A Flexible and Robust Transparent Conducting Electrode Platform

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A Flexible and Robust Transparent Conducting Electrode Platform Using Electroplated Silver Grid/Surface-Embedded Silver Nanowire Hybrid Structure Junho Jang, Hyeon-Gyun Im, Jungho Jin, Jaemin Lee, Jung-Yong Lee, and Byeong-Soo Bae ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.6b07140 • Publication Date (Web): 16 Sep 2016 Downloaded from http://pubs.acs.org on September 18, 2016

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ACS Applied Materials & Interfaces

A Flexible and Robust Transparent Conducting Electrode Platform Using Electroplated Silver Grid/Surface-Embedded Silver Nanowire Hybrid Structure Junho Jang†, Hyeon-Gyun Im†, Jungho Jin∥, Jaemin Lee,‡ Jung-Yong Lee‡ and Byeong-Soo Bae†* †

Department of Materials Science and Engineering, Korea Advanced Institute of Science and

Technology (KAIST), Daejeon, Republic of Korea ‡

Graduate School of Energy, Environment, Water and sustainability (EEWS), Korea

Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea ∥

School of Materials Science and Engineering, University of Ulsan, Ulsan, Republic of

Korea KEYWORDS electroplating, metal grid, silver nanowire, transparent conducting electrode, touch-screen panel

ACS Paragon Plus Environment


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Abstract In this paper, we report flexible transparent conducting electrode (TCE) film using a silver grid (Ag grid)/silver nanowire (AgNW) hybrid structure (AG/NW-GFRHybrimer). The AG/NW-GFRHybrimer consists of an AgNW-embedded glass-fabric reinforced plastic film (AgNW-GFRHybrimer) and an electroplated Ag grid. The AgNW-GFRHybrimer is used as a flexible transparent substrate and a seed layer for electroplating. The Ag grid is fabricated via an all-solution-process; grid pattern is formed using conventional photolithography and Ag is deposited through electroplating. The AG/NW-GFRHybrimer exhibits excellent optoelectrical properties (T = 87 %, Rs = 13 Ω/sq), superior thermal stability (250 oC for 720 min. & 85 oC/85 %RH for 100 hours), and outstanding mechanical flexibility (bending radius = 1 mm for 2000 cycles). Finally, a touch-screen panel (4-wire resistive type) was fabricated using the AG/NW-GFRHybrimer to demonstrate its potential for use in actual opto-electronic applications.


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1. Introduction Transparent conducting electrode (TCE) is a key component of various opto-electronic devices such as organic light-emitting diodes,1 organic solar cells (or perovskite solar cells),2, 3, 18

and touch-screen panels (TSPs).4,

5, 6

Tin doped indium oxide (ITO), the most

commonly used TCE material, has limitations for use in flexible opto-electronic devices due to the scarcity of indium, the material’s inherent brittleness, and the requirement of a vacuum process.7 Graphene,8 carbon nanotube (CNT),9 conducting polymer,10 and metal nanowire (NW)11 are potential alternatives for replacing ITO. Random networks of metal NW are emerging due to their high optical transmittance, low electrical sheet resistance, and superior flexibility.12,

13

However, high contact resistance

between individual nanowires, rough surface topography, and thermal/chemical instability of the metal NW TCEs remain as problems for the viable use of this material.14, 15 In particular, the high contact resistance at wire-to-wire junctions is a critical issue for the fabrication of high performance metal NW TCEs.5,

16

Junction resistance of metal NW can be greatly

decreased by several types of metal NW/carbon material composite18 and post-treatment, including thermal annealing,11 wet chemical coating,17 nanosoldering,4 and plasmon-induced chemical reaction using nanoparticles.3 To date, continuous metallic networks such as metal nanotrough5, 6, 19 and metal grid20, 21 have been investigated. Particularly, the metal grid is a promising structure for highperformance TCEs due to its junction-free characteristic.20 To fabricate metal grid TCEs, grid patterns are formed via various methods such as conventional photolithography,22, cracking template method,24 and transfer printing;20,

25

23

the

then, metals are deposited using

vacuum processes.26 Although vacuum processes produce high quality metals, problems of



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cost-effectiveness and excessive time consumption remain.27 Other methods for depositing metal include solution-processes such as ink-jet printing,28 electrohydrodynamic (EHD) jet printing,29 electroless deposition,23 and electroplating.21, 22 In particular, electroplating is a deposition method that can be employed to produce dense and uniform metal thin film on a surface via the action of an electric current.30 However, a conductive seed layer, and complicated processes such as etching and lift-off, are required for electroplating. Herein, we propose a metal (Ag) grid/AgNW hybrid TCE (AG/NW-GFRHybrimer) film. The AG/NW-GFRHybrimer film is composed of an electroplated metal grid and surface embedded AgNW networks. In our previous work, we reported monolithically surface embedded AgNW glass-fabric reinforced plastic film (AgNW-GFRHybrimer); this film has a very smooth surface topology (< 2 nm), high transparency (T = 90 %),31,

32

excellent

thermal/chemical stability,15 and a low coefficient of thermal expansion (CTE) (~15 ppm oC1 33

).

In this work, we used the AgNW-GFRHybrimer film as a seed layer for electroplating

and as a flexible substrate. A silver grid was formed via photolithography (patterning) and electroplating (metal deposition). Our AG/NW-GFRHybrimer film showed excellent optoelectrical properties, long-term stability against oxidation at high temperature and chemicals, and superior flexibility. Finally, a touch-screen panel (4-wire resistive type) was fabricated using the AG/NW-GFRHybrimer films to demonstrate its potential for actual opto-electronic devices. 2. Experiment Section 2.1. Synthesis of matrix resin The matrix resin, which is a transparent UV-curable thermoset resin, was synthesized by simple sol-gel condensation reaction.34 2-(3, 4-epoxycyclohexyl)ethyltrimethoxysilane (ECTS, Shin-Etsu) and diphenylsilanediol (DPSD, Gelest) were mixed at 80 oC for 4 hours


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under N2 purging. The molar ratio of ECTS to DPST was 1 to 1.5. Barium hydroxide monohydrate (Ba(OH)2·H2O, Sigma-Aldrich) was added as a base catalyst to promote the reaction. Bis[1-ethyl(3-oxetanyl)]methyl ether (DOX, Toagosei) as a cross-linker and triarylsulfonium hexafluoroantimonate salt (Sigma-Aldrich) as a photo-initiator were added after the sol-gel condensation reaction. Finally, cycloaliphatic epoxy oligosiloxane (Hybrimer) was obtained. 2.2. Fabrication of AG/NW-GFRHybrimer 2.2.1. Fabrication of basal AgNW-GFRHybimer AgNW solution (Nanopyxis) were filtered using nylon membrane filter (0.2 µm pores, 47mm diameter). AgNW networks on the filter were directly transferred to a donor glass using a compressor (compressing pressure is about 14 MPa) for a few seconds. The donor glass was heated at 100 oC on a hot plate for 30 minutes to evaporate residual solvent or polymer. The AgNW-GFRHybrimer film was fabricated by transferring the AgNW networks onto the surface of a base GFRHybrimer film via a vacuum-bag molding process. The preformed AgNW network on the donor glass was brought into contact with a glass-fabric cloth impregnated with a matrix resin on the second donor glass, and the assembly was compressed. This was followed by vacuum bag molding and ultraviolet curing. Finally, the separation of the two donor glasses resulted in the transparent and freestanding AgNWGFRHybrimer film of which the thickness was ca. 60 µm. 2.2.2. Photolithography The transparent negative photoresist (THB-126N, JSR micro) was mixed with propylene glycol monomethyl ether acetate (PGMEA, Aldrich) as solvent to optimize thickness (2 µm). The amount of PGMEA was about 50 wt% of the amount of the original photoresist. The



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blended photoresist was coated on the AgNW-GFRHybrimer film using a spin coating method (spin rate = 5000 rpm, spin time = 100 seconds). The coated photoresist was softbaked for 5 minutes at 110 oC on a hotplate. Using a photomask and UV lithography process (λ = 365 nm), the grid pattern was transferred onto the photoresist layer. The regions, which did not exposed to UV light on the photoresist, were then removed with 2.5 wt% of tetramethylammonium hydroxide (TMAH from Aldrich) in water for 210 seconds; after the sample was rinsed with distilled water and blown with nitrogen gas, the patterned AgNWGFRHybrimer film was hard-baked at 120 oC for 5 minutes. 2.2.3. Electroplating The PR patterned AgNW-GFRHybrimer, which was applied as a working electrode for electroplating, was connected to copper wire. To reduce the contact resistance, the electrical contact was directly created using silver paste on the upper part of the AgNW-GFRHybrimer. The counter electrode was formed using platinum wire (Aldrich). The electrolyte was composed of 0.05M of KAg(CN)2 (Aldrich) and 0.25 M of Na2CO3 (Aldrich). The electric current flow was kept constant at 2.74 mA during the plating process. 2.3. Characterization The sheet resistance (Rs) and the total transmittance (Ttot) were measured using a 4 point probe sheet resistance meter and a UV spectrometer (UV-310PC, SHIMADZU), respectively. The SEM images were obtained using a field emission scanning electron microscope (Nova 230, FEI Company). XRD analysis was conducted using a thin-film X-ray diffractometer (Ultima lV, RIGAKU). The XPS spectra were obtained using a multipurpose X-ray photoelectron spectroscope (Sigma Probe, Thermo VG Scientific). 2.4. Fabrication of touch-screen panel


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The commercial negative photoresist, which had been used in the previous process of photolithography, was spin-coated (800 rpm for 40 seconds) two times onto the AG/NWGFRHybrimer film (bottom electrode film) and then patterned using a photolithography process to form an insulating spacer dot (diameter = 50 µm, distance between spacers = 4 mm). Two electrical outlets were created on the bottom electrode film and another AG/NWGFRHybrimer film (top electrode film). The top electrode film was attached to the bottom electrode film with commercial polyