scholarly journals Graphene/Silver Nanowires/Graphene Sandwich Composite for Stretchable Transparent Electrodes and Its Fracture Mechanism

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 512
Author(s):  
Chi-Hsien Huang ◽  
Hong-Cing Wu ◽  
Bo-Feng Chen ◽  
Yen-Cheng Li
Keyword(s):  
Sandwich Structure ◽  
Silver Nanowires ◽  
High Surface ◽  
Chemical Vapor ◽  
Electrical Performance ◽  
Sandwich Composite ◽  
Transparent Electrodes ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Conductivity Loss

Polycrystalline graphene grown by chemical vapor deposition (CVD) is characterized by line defects and disruptions at the grain boundaries and nucleation sites. This adversely affects the stretchability and conductivity of graphene, which limits its applications in the field of flexible, stretchable, and transparent electrodes. We demonstrate a composite electrode comprised of a graphene/silver nanowires (AgNWs)/graphene sandwich structure on a polydimethylsiloxane substrate to overcome this limitation. The sandwich structure exhibits high transparency (>90%) and excellent conductivity improvement of the graphene layers. The use of AgNWs significantly suppresses the conductivity loss resulting from stretching. The mechanism of the suppression of the conductivity loss was investigated using scanning electron microscopy, atomic force microscopy, and lateral force microscopy. The results suggest that the high surface friction of the sandwich structure causes a sliding effect between the graphene layers would produce low crack or hole formation to maintain the conductivity. In addition to acting as conductive layers, the top and bottom graphene layers can also protect the AgNWs from oxidation, thereby enabling maintenance of the electrical performance of the electrodes over a prolonged period. We also confirmed the applicability of the sandwich structure electrode to the human body, such as on the wrist, finger, and elbow.

Fundamental Study on Diamond Spherical Shell Film for Polishing of Concave Spherical Surface

2008 ◽  
Vol 375-376 ◽  
pp. 380-384
Author(s):  
Duo Sheng Li ◽  
Dun Wen Zuo ◽  
Rong Fa Chen ◽  
Yu Li Sun ◽  
Bing Kun Xiang ◽  
...  
Keyword(s):  
Spherical Shell ◽  
Spherical Surface ◽  
High Surface ◽  
Chemical Vapor ◽  
High Hardness ◽  
Internal Quality ◽  
Curvature Radius ◽  
Fundamental Study ◽  
Force Microscopy ◽  
Spherical Surfaces

In this paper, a new polishing technique was proposed to polish concave spherical surface by diamond spherical shell deposited by DC-Plasma Jet CVD(chemical vapor deposition), and preparation was studied from both experiment and theory. The deposited films were investigated by some techniques including: scanning electron microscopy (SEM), atom force microscopy (AFM), Raman spectroscopy, and roughness-profile-meter, which were used to analyze surface phase, microstructure, internal quality and surface roughness. The results show that the deposited diamond spherical shell film has some remarkable properties, such as high surface density, high hardness. Compared to traditional polishing techniques, it will have some potential advantages as convenient, flexible, efficient and precious. To adjust some important parameters as methane concentration, depositing time, and it can deposit the different size grain diamond spherical shell films, which are used to polish different precision degree concave spherical surfaces. Meantime, to change curvature of diamond spherical shell, it can adapt to polish various curvature radius concave spherical surfaces.

scholarly journals Synthesis and Characterization of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite as Transparent Conductive Film with Enhanced Stiffness

2020 ◽  
Vol 10 (14) ◽  
pp. 4802
Author(s):  
Chuanrui Guo ◽  
Yanxiao Li ◽  
Yanping Zhu ◽  
Chenglin Wu ◽  
Genda Chen
Keyword(s):  
Electrical Conductivity ◽  
Chemical Vapor ◽  
Optical Transmittance ◽  
Silver Nanowire ◽  
Sandwich Composite ◽  
Graphene Layers ◽  
Behavior Study ◽  
Transmission Electron ◽  
Grown Graphene ◽  
Film Stiffness

