Enhancement of Characteristics of Transparent Conductive Electrode on Flexible Substrate by Combination of Solution-Based Oxide and Metallic Layers

2015 ◽  
Vol 15 (10) ◽  
pp. 7997-8003 ◽  
Author(s):  
Sung-Jei Hong ◽  
Yong-Hoon Kim ◽  
Seung-Jae Cha ◽  
Yong-Sung Kim
Keyword(s):  
Thermal Stability ◽  
Sheet Resistance ◽  
Flexible Electronics ◽  
Indium Tin Oxide ◽  
Silver Nanowires ◽  
Flexible Substrate ◽  
Optical Transmittance ◽  
Transparent Conductors ◽  
Transparent Conductor ◽  
Transparent Conductive Electrode

This study investigates solution-processed transparent conductors with hybrid structure consisting of silver nanowires (AgNWs) and indium-tin-oxide nanoparticles (ITO-NPs) layers fabricated on polymeric flexible polyethylene terephthalate (PET) substrate. The transparent conductors had stacked structures of AgNWs/ITO-NPs on 125-μm-thick PET and ITO-NPs/AgNWs/ITO-NPs on 125-μm-thick PET, 188-μm-thick PET, or 700-μm-thick glass substrate, respectively. Successful integrations were possible on the substrates without any deformation or distortion. Sheet resistance of the triplelayered transparent conductor samples exhibits low values ranging from 22.41 Ω/□ to 22.99 Ω/□. Also, their optical transmittance exhibits high values ranging from 83.78 to 87.29% at 550 nm. The triple-layered transparent conductor showed a good thermal stability in terms of sheet resistance and optical transmittance against the high-temperature environment up to 250 °C. All the double and triple-layered transparent conductors fabricated on PET and glass substrates are so stable against the accelerated thermal aging from 110 °C to 130 °C, that ΔR/R0 and ΔT550/T0550 values exhibit less than 0.068 and 0.049, respectively. Furthermore, the layers are so flexible that ΔR/R0 of the layers on PET substrates is lower than 0.1 even at 4.0-mm bending. Especially, triple-layered transparent conductor on 125-μm-thick PET substrates exhibits ΔR/R0 value of 0.042 even at 4.0 mm bending. Thus, it can be concluded that the hybrid structures have the advantage of both thermal stability and flexibility for electrical and optical properties of transparent conductive electrode; which makes them highly applicable in flexible electronics.

scholarly journals Copercolating Networks: An Approach for Realizing High-Performance Transparent Conductors using Multicomponent Nanostructured Networks

Nanophotonics ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 180-195 ◽  
Author(s):  
Suprem R. Das ◽  
Sajia Sadeque ◽  
Changwook Jeong ◽  
Ruiyi Chen ◽  
Muhammad A. Alam ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Indium Tin Oxide ◽  
High Performance ◽  
Silver Nanowires ◽  
Optical Transmittance ◽  
Single Component ◽  
Transparent Conductors ◽  
Hybrid Networks ◽  
Gold Nanowires ◽  
Metallic Nanowire Networks

Abstract Although transparent conductive oxides such as indium tin oxide (ITO) are widely employed as transparent conducting electrodes (TCEs) for applications such as touch screens and displays, new nanostructured TCEs are of interest for future applications, including emerging transparent and flexible electronics. A number of twodimensional networks of nanostructured elements have been reported, including metallic nanowire networks consisting of silver nanowires, metallic carbon nanotubes (m-CNTs), copper nanowires or gold nanowires, and metallic mesh structures. In these single-component systems, it has generally been difficult to achieve sheet resistances that are comparable to ITO at a given broadband optical transparency. A relatively new third category of TCEs consisting of networks of 1D-1D and 1D-2D nanocomposites (such as silver nanowires and CNTs, silver nanowires and polycrystalline graphene, silver nanowires and reduced graphene oxide) have demonstrated TCE performance comparable to, or better than, ITO. In such hybrid networks, copercolation between the two components can lead to relatively low sheet resistances at nanowire densities corresponding to high optical transmittance. This review provides an overview of reported hybrid networks, including a comparison of the performance regimes achievable with those of ITO and single-component nanostructured networks. The performance is compared to that expected from bulk thin films and analyzed in terms of the copercolation model. In addition, performance characteristics relevant for flexible and transparent applications are discussed. The new TCEs are promising, but significant work must be done to ensure earth abundance, stability, and reliability so that they can eventually replace traditional ITO-based transparent conductors.

