touch screens,and flexible smart windows.Overall,this work represents a substantial advance toward high-performance FTEs over large areas,opening up exciting opportunities for the development of advanced optoelectronic devices.展开更多
Understanding the structural stability of nanomaterials such as nanowires is imperative for their practical applications.Here,using single-shot ultrafast transmission electron microscopy,we captured the Plateau-Raylei...Understanding the structural stability of nanomaterials such as nanowires is imperative for their practical applications.Here,using single-shot ultrafast transmission electron microscopy,we captured the Plateau-Rayleigh instability behavior of silver nanowires decomposing into silver nanoparticles upon laser irradiation on nanosecond time scales.We found that this dynamic process can be accelerated by a factor of 10 through increasing the peak laser fluence from 6.03 to 14.60 mJ/cm^(2).Moreover,by comparing the laser fluence required to initiate the Plateau-Rayleigh instability in silver nanowires on carbon and Formvar membranes,it was found that the main driving force for the Plateau-Rayleigh instability in this study was substrate heating.Finite element analysis and molecular dynamics simulations are also applied to estimate the temperature jump of the nanowires and atomistic behavior,respectively.In addition,the complex motions of silver nanowires under laser irradiation were systematically investigated by combining the results of ultrafast transmission electron microscopy with scanning electron microscopy characterizations and were determined to be related to nanowire-membrane interactions or pre-existing stresses on the nanowires,which in turn demonstrated the potential of ultrafast transmission electron microscopy for the characterization of nanomaterials and devices under extreme conditions.展开更多
Traditional Korean Hanji paper and cotton fabric were introduced as flexible substrates in the fabrication of graphene-coated heaters.Silver nanowires and PEDOT:PSS were added to increase the electrical conductivity o...Traditional Korean Hanji paper and cotton fabric were introduced as flexible substrates in the fabrication of graphene-coated heaters.Silver nanowires and PEDOT:PSS were added to increase the electrical conductivity of the heaters,thereby enhancing their heating performance.The optimal concentrations of silver nanowires and PEDOT:PSS with respect to that of graphene were identified.These active materials were deposited on flexible Hanji/cotton and non-flexible alumina substrates using supersonic spraying.The proposed Hanji-and cotton-based heaters were light,wearable,stretchable,skin-friendly,and biodegradable.The unyielding alumina-based heater exhibited the highest heating temperature of 275°C at 13 V.Wearable heater bendability and stretchability were tested considering multiple bending and stretching cycles.Moreover,water boiling and fabric drying were successfully performed using the alumina-based heater.The supersonic spraying deposition technique was used to produce writable and patternable heaters.展开更多
Stretchable transparent electrode(STE)plays a key role in numerous emerging applications as an indispensable component for future stretchable devices.The embedded STE,as a promising candidate,possesses balanced perfor...Stretchable transparent electrode(STE)plays a key role in numerous emerging applications as an indispensable component for future stretchable devices.The embedded STE,as a promising candidate,possesses balanced performances and facile preparation procedures.However,it still suffers from the defects of conductive materials caused by the transferring,which results in the irreversible failure of devices.In this work,a patternable silver nanowire(AgNW)STE was fabricated by a plasma-enhanced cryo-transferring(PEC-transferring)process.Owing to the plasma-induced sintering,the AgNW network obtained remarkable improvement in robustness,which ensured the intact network after transferring and thus led to superior tensile electrical properties of the STE.Furthermore,serpentine patterns were utilized to optimize the tensile electrical properties of the STE,which achieved a figure of merit of 292.8 and 150%resistance changing under 50%strain.As a practical application,a 4×3 array of the mutual-capacitive type stretchable touch sensors was demonstrated for future touch sensors in stretchable devices.The PEC-transferring process opened a new avenue for patternable embedded STEs and exhibited its high potential in wearable electronics and the Internet of Thing devices.展开更多