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis and transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite has been proposed to overcome these drawbacks significantly as the AgNW network can provide extra connections on graphene layers to enhance the stiffness and electrical conductivity. However, the existing substrate (polyethylene terephthalate (PET), glass, silicon, and so on) for composite production limits its application and mechanics behavior study. In this work, a vacuum annealing method is proposed and validated to synthesize the free-stand Gr/AgNW/Gr nanocomposite film on transmission electron microscopy (TEM) grids. AgNW average spacing, optical transmittance, and electrical conductivity are characterized and correlated with different AgNW concentrations. Atomic force microscope (AFM) indentation on the free-stand composite indicates that the AgNW network can increase the composite film stiffness by approximately 460% with the AgNW concentration higher than 0.6 mg/mL. Raman spectroscopy shows the existence of a graphene layer and the disturbance of the AgNW network. The proposed method provides a robust way to synthesize free-stand Gr/AgNW/Gr nanocomposite and the characterization results can be utilized to optimize the nanocomposite design for future applications.

scholarly journals Silver Nanowires as Electron Transfer Mediators in Electrochemical Catechol Biosensors

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 899
Author(s):  
Coral Salvo-Comino ◽  
Fernando Martin-Pedrosa ◽  
Cristina Garcia-Cabezon ◽  
Maria Luz Rodriguez-Mendez
Keyword(s):  
Electron Transfer ◽  
Limit Of Detection ◽  
Silver Nanowires ◽  
High Surface ◽  
Volume Ratio ◽  
Homogeneous Distribution ◽  
Electron Mediator ◽  
Force Microscopy ◽  
Voltammetric Detection ◽  
Order Of Magnitude

The integration of nanomaterials as electron mediators in electrochemical biosensors is taking on an essential role. Due to their high surface-to-volume ratio and high conductivity, metallic nanowires are an interesting option. In this paper, silver nanowires (AgNWs) were exploited to design a novel catechol electrochemical biosensor, and the benefits of increasing the aspect ratio of the electron mediator (nanowires vs. nanoparticles) were analyzed. Atomic force microscopy (AFM) studies have shown a homogeneous distribution of the enzyme along the silver nanowires, maximizing the contact surface. The large contact area promotes electron transfer between the enzyme and the electrode surface, resulting in a Limit of Detection (LOD) of 2.7 × 10−6 M for tyrosinase immobilized onto AgNWs (AgNWs-Tyr), which is one order of magnitude lower than the LOD of 3.2 × 10−5 M) obtained using tyrosinase immobilized onto silver nanoparticles (AgNPs-Tyr). The calculated KM constant was 122 mM. The simultaneous use of electrochemistry and AFM has demonstrated a limited electrochemical fouling that facilitates stable and reproducible detection. Finally, the biosensor showed excellent anti-interference characteristics toward the main phenols present in wines including vanillin, pyrogallol, quercetin and catechin. The biosensor was able to successfully detect the presence of catechol in real wine samples. These results make AgNWs promising elements in nanowired biosensors for the sensitive, stable and rapid voltammetric detection of phenols in real applications.

Metal Microstructures in Advanced CMOS Devices

1996 ◽  
Vol 54 ◽  
pp. 358-359
Author(s):  
L. M. Gignac ◽  
K. P. Rodbell
Keyword(s):  
Grain Boundaries ◽  
Semiconductor Device ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Metal Films ◽  
Thin Metal ◽  
Electrical Performance ◽  
Thin Metal Films ◽  
Chemical Vapor Deposited ◽  
Boundary Properties

As advanced semiconductor device features shrink, grain boundaries and interfaces become increasingly more important to the properties of thin metal films. With film thicknesses decreasing to the range of 10 nm and the corresponding features also decreasing to sub-micrometer sizes, interface and grain boundary properties become dominant. In this regime the details of the surfaces and grain boundaries dictate the interactions between film layers and the subsequent electrical properties. Therefore it is necessary to accurately characterize these materials on the proper length scale in order to first understand and then to improve the device effectiveness. In this talk we will examine the importance of microstructural characterization of thin metal films used in semiconductor devices and show how microstructure can influence the electrical performance. Specifically, we will review Co and Ti silicides for silicon contact and gate conductor applications, Ti/TiN liner films used for adhesion and diffusion barriers in chemical vapor deposited (CVD) tungsten vertical wiring (vias) and Ti/AlCu/Ti-TiN films used as planar interconnect metal lines.

12-1: Invited Paper : Stretchable Transparent Electrodes Based on Silver Nanowires

2017 ◽  
Vol 48 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Kwing Tong ◽  
Dustin Chen ◽  
Jiajie Liang ◽  
Qibing Pei
Keyword(s):  
Silver Nanowires ◽  
Transparent Electrodes

scholarly journals Effects of Concentration and Spin Speed on the Optical and Electrical Properties of Silver Nanowire Transparent Electrodes

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2219
Author(s):  
Xiaopeng Li ◽  
Jiayue Zhou ◽  
Dejun Yan ◽  
Yong Peng ◽  
Yong Wang ◽  
...  
Keyword(s):  
Sheet Resistance ◽  
Spin Coating ◽  
Figure Of Merit ◽  
Silver Nanowires ◽  
Solution Concentration ◽  
Ethanol Solution ◽  
Silver Nanowire ◽  
Optical And Electrical Properties ◽  
Transparent Electrodes ◽  
Spin Speed

In this paper, silver nanowires (AgNWs) with a diameter of 40 nm and a length of 45 μm were dispersed into an ethanol solution to prepare AgNW solutions with concentrations of 1, 2, and 3 mg/mL, respectively. The AgNW solutions were then deposited on a glass substrate using spin-coating at 1000, 2000, and 3000 rpm for 45 s, respectively, to prepare transparent electrodes. The results showed that the distribution of AgNWs on the substrate increased in density with the increase in the AgNW solution concentration and the decrease in spin speed. The effect of concentration on the distribution of AgNWs was greater than that of the spin speed. The transmittance of each electrode was between 84.19% and 88.12% at 550 nm, the average sheet resistance was between 20.09 and 358.11 Ω/sq, the highest figure of merit (FoM) was 104.42, and the lowest haze value was 1.48%. The electrode prepared at 1000 rpm with a concentration of 2 mg/mL and that prepared at 3000 rpm with a concentration of 3 mg/mL were very similar in terms of the average sheet resistance, transmittance at 550 nm, FoM, and haze value; thus, these two electrodes could be considered equivalent. The haze value of the electrode was positively correlated with the spin speed at low concentration, but that relationship became inverse as the concentration rose. For the AgNWs used in this experiment with an aspect ratio of 1125, the concentration of the AgNW solution should reach at least 2 mg/mL to ensure that the FoM of the electrode is greater than 35.

Imaging and nanoprobing of graphene layers for interconnects by conductive atomic force microscopy

2015 ◽  
Vol 54 (5S) ◽  
pp. 05EB02 ◽  
Author(s):  
Li Zhang ◽  
Masayuki Katagiri ◽  
Taishi Ishikura ◽  
Makoto Wada ◽  
Hisao Miyazaki ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Conductive Atomic Force Microscopy ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force

Effectiveness and Reliability of Metal Diffusion Barriers for Copper Interconnects

1995 ◽  
Vol 403 ◽  
Author(s):  
G. Bai ◽  
S. Wittenbrock ◽  
V. Ochoa ◽  
R. Villasol ◽  
C. Chiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Diffusion Barriers ◽  
Copper Interconnects ◽  
Time To Failure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

AbstractCu has two advantages over Al for sub-quarter micron interconnect application: (1) higher conductivity and (2) improved electromigration reliability. However, Cu diffuses quickly in SiO2and Si, and must be encapsulated. Polycrystalline films of Physical Vapor Deposition (PVD) Ta, W, Mo, TiN, and Metal-Organo Chemical Vapor Deposition (MOCVD) TiN and Ti-Si-N have been evaluated as Cu diffusion barriers using electrically biased-thermal-stressing tests. Barrier effectiveness of these thin films were correlated with their physical properties from Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Electron Microscopy (SEM), and Auger Electron Spectroscopy (AES) analysis. The barrier failure is dominated by “micro-defects” in the barrier film that serve as easy pathways for Cu diffusion. An ideal barrier system should be free of such micro-defects (e.g., amorphous Ti-Si-N and annealed Ta). The median-time-to-failure (MTTF) of a Ta barrier (30 nm) has been measured at different bias electrical fields and stressing temperatures, and the extrapolated MTTF of such a barrier is > 100 year at an operating condition of 200C and 0.1 MV/cm.

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