scholarly journals Preparation of Transparent Conductive Electrode via Layer-By-Layer Deposition of Silver Nanowires and Its Application in Organic Photovoltaic Device

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 46 ◽  
Author(s):  
B. Tugba Camic ◽  
Hong In Jeong ◽  
M. Hasan Aslan ◽  
Arif Kosemen ◽  
Seongbeom Kim ◽  
...  
Keyword(s):  
Sheet Resistance ◽  
Indium Tin Oxide ◽  
Silver Nanowires ◽  
Optical Transmittance ◽  
Photovoltaic Device ◽  
Organic Photovoltaic ◽  
Layer By Layer ◽  
Transparent Conductive Electrode ◽  
Glass Substrates ◽  
Organic Photovoltaic Device

Solution processed transparent conductive electrodes (TCEs) were fabricated via layer-by-layer (LBL) deposition of silver nanowires (AgNWs). First, the AgNWs were coated on (3-Mercaptopropyl)trimethoxysilane modified glass substrates. Then, multilayer AgNW films were obtained by using 1,3-propanedithiol as a linker via LBL deposition, which made it possible to control the optical transmittance and sheet resistance of multilayer thin films. Next, thermal annealing of AgNW films was performed in order to agent their electrical conductivity. AgNW monolayer films were characterized by UV-Vis spectrometer, field emission scanning electron microscopy, optical microscopy, atomic force microscopy and sheet resistance measurement by four-point probe method. The high performances were achieved with multilayer films, which provided sheet resistances of 9 Ω/sq, 11 Ω/sq with optical transmittances of 71%, 70% at 550 nm, which are comparable to commercial indium tin oxide (ITO) electrodes. Finally, an organic photovoltaic device was fabricated on the AgNW multilayer electrodes for demonstration purpose, which exhibited power conversion efficiency of 1.1%.

Electroless Deposition of Silver Nanowires Using Waste Ethylene Glycol for Highly Transparent Flexible Conducting Electrodes

2018 ◽  
Vol 775 ◽  
pp. 254-259
Author(s):  
Nathaniel de Guzman ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Ethylene Glycol ◽  
Indium Tin Oxide ◽  
Silver Nanowires ◽  
Average Length ◽  
Average Diameter ◽  
Optical Transmittance ◽  
Transparent Conductive Electrode ◽  
Transparent Conducting ◽  
Better Than ◽  
Excellent Stability

High aspect ratio silver nanowires (AgNWs) with an average length of 40 μm and average diameter of 88 nm were successfully synthesized using waste ethylene glycol as solvent and reducing agent. Silver nanowires with an average length and diameter of 32 μm and 122 nm, were produced after the third cycle of being reused. A transparent conducting film with a sheet resistance of 69 Ω/sq and optical transmittance of 91% was fabricated by Meyer rod coating an ink formulation of AgNWs dispersed in hydroxyethyl celullose (HEC)/methanol/deionized water. The low resistance of the AgNW networks was maintained even after 1000 bending cycles due to HEC acting as binder for the nanowires. The AgNWHEC transparent conductive electrode performed better than bare AgNWs and indium tin oxide (ITO) on polyethylene terephthalate (PET) substrate after several bending cycles. The AgNW-HEC electrode also showed excellent stability against corrosion.

Graphene Based Transparent Conductive Electrode

2012 ◽  
Vol 468-471 ◽  
pp. 1823-1826 ◽  
Author(s):  
Ya Nan Wang ◽  
Peng Fei Gu ◽  
Jia Jia Cao ◽  
Tian Quan Lv ◽  
Tie Qiang Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Sheet Resistance ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Oxide Films ◽  
Good Alternative ◽  
Transparent Conductor ◽  
Transparent Conductive Electrode ◽  
Reduced Graphene

As indium tin oxide (ITO) can not meet the demands of many devices due to its fragility, graphene seems to be a good alternative for transparent conductor purpose. Here we employ two methods to prepare graphene oxide films, and then process them with hydroiodic acid (HI) for reduction, aiming to get an optimized scheme and higher film quality. Finally the reduced graphene oxide films with transmittance of 70~80% at 550nm show sheet resistance of <10kΩ, which are good enough for transparent conductor uses. This study portends a promising future in this field.

Screen Printing Fine Pitch Stretchable Silver Inks onto a Flexible Substrate for Wearable Applications

2018 ◽  
Vol 2018 (1) ◽  
pp. 000665-000671
Author(s):  
Jianbiao Pan ◽  
Malcolm Keif ◽  
Joshua Ledgerwood ◽  
Xiaoying Rong ◽  
Xuan Wang
Keyword(s):  
Sheet Resistance ◽  
Flexible Electronics ◽  
Screen Printing ◽  
Flexible Substrate ◽  
Thermoplastic Polyurethane ◽  
Organic Substrate ◽  
Printing Process ◽  
Silver Ink ◽  
Fine Pitch

Abstract The lightweight and bendable features of printed flexible electronics are increasingly attractive. Currently stretchable silver inks are formulated for wide traces, typically larger than 2 mm. To attach ultra-thin silicon chips that have fine pitch onto printed organic substrate, it is necessary to print fine trace width/space that matches the pitch of the chips, which may be less than 200 microns. This paper presents the development and optimization of the screen printing process for printing stretchable silver ink onto stretchable thermoplastic polyurethane (TPU) substrate. A test vehicle was designed including 50 μm/5 mm (line width/line length) to 350 μm/35 mm lines (at 4 biases). The stretchable ink selected was DuPont PE 873 and Dupont's PE 5025 ink (non-stretchable conductive flake silver) was used as a “control” to baseline the printing process. The substrate used was Bemis TPU ST604. The experiment was done on a DEK Horizon 03i printer. A DEK squeegee 200 (Blue) and a DEK 265 flood bar (200 mm) were used. A 2-level factorial design with three replicates was selected to investigate the effect of process parameters on the quality of prints. The quality of the prints is characterized by 1) resistance of traces, 2) sheet resistance, 3) z-axis height, and 4) trace width/spacing. We observed significant noise in the z-axis printed silver ink height measured by profilometry and concluded z-axis height is not a good response variable for characterizing screen printing stretchable silver ink onto TPU substrate, mainly due to high roughness of the TPU substrate. We proposed calculated sheet resistance based on the measured resistance value, trace width, and trace length, which can replace trace height measurements on rough profile substrates. We found that squeegee pressure and emulsion thickness have statistically significant effects on calculated sheet resistance of print traces while print speed does not have statistically significant effects. In our experiment setting levels, the lower the squeegee pressure, the lower the calculated sheet resistance that is achieved. The emulsion with higher emulsion over mesh (EOM) is better than the emulsion with lower EOM since it can achieve lower sheet resistance. After optimizing the screen printing process, we were able to print 100 μm (4 mils) trace width and spacing with high consistency.

scholarly journals Pulsed Electrodeposition for Copper Nanowires

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 218 ◽  
Author(s):  
Duc-Thinh Vuong ◽  
Ha-My Hoang ◽  
Nguyen-Hung Tran ◽  
Hyun-Chul Kim
Keyword(s):  
Sheet Resistance ◽  
Indium Tin Oxide ◽  
Transparent Electrode ◽  
Pulse Frequency ◽  
Transparent Conductors ◽  
Copper Nanowires ◽  
Ambient Conditions ◽  
Smart Windows ◽  
Promising Alternative ◽  
Flexible Polymer

Copper nanowires (Cu NWs) are a promising alternative to indium tin oxide (ITO), for use as transparent conductors that exhibit comparable performance at a lower cost. Furthermore, Cu NWs are flexible, a property not possessed by ITO. However, the Cu NW-based transparent electrode has a reddish color and tends to deteriorate in ambient conditions due to the oxidation of Cu. In this paper, we propose a pulsed-current (PC) plating method to deposit nickel onto the Cu NWs in order to reduce oxidation over a 30-day period, and to minimize the sheet resistance. Additionally, the effects of the pulse current, duty cycle, and pulse frequency on the performance of the Cu–Ni (copper–nickel) NW films have also been investigated. As a result, the reddish color of the electrode was eliminated, as oxidation was completely suppressed, and the sheet resistance was reduced from 35 Ω/sq to 27 Ω/sq. However, the transmittance decreased slightly from 86% to 76% at a wavelength of 550 nm. The Cu–Ni NW electrodes also exhibited excellent long-term cycling stability after 6000 bending cycles. Our fabricated Cu–Ni electrodes were successfully applied in flexible polymer-dispersed liquid crystal smart windows.

scholarly journals Fatigue-free, superstretchable, transparent, and biocompatible metal electrodes

2015 ◽  
Vol 112 (40) ◽  
pp. 12332-12337 ◽  
Author(s):  
Chuan Fei Guo ◽  
Qihan Liu ◽  
Guohui Wang ◽  
Yecheng Wang ◽  
Zhengzheng Shi ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Indium Tin Oxide ◽  
Large Strain ◽  
Transparent Conductors ◽  
Practical Applications ◽  
Highly Stretchable ◽  
Implantable Electronics ◽  
Electronic Conductors ◽  
Strained Materials ◽  
Original Configuration

Next-generation flexible electronics require highly stretchable and transparent electrodes. Few electronic conductors are both transparent and stretchable, and even fewer can be cyclically stretched to a large strain without causing fatigue. Fatigue, which is often an issue of strained materials causing failure at low strain levels of cyclic loading, is detrimental to materials under repeated loads in practical applications. Here we show that optimizing topology and/or tuning adhesion of metal nanomeshes can significantly improve stretchability and eliminate strain fatigue. The ligaments in an Au nanomesh on a slippery substrate can locally shift to relax stress upon stretching and return to the original configuration when stress is removed. The Au nanomesh keeps a low sheet resistance and high transparency, comparable to those of strain-free indium tin oxide films, when the nanomesh is stretched to a strain of 300%, or shows no fatigue after 50,000 stretches to a strain up to 150%. Moreover, the Au nanomesh is biocompatible and penetrable to biomacromolecules in fluid. The superstretchable transparent conductors are highly desirable for stretchable photoelectronics, electronic skins, and implantable electronics.

Optimization of IGZO/Cu/IGZO Multilayers as Transparent Composite Electrode on Flexible Substrate by Room-temperature Sputtering and Post-Deposition Anneals

2013 ◽  
Vol 1577 ◽  
Author(s):  
Aritra Dhar ◽  
T. L. Alford
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Sheet Resistance ◽  
Room Temperature ◽  
Flexible Substrate ◽  
Middle Layer ◽  
Optical Transmittance ◽  
Optical And Electrical Properties ◽  
Composite Electrodes ◽  
Transparent Composite

ABSTRACTHighly transparent composite electrodes made of multilayers of In- and Ga-doped ZnO and Cu (IGZO/Cu/IGZO) thin films (30/3-9/30 nm thick) are deposited onto flexible substrates at room temperature and by using radio frequency magnetron sputtering. The effect of Cu thickness on the electrical and optical properties of the multilayer stack has been studied in accordance with the Cu morphology. The optical and electrical properties of the multilayers are studied with the UV–Vis spectrophotometry, Hall measurement and four point probe analyses. Results are compared with those from a single IGZO layered thin film. The average optical transmittance and sheet resistance both decreases with increase of copper thickness and has been optimized at 6 nm Cu middle layer thickness. The Haacke figure of merit (FOM) has been calculated to evaluate the performance of the films. The highest FOM achieved is 6 x 10-3 Ω-1 for a Cu thickness of 6 nm with a sheet resistance of 12.2 Ω/sq and an average transmittance of 86%. The multilayered thin films are annealed upto 150 °C in vacuum, forming gas and O2 environments and the optical and electrical properties are studied and compared against the as-deposited samples. Thus IGZO/Cu/IGZO multilayer is a promising flexible electrode material for the next-generation flexible optoelectronics.

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