Silver nanowires （AgNWs） surrounded by insulating poly（vinylpyrrolidone） have been synthesized by a polyol process and employed as transparent electrodes. The AgNW transparent electrodes can be fabricated by heatt...Silver nanowires （AgNWs） surrounded by insulating poly（vinylpyrrolidone） have been synthesized by a polyol process and employed as transparent electrodes. The AgNW transparent electrodes can be fabricated by heattreatment at about 200 ℃ which forms connecting junctions between AgNWs. Such a heating process is, however, one of the drawbacks of the fabrication of AgNW electrodes on heat-sensitive substrates. Here it has been demonstrated that the electrical conductivity of AgNW electrodes can be improved by mechanical pressing at 25 MPa for 5 s at room temperature. This simple process results in a low sheet resistance of 8.6 Ω/square and a transparency of 80.0%, equivalent to the properties of the AgNW electrodes heated at 200 ℃. This technique makes it possible to fabricate AgNW transparent electrodes on heat-sensitive substrates. The AgNW electrodes on poly（ethylene terephthalate） films exhibited high stability of their electrical conductivities against the repeated bending test. In addition, the surface roughness of the pressed AgNW electrodes is one-third of that of the heat-treated electrode because the AgNW junctions are mechanically compressed. As a result, an organic solar cell fabricated on the pressed AgNW electrodes exhibited a power conversion as much as those fabricated on indium tin oxide electrodes. These findings enable continuous roll-to-roll processing at room temperature, resulting in relatively simple, inexpensive, and scalable processing that is suitable for forthcoming technologies such as organic solar cells, flexible displays, and touch screens.展开更多
Transparent electrodes made of silver nanowires （AgNWs） exhibit higher flexibility when compared to those made of tin doped indium oxide （ITO） and are expected to be applied in plastic electronics. However, these ...Transparent electrodes made of silver nanowires （AgNWs） exhibit higher flexibility when compared to those made of tin doped indium oxide （ITO） and are expected to be applied in plastic electronics. However, these transparent electrodes composed of AgNWs show high haze because the wires cause strong light scattering in the visible range. Reduction of the wire diameter has been proposed as a way to weaken light scattering, although there have seldom been any studies focusing on the haze because of the difficulty involved in controlling the wire diameter. In this report, we show that the haze can be easily reduced by increasing the length of AgNWs with a large diameter. Ultra-long （u-long） AgNWs with lengths in the range of 20-100 μm and a maximum length of 230 μm have been successfully synthesized by adjusting the reaction temperature and the stirring speed of a one-step polyol process. Compared to typical AgNWs （with diameter and length of 70 nm and 10 μm, respectively） and ITO, a transparent electrode consisting of u-long AgNWs 91 nm in diameter demonstrated a low haze of 3.4%-1.6% and a low sheet resistance of 24-109 Ω/sq. at a transmittance of 94%-97%. Even when fabricated at room temperature without any post-treatment, the electrodes composed of u-long AgNWs achieved a sheet resistance of 19 Ω/sq, at a transmittance of 80%, which is six orders of magnitude lower than that of typical AgNWs.展开更多
Contemporary nanostructured transparent electrodes for use in solar cells require high transmittance and high conductivity, dictating nanostructures with high aspect ratios. Optical haze is an equally important yet un...Contemporary nanostructured transparent electrodes for use in solar cells require high transmittance and high conductivity, dictating nanostructures with high aspect ratios. Optical haze is an equally important yet unstudied parameter in transparent electrodes for solar cells that is also determined by the geometry of the nanostructures that compose the electrode. In this work, the effect of the silver nanowire diameter on the optical haze values in the visible spectrum was investigated using films composed of wires with either small diameters （N60 nm） or large diameters （~150 nm）. Finite difference time domain （FDTD） simulations and experimental transmittance data confirm that smaller diameter nanowires form higher performing transparent conducting electrode （TCE） films according to the current figure of merit. While maintaining near constant transmittance and conductivity for each film, however, it was observed experimentally that films composed of silver nanowires with larger diameters have a higher haze factor than films with smaller diameters. This confirms the FDTD simulations of the haze factor for single nanowires with similarly large and small diameters. This is the first record of haze properties for Ag NWs that have been simulated or experimentally measured, and also the first evidence that the current figure of merit for TCEs is insufficient to evaluate their performance in solar cell devices.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.82270819)the Project of Integra-tive Chinese and Western Medicine(Grant No.ZXXT-202206)+1 种基金the National Key Research and Development Program of China(Grant No.2023YFC3606001)the Basic Science Research Project of Renji Hospital(Grant No.RJTI22-MS-015).
文摘Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny forces.This article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure sensors.By embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its surface.On this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination curves.Looking ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.
基金supports from the National Natural Science Foundation of China (Grant No. 52175300)Fundamental Research Funds for the Central Universities (2022FRFK060008)+2 种基金Heilongjiang Touyan Innovation Team Program (HITTY-20190013)Shenzhen Fundamental Research Programs (JCYJ20200925160843002)Start-up fund of SUSTech (Y01256114)
文摘Flexible electrochromic energy storage devices(FECESDs)for powering flexible electronics have attracted considerable attention.Silver nanowires(AgNWs)are one kind of the most promising flexible transparent electrodes(FTEs)materials for the emerging flexible devices.Currently,fabricating FECESD based on AgNWs FTEs is still hindered by their intrinsic poor electrochemical stability.To address this issue,a hybrid AgNWs/Co(OH)_(2)/PEDOT:PSS electrode is proposed.The PEDOT:PSS could not only improve the resistance against electrochemical corrosion of AgNWs,but also work as functional layer to realize the color-changing and energy storage properties.Moreover,the Co(OH)_(2)interlayer further improved the color-changing and energy storage performance.Based on the improvement,we assembled the symmetrical FECESDs.Under the same condition,the areal capacitance(0.8 mF cm^(−2))and coloration efficiency(269.80 cm^(2)C−1)of AgNWs/Co(OH)_(2)/PEDOT:PSS FECESDs were obviously higher than AgNWs/PEDOT:PSS FECESDs.Furthermore,the obtained FECESDs exhibited excellent stability against the mechanical deformation.The areal capacitance remained stable during 1000 times cyclic bending with a 25 mm curvature radius.These results demonstrated the broad application potential of the AgNWs/Co(OH)_(2)/PEDOT:PSS FECESD for the emerging portable and multifunctional electronics.
基金the National Natural Science Foundation of China(Grant No.52075125,No.52105331)the Shenzhen Science and Technology Innovation Committee(Grant No.JCYJ20210324124203009,No.JSGG20201102154600003,No.GXWD20220818163456002)+1 种基金Special Fund for Science and Technology Innovation Strategy of Guangdong Province(Grant No.pdjh2022b0570)Sustainedly Supported Fundation by National Key Laboratory of Science and Technology on Space Microwave under Grant HTKJ2022KL504011,and NIO University Programme(NIO UP).
文摘The electronic product has gravitated towards component miniaturization and integration, employment of lead-free materials, and low-temperature soldering processes. Noble-metal aerogels have drawn increasing attention for high conduction and low density. However,the noble metal aerogels with outstanding solderability were rarely studied. This work has successfully synthesized an aerogel derived from silver nanowires(AgNWs) using a liquid phase reduction method. It is found that the noble metal aerogels can be made into diverse aerogel preformed soldering sheets. The influence of bonding temperature(150-300 ℃), time(2-20 min), and pressure(5-20 MPa) on the joint strength of the AgNWs aerogel affixed to electroless nickel/silver copper plates were investigated. Additionally, the AgNWs aerogel displays almost the same shear strength for substrates of various sizes. In a word, this study presents a flux-free, high-strength, and adaptable soldering structural material.
基金partly supported by Showa Denko Co. Ltd, Grant-in-Aid for Scientific Research (Kaken S, 24226017)COI Stream Projectfinancial support from China Scholarship Council
文摘Transparent electrode based on silver nanowires(Ag NWs) emerges as an outstanding alternative of indium tin oxide film especially for flexible electronics. However, the conductivity of Ag NWs transparent electrode is still dramatically limited by the contact resistance between nanowires at high transmittance. Polyvinylpyrrolidone(PVP) layer adsorbed on the nanowire surface acts as an electrically insulating barrier at wire–wire junctions, and some devastating post-treatment methods are proposed to reduce or eliminate PVP layer, which usually limit the application of the substrates susceptible to heat or pressure and burden the fabrication with high-cost, time-consuming, or inefficient processes. In this work, a simple and rapid pre-treatment washing method was proposed to reduce the thickness of PVP layer from 13.19 to0.96 nm and improve the contact between wires. Ag NW electrodes with sheet resistances of 15.6 and 204 X sq-1have been achieved at transmittances of 90 and 97.5 %, respectively. This method avoided any post-treatments and popularized the application of high-performance Ag NW transparent electrode on more substrates. The improved Ag NWs were successfully employed in a capacitive pressure sensor with high transparency, sensitivity, and reproducibility.
基金This research was financially supported by the National Key R&D Program of China(2017YFB1104300)the National Science Foundation(CMMI 1825608)Nebraska Center for Energy Sciences Research,and National Natural Science Foundation of China(61774067).The authors would like to thank Professor Stephen Ducharme for valuable discussions regarding the electrical conductivity analysis of this work and Joel Brehm for figure improvement.
文摘Three-dimensional(3D)electrically conductive micro/nanostructures are now a key component in a broad range of research and industry fields.In this work,a novel method is developed to realize metallic 3D micro/nanostructures with silver-thiol-acrylate composites via two-photon polymerization followed by femtosecond laser nanojoining.Complex 3D micro/nanoscale conductive structures have been successfully fabricated with∼200 nm resolution.The loading of silver nanowires(AgNWs)and joining of junctions successfully enhance the electrical conductivity of the composites from insulating to 92.9 Sm^−1 at room temperature.Moreover,for the first time,a reversible switching to a higher conductivity is observed,up to∼10^5Sm^−1 at 523 K.The temperature-dependent conductivity of the composite is analyzed following the variable range hopping and thermal activation models.The nanomaterial assembly and joining method demonstrated in this study pave a way towards a wide range of device applications,including 3D electronics,sensors,memristors,micro/nanoelectromechanical systems,and biomedical devices,etc.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 90201036, 60125103, 60228005 and 90206028）.
文摘Large-scale silver nanowires with controlled aspect ratio were synthesized via reducing silver nitrate with 1, 2- propanediol in the presence of poly （vinyl pyrrolidone） （PVP）. Scanning electron microscopy, transmission electron microscopy and x-ray powder diffraction were employed to characterize these silver nanowires. The diameter of the silver nanowires can be readily controlled in the range of 100 to 400 nm by varying the experimental conditions. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results show that there exists no chemical bond between the silver and the nitrogen atoms. The interaction between PVP and silver nanowires is mainly through the oxygen atom in the carbonyl group.
基金supported by National Natural Science Foundation of China (51876112 & 51590901)Shanghai Municipal Natural Science Foundation (Grant No. 17ZR1411000)+1 种基金Shu Guang project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation (15SG52)Qingdao University of Science and Technology (51676103)
文摘Two kinds of silver nanowires(100 nm in diameter, 20 μm and 100 μm in length) are prepared. The thermo-physical characteristics, viscosity, and photothermal conversion performance of the silver nanowires(AgNWs)contained ethylene glycol nanofluids are investigated in detail. It is found that thermal conductivity of 100 μm AgNWs contained nanofluids is higher than that of 20 μm AgNWs with the same diameters of 100 nm. Viscosity test shows that the nanofluid is a Newtonian fluid, and the longer silver nanowires, the greater viscosity. In addition, photothermal conversion efficiency of silver nanowires contained nanofluid is studied. We can observe that the 100 μm AgNWs contained nanofluid has a higher photothermal conversion efficiency than that containing 20 μm AgNWs. Moreover, we find that there is a certain correlation between heat transfer and photothermal conversion of nanofluid. It demonstrates that the high heat transfer property of nanofluid will benefit for its photothermal conversion efficiency and the mechanism is proposed. This work provides a new idea to improve photothermal conversion efficiency. We can choose materials with high thermal conductivity and strong light absorption ability to enhance the photothermal conversion performance of nanofluids.
文摘The change of conductivity and transparency of silver nanowire （AgNW） films by adding silver nano-particles （AgNPs） onto their surface is studied. The results show that the conductivity of the AgNW film is greatly improved with its sheet resistance reduced about 78. 7% to 51.9Ω/sq, and there is no obvious reduction of the transmittance. Further studies show that there is a self-assembling process pushing the AgNPs to concentrate at the intersecting points between AgNWs to weld them, which would reduce the intersection resistance between the AgNWs. This self-assembling behavior is led by the surface interactivities among the dispersing liquid of AgNPs, the surface of the substrate and AgNWs when the dispersing liquid is drying.
基金supported by the National Natural Science Foundation of China(Grant Nos.11374012,11134013,11227407,and 61210017)the Ministry of Science and Technology of China(Grant No.2012YQ12006005)the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No.KJCX2-EWW04)
文摘Using propagating surface plasmons （SPs） on a silver nanowire （NW）, we demonstrate that a focused laser light at the end of the silver NW can excite a single quantum dot （QD） microns away from the excitation spot. The QD-NW interaction allows the excited QD convert part of its energy into propagating SPs, which then can be detected at remote sites. Simultaneous multi-QD remote excitation and remote detection can also be realized. Furthermore, the tight confinement of the propagating SPs around the NW surface enables the selective excitation of QDs very close in space, which cannot be realized under the conventional excitation condition. This remote excitation and remote detection approach may find applications in optical imaging and the sensing of chemical and biological systems.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0400603)the National Natural Science Foundation of China(Grant No.61335004)
文摘Silver nanowire（AgNW） networks have been demonstrated to exhibit superior transparent and conductive performance over that of indium-doped tin oxide（ITO） and have been proposed to replace ITO, which is currently widely used in optoelectronic devices despite the scarcity of indium on Earth. In this paper, the current spreading and enhanced transmittance induced by AgNWs, which are two important factors influencing the light output power, were analyzed. The enhanced transmittance was studied by finite-difference time-domain simulation and verified by cathodoluminescence measurements.The enhancement ratio of the light output power decreased as the Ga P layer thickness increased, with enhancement ratio values of 79%, 52%, and 15% for Ga P layer thicknesses of 0.5 μm, 1 μm, and 8 μm, respectively, when an AgNW network was included in Al Ga In P light-emitting diodes. This was because of the decreased current distribution tunability of the AgNW network with the increase of the Ga P layer thickness. The large enhancement of the light output power was caused by the AgNWs increasing carrier spread out of the electrode and the enhanced transmittance induced by the plasmonic AgNWs. Further decreasing the sheet resistance of AgNW networks could raise their light output power enhancement ratio.
文摘The effect of an external magnetic field on the preparation of silver nanowires was studied. The silver nanowires were synthesized using solid electrolyte RbAg4I5 thin films by applying both a direct current （DC） electric field and a magnetic field. The RbAg4I5 thin films, which were prepared by deposition at room temperature and atmospheric pressure on a NaCI substrate, were used for the transfer of Ag^＋ ions between two Ag electrodes during the preparation process. When only the DC electric field is applied, the silver ions migrate toward the cathode. On the edge of the silver film at the cathode the Ag^＋ ions congregate to form aligned nanowires. If the magnetic field is also applied perpendicular to the DC electric field, the morphology of the nanowires can be controlled by rotating the sample in the magnetic field. Experimental results show that the growth of the silver nanowires is determined by the Ag^＋ ionic flux.
基金Supported by the International S&T Cooperation Program of China under Grant No 2015DFH60240the Ningbo Municipal Science and Technology Innovative Research Team under Grant No 2016B10005+1 种基金the Zhejiang Provincial Natural Science Foundation of China under Grant No LY15B050003the Ningbo Natural Science Foundation under Grant No 2016A610281
文摘High-haze flexible transparent conductive polymethyl methacrylate （PMMA） films embedded with silver nanowires （AgNWs） are fabricated by a low-cost and simple process. The volatilization rate of the solvent in PMMA solution affects the surface microstructures and morphologies, which results in different haze factors of the composite films. The areal mass density of AgNW shows a significant influence on the optical and electrical properties of composite films. The AgNW/PMMA transparent conductive films with the sheet resistance of 5.5Ω sq ^-1 exhibit an excellent performance with a high haze factor of 81.0% at 550？nm.
基金supported by the National Natural Science Foundation of China(Nos.22171066 and 21922104)the Fundamental Research Funds for the Central Universities(Nos.JZ2023YQTD0074 and JZ2021HGPA0064)the University Synergy Innovation Program of Anhui Province(No.GXXT-2019-028).
文摘Conductive fibers(CFs)with features of high conductivity,stretchability,self-healability,and electromechanical stability are key components of the increasingly popular wearable electronics.However,since the lack of structural design of conductive network and interfacial interaction between soft polymer and conductive additives,it is still hard to enable CFs to meet above requirements.Here,we describe a facial drawing method from a hydrogel reservoir which is remolded into ultrathin and stretchable CFs with excellent multi-responsive self-healability.The hydrogel reservoir was fabricated in synergy of an ice-templating method and in situ polymerization using the assembled framework as a crosslinker.Relying on the effective fabrication mechanism,the diameter of CFs could be well-tuned from 90 to 400μm by adjusting the dipping depth of the glass rod,accompanied with conductivity increased from 0.75 to 2.5 S/m.Since the hierarchical network structure was well maintained in the CFs,professional performances have been proved on the stretchability and electromechanical stability.The presence of massive hydrogen bonding and Ag–S bond enabled the CFs with excellent self-healability under the conditions of contact,electric field,and near infrared light,respectively.Excitingly,the CFs with high sensing property could be integrated into an advanced textile sensor through an effective healing-induced integration strategy,demonstrating its great potentials as superior two-dimensional(2D)electronic skins.
基金supported by the National Natural Science Foundation of China(nos.21988102 and 22305026)the China Postdoctoral Science Foundation(2019M650433).
文摘Silver nanowire(AgNW)networks hold great promises as next-generation flex-ible transparent electrodes(FTEs)for high-performance flexible optoelectronic devices.However,achieving large-area flexible AgNW network electrodes with low sheet resistance,high optical transmittance,and a smooth surface remains a grand challenge.Here,we report a straightforward and cost-effective roll-to-roll method that includes interface assembly/wetting-induced climbing transfer,nanowelding,and washing processess to fabricate flexible ordered lay-ered AgNW electrodes with high network uniformity.By manipulating the stacking number of the interfacially assembled AgNW monolayer,we can pre-cisely tailor and balance the transparency and the conductivity of the elec-trodes,achieving an exceptional Figure of Merit(FoM)value of 862.Moreover,the ordered layered structure enhances surface smoothness,compared with randomly arranged structures.To highlight the potential of these ordered lay-ered AgNW network electrodes in flexible optoelectronic devices,we success-fully employ them as highly sensitive strain sensors,large-area flexible touch screens,and flexible smart windows.Overall,this work represents a substantial advance toward high-performance FTEs over large areas,opening up exciting opportunities for the development of advanced optoelectronic devices.
文摘Understanding the structural stability of nanomaterials such as nanowires is imperative for their practical applications.Here,using single-shot ultrafast transmission electron microscopy,we captured the Plateau-Rayleigh instability behavior of silver nanowires decomposing into silver nanoparticles upon laser irradiation on nanosecond time scales.We found that this dynamic process can be accelerated by a factor of 10 through increasing the peak laser fluence from 6.03 to 14.60 mJ/cm^(2).Moreover,by comparing the laser fluence required to initiate the Plateau-Rayleigh instability in silver nanowires on carbon and Formvar membranes,it was found that the main driving force for the Plateau-Rayleigh instability in this study was substrate heating.Finite element analysis and molecular dynamics simulations are also applied to estimate the temperature jump of the nanowires and atomistic behavior,respectively.In addition,the complex motions of silver nanowires under laser irradiation were systematically investigated by combining the results of ultrafast transmission electron microscopy with scanning electron microscopy characterizations and were determined to be related to nanowire-membrane interactions or pre-existing stresses on the nanowires,which in turn demonstrated the potential of ultrafast transmission electron microscopy for the characterization of nanomaterials and devices under extreme conditions.
基金financially supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(nos.NRF-2020R1A5A1018153,NRF-2021R1A2C2010530,and 2022M3J1A106422611)The authors acknowledge King Saud University,Riyadh,Saudi Arabia,for funding this work through Researchers Supporting Project number(RSP2023R30).
文摘Traditional Korean Hanji paper and cotton fabric were introduced as flexible substrates in the fabrication of graphene-coated heaters.Silver nanowires and PEDOT:PSS were added to increase the electrical conductivity of the heaters,thereby enhancing their heating performance.The optimal concentrations of silver nanowires and PEDOT:PSS with respect to that of graphene were identified.These active materials were deposited on flexible Hanji/cotton and non-flexible alumina substrates using supersonic spraying.The proposed Hanji-and cotton-based heaters were light,wearable,stretchable,skin-friendly,and biodegradable.The unyielding alumina-based heater exhibited the highest heating temperature of 275°C at 13 V.Wearable heater bendability and stretchability were tested considering multiple bending and stretching cycles.Moreover,water boiling and fabric drying were successfully performed using the alumina-based heater.The supersonic spraying deposition technique was used to produce writable and patternable heaters.
基金supported by the Key-Area Research and Development Program of Guangdong Province(No.2019B010934001)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(No.19lgzd12)the Scientific and Technological Projection of Guangdong Province(No.2020B1212060030).
文摘Stretchable transparent electrode(STE)plays a key role in numerous emerging applications as an indispensable component for future stretchable devices.The embedded STE,as a promising candidate,possesses balanced performances and facile preparation procedures.However,it still suffers from the defects of conductive materials caused by the transferring,which results in the irreversible failure of devices.In this work,a patternable silver nanowire(AgNW)STE was fabricated by a plasma-enhanced cryo-transferring(PEC-transferring)process.Owing to the plasma-induced sintering,the AgNW network obtained remarkable improvement in robustness,which ensured the intact network after transferring and thus led to superior tensile electrical properties of the STE.Furthermore,serpentine patterns were utilized to optimize the tensile electrical properties of the STE,which achieved a figure of merit of 292.8 and 150%resistance changing under 50%strain.As a practical application,a 4×3 array of the mutual-capacitive type stretchable touch sensors was demonstrated for future touch sensors in stretchable devices.The PEC-transferring process opened a new avenue for patternable embedded STEs and exhibited its high potential in wearable electronics and the Internet of Thing devices.
文摘Silver nanowires （AgNWs） surrounded by insulating poly（vinylpyrrolidone） have been synthesized by a polyol process and employed as transparent electrodes. The AgNW transparent electrodes can be fabricated by heattreatment at about 200 ℃ which forms connecting junctions between AgNWs. Such a heating process is, however, one of the drawbacks of the fabrication of AgNW electrodes on heat-sensitive substrates. Here it has been demonstrated that the electrical conductivity of AgNW electrodes can be improved by mechanical pressing at 25 MPa for 5 s at room temperature. This simple process results in a low sheet resistance of 8.6 Ω/square and a transparency of 80.0%, equivalent to the properties of the AgNW electrodes heated at 200 ℃. This technique makes it possible to fabricate AgNW transparent electrodes on heat-sensitive substrates. The AgNW electrodes on poly（ethylene terephthalate） films exhibited high stability of their electrical conductivities against the repeated bending test. In addition, the surface roughness of the pressed AgNW electrodes is one-third of that of the heat-treated electrode because the AgNW junctions are mechanically compressed. As a result, an organic solar cell fabricated on the pressed AgNW electrodes exhibited a power conversion as much as those fabricated on indium tin oxide electrodes. These findings enable continuous roll-to-roll processing at room temperature, resulting in relatively simple, inexpensive, and scalable processing that is suitable for forthcoming technologies such as organic solar cells, flexible displays, and touch screens.
文摘Transparent electrodes made of silver nanowires （AgNWs） exhibit higher flexibility when compared to those made of tin doped indium oxide （ITO） and are expected to be applied in plastic electronics. However, these transparent electrodes composed of AgNWs show high haze because the wires cause strong light scattering in the visible range. Reduction of the wire diameter has been proposed as a way to weaken light scattering, although there have seldom been any studies focusing on the haze because of the difficulty involved in controlling the wire diameter. In this report, we show that the haze can be easily reduced by increasing the length of AgNWs with a large diameter. Ultra-long （u-long） AgNWs with lengths in the range of 20-100 μm and a maximum length of 230 μm have been successfully synthesized by adjusting the reaction temperature and the stirring speed of a one-step polyol process. Compared to typical AgNWs （with diameter and length of 70 nm and 10 μm, respectively） and ITO, a transparent electrode consisting of u-long AgNWs 91 nm in diameter demonstrated a low haze of 3.4%-1.6% and a low sheet resistance of 24-109 Ω/sq. at a transmittance of 94%-97%. Even when fabricated at room temperature without any post-treatment, the electrodes composed of u-long AgNWs achieved a sheet resistance of 19 Ω/sq, at a transmittance of 80%, which is six orders of magnitude lower than that of typical AgNWs.
文摘Contemporary nanostructured transparent electrodes for use in solar cells require high transmittance and high conductivity, dictating nanostructures with high aspect ratios. Optical haze is an equally important yet unstudied parameter in transparent electrodes for solar cells that is also determined by the geometry of the nanostructures that compose the electrode. In this work, the effect of the silver nanowire diameter on the optical haze values in the visible spectrum was investigated using films composed of wires with either small diameters （N60 nm） or large diameters （~150 nm）. Finite difference time domain （FDTD） simulations and experimental transmittance data confirm that smaller diameter nanowires form higher performing transparent conducting electrode （TCE） films according to the current figure of merit. While maintaining near constant transmittance and conductivity for each film, however, it was observed experimentally that films composed of silver nanowires with larger diameters have a higher haze factor than films with smaller diameters. This confirms the FDTD simulations of the haze factor for single nanowires with similarly large and small diameters. This is the first record of haze properties for Ag NWs that have been simulated or experimentally measured, and also the first evidence that the current figure of merit for TCEs is insufficient to evaluate their performance in solar cell devices.
