Electroless Plating of Thin Silver Films on Porous Al_2O_3 Substrate and the Study of Deposition Kinetics

A novel concept has been developed to coat the inner pore surfaces of reticulated alumina with a thin silver film by an electroless-plating method. As a result of coating, the porous alumina sample exhibits a sharp transition from insulating to conducting due to a thin silver layer on the inner pore surfaces. Systematic studies have been carried out to investigate the coating kinetics by employment of scanning electron microscope （SEM）, X-ray diffraction （XRD）, and computer simulation. Both coating procedures and effects of processing parameters on the quality of films are reported. Also, this paper presents the film bonding strength to the substrate, effects of sintering, and conduction mechanism of coated composite. The fundamental silver electroless-plating mechanism has been identified based on computer modeling. The simulation results indicate an excellent agreement between the silver deposition behavior and the physical model applied.

Optical performance of ultra-thin silver films under the attenuated total reflection mode

Ultra-thin silver films were deposited by thermal evaporation, and the dielectric functions of samples were simulated using Drude-Lorentz oscillators. When s-polarized incident light from the BK7 glass into thin silver film at 45°angle using attenuated total reflection （ATR） mode, we experimental observed that the reflection reach a minimum of 1.87% at 520 nm for thickness of d--6.3 nm silver film, and it reach a minimum of 10.1% at 500 nm for thickness of d--4.1 nm. Moreover, we simulated the absorption changes with incident angles at 520 nm for both p-polarized （TM wave） and s-polarized （TE wave） light using transfer matrix theory, and calculated the electric field distributions. The absorption as a function of incident angles of TM wave and TE wave showed different characteristics under ATR mode, TE wave reached the maximum absorption around the critical angle θc-41.1°, while TM wave reached the minimum absorption.

Evolution of the structural and optical properties of silver oxide films with different stoichiometries deposited by direct-current magnetron reactive sputtering

Nitrogen doping of silver oxide （AgxO） film is necessary for its application in transparent conductive film and diodes because intrinsic AgxO film is a p-type semiconductor with poor conductivity. In this work, a series of AgxO films is deposited on glass substrates by direct-current magnetron reactive sputtering at different flow ratios （FRs） of nitrogen to 02. Evolutions of the structure, the refiectivity, and the transmissivity of the film are studied by X-ray diffractometry and sphectrophotometry, respectively. The specular transmissivity and the specular refiectivity of the film decreasing with FR increasing can be attributed to the evolution of the phase structure of the film. The nitrogen does not play the role of an acceptor dopant in the film deposition.

Fabrication of High-Haze Flexible Transparent Conductive PMMA Films Embedded with Silver Nanowires

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.

Surface Enhanced Raman Scattering on Self-assembled Nano Silver Film Prepared by Electrolysis Method

We demonstrate surface enhanced Raman scattering （SERS） detection of self-assembled nano silver film using a low-cost electrolysis strategy at a proper voltage and silver nitrate concentration in electrolyte. The concentration dependence of SERS from crystal violet （CV） molecules adsorbed to silver film was systematically studied. Importantly, the SERS surface enhancement factor of such nano silver film was 603, which was measured by a portable Raman spectrometer. The minimum concentration of detectable CV molecules can be as low as 10^-11 mol/L. The nano silver film prepared by this electrolysis method is an active, stable, cost-effective, and reusable SERS substrate.

The Effect of Laser Irradiation on Surface Enhanced Raman Scattering for Silver Film

The laser irradiation effect on the SERS intensity for Ag film is discussed using crystal violet (CV) as a probe. The thickness of silver film,the etching time of the glass slide by gaseous hydrogen fluoride, and the laser irradiation time for different amounts of CV on silver films were investigated. The laser burn out model was proposed to explain the dependence of the SERS intensity of CV on the laser irradiation time.

Fabrication Silver Film inside Silica Capillary

To study hollow waveguides for CO 2 laser transmission,a liquid-phase depositi on technique is applied to form a silver film inside silica capillary based on t he method of silver mirror reaction.Using this fabrication method,the optimum co mbination of different parameters is gained and hollow waveguides have been made successfully with a bore size of 1mm and a guide with length of as long as 2m o n self-producing apparatus.To meet quality silver film,a relative high temperat ure,low flowing speed and long time are adopted on the basis of low reactant con centration.The maximum transmission efficiency of hollow-core fiber without die lectric coating can be up to 85 percent and loss can be low to 0.5dB/m,maximum o utput power is 53W for stable 20mintues.

Improvement of the Conductivity of Silver Nanowire Film by Adding Silver Nano-Particles

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.

A STUDY ON VOLTAMMETRIC BEHAVIOR OF INDIGO CARMINE AND ITS MIXTURE WITH AMARANTH AT MERCURY FILM ELECTRODE ON SILVER SUBSTRATE

The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml. The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.

Flexible carbon nanotube-enriched silver electrode films with high electrical conductivity and reliability prepared by facile screen printing

Flexible electrode films play critical and fundamental roles in the successful development of flexible electronic devices. In this study, carbon nanotubes（CNTs） were implanted into silver（Ag） ink to enhance the electrical conductivity and the reliability of the printed Ag electrode films. The fabricated carbon nanotubes-enriched silver（Ag-CNTs） electrode films were printed on the polyimide substrates by a facile screen printing method and sintered at a relatively low temperature. The resistivity of Ag-CNTs films was decreased by 62.27% compared with the pure Ag film. Additionally, the Ag-CNTs films exhibited excellent flexibility under a bending radius of 4 mm（strain ε = 2.09%） over 1000 cycles. Furthermore, the Ag-CNTs film displayed unchangeable electrical conductivity together with a strong adhesion after an accelerated aging test with 500 thermal shock cycles. These improvements were attributed to the AgCNTs interconnected network structure, which can provide electronic transmission channels and prevent cracks from initiating and propagating.

Magnetoelectrochemical Chirality in Ag E lectrod e position

Chiral behaviors of magnetoelectrodeposited Ag film electrodes were investigated for the electrochemical reactions of glucose and cysteine. The Ag films were electrodeposited under a magnetic field of 2 T perpendicular to the electrode surface at various potentials 0f-0.06-0.4 V （vs Ag I Ag＋）. The current-time curves during the electrodeposition and the surface morphology of the films implied that the film growth was considerably affected by the micro-MHD （magnetohydrodynamic） effect. Such Ag films were employed as an electrode, and voltammograms of glucose and cysteine were examined. Chiral behavior was clearly observed as current difference between the enantiomers on the film electrodes prepared at electrodeposition potentials less than -0.1 V. Such electrochemical chirality disappeared after the oxidation and reduction of the surface monolayer, and this fact indicates that the chiral sites must be just on the film surface.

Fabrication of Flexible Transparent Conductive Films with Silver Nanowire by Vacuum Filtration and PET Mold Transfer

The flexible transparent conductive films （FrCFs） of silver nanowire-polyethylene terephthalate （AgNW- PET） were prepared by a facile method including vacuum filtration and mold transferring. The effect of silver nanowire weight density on the optical and electrical properties of films, as well as the electrical percolation was investigated. The obtained typical AgNW-PET film exhibited high figure of merit of 31.3 × 10^-3 Ω^-1 with low sheet resistance of 4.95 D sq^-1 and high transparency at 550 nm of 83.0% （excluding PET substrate）. The resulting FTCFs based on PET substrate with high transmittance and low sheet resistance have a great potential in the application of high-performance flexible electronics and photovoltaic devices.

Measurement and analysis of the surface roughness of Ag film used in plasmonic lithography

The silver（Ag）/photoresist（PR）/Ag structure, widely used in plasmonic photolithography, is fabricated on silicon substrate. The surface roughness of the top Ag film is measured and analyzed systematically. In particular, combined with template stripping technology, the lower side of the top Ag film is imaged by an atomic force microscope. The topographies show that the lower side surface is rougher than the initial surface of the subjacent PR film, which is mainly attributable to the deformation caused by particle collisions during the deposition of the Ag film. Additionally, further measurements show that the Ag film deposited on the PR exhibits a flatter upper side morphology than that directly deposited on the silicon substrate. This is explained by the different growth modes of Ag films on different substrates. This work will be beneficial to morphology analysis and performance evaluation for the films in optical and plasmonic devices.

Multifunctional silver film with superhydrophobic and antibacterial properties

Material properties are strongly dependent on material structure. The large diversity and complexity of material structures provide significant opportunities to improve the properties of the materials, expanding their applications. Here, we discuss the fabrication of a multifunctional silver film prepared by controlling the nucleation and growth of silver particles. Silver films with high hydrophobicity and antibacterial activity were fabricated by adopting an electrochemical approach. The dependence of the hydrophobic and antibacterial properties on the size and shape of the silver particles was first investigated. Small-sized silver particles exhibited a high antibacterial rate, while a porous silver film composed of dendritic particles showed a significant hydrophobic activity. By regulating the reaction time, current density, and silver salt concentration, a silver film with a contact angle of 150.9° and an antibacterial rate of 54.7% was synthesized. This study demonstrates that finding a compromise between different material structures is a suitable wav to fabricate multifunctional devices.

Floating silver film： A flexible surface-enhanced Raman spectroscopy substrate for direct liquid phase detection at gas-liquid interfaces

In recent years, surface-enhanced Raman spectroscopy （SERS） has developed rapidly and is used for the detection of molecules and biomolecules in liquids. However, few studies have focused on SERS using a water surface as the substrate. A floating metal film on water is desirable for an enhanced SERS performance. In this work, silver nanopartides （Ag NPs） encased in poly（vinylpyrrolidone） films （Ag-PVP films） were synthesized on the surface of an aqueous solution by room temperature electron reduction. A floating silver film on a water surface was thereby achieved and is reported for the first time. The synthesized Ag-PVP film is an excellent flexible substrate for SERS and has other potential appli- cations. Using the floating silver film as a flexible SERS substrate, 10-11 M of 4-aminothiophenol, 10^-6 M of riboflavin, 10^-9 M of 4-mercaptobenzoic acid, 10^-7 M of 4-mercaptophenol, and 10^-7 M of 4-aminobenzoic acid are identified, demonstrating potential use for the floating substrate in the liquid-phase detection of molecules.

Conductive Film with Flexible and Stretchable Capability for Sensor Application and Stealth Information Transmission

Flexible and wearable strain sensors for human-computer interaction,health monitoring,and soft robotics have drawn widespread attention to promising applications in the next generation of artificial intelligence devices.However,conventional semiconductor sensors are difficult to meet the requirements of flexibility and stretchability.Here,we reported a kind of novel and simple sensor based on layer-by-layer(LBL)method.Carbon nanotubes(CNTs)layer provides high ductility and stability in the process of tension sensing,while silver layer provides low initial resistance and fast reflecting in the process of tension sensing.LBL method ensures the uniformity of the conductive layer.The sensor has superior sheet resistance of 9.44Ω/sq.,high elongation at break of 104%.For sensing capability,the sensor has wide reflecting range of 60%,high gauge factor(GF)of 1000 up to 60%strain,fast reflecting time of 165 ms.Excellent reliability and stability have also been verified.It is also worth mentioning that the entire process does not require any expensive equipments,complicated processes or harsh experimental conditions.The above features provide an idea for large-scale application of flexible stretchable sensors.

Multifunctional semitransparent organic solar cells with excellent infrared photon rejection

Semitransparent organic solar cells(ST-OSCs)have the potentials to open promising applications that differ from those of conventional inorganic ones,such as see-through power windows with both energy generation and heat insulation functions.However,to achieve so,there remain significant challenges,especially for balancing critical parameters,such as power conversion efficiency(PCE),average visible transparency(AVT)and low energy infrared photon radiation rejection(IRR)to realize the full potentials of ST-OSCs.Herein,we demonstrate the new design of ST-OSCs through the rational integration of organic materials,transparent electrode and infrared photon reflector in one device.With the assistance of optical simulation,new ST-OSCs with precise layout exhibit state-of-art performance,with near 30%AVT and PCE of 7.3%,as well as an excellent IRR of over 93%(780-2500 nm),representing one of best multifunctional ST-OSCs with promising perspective for window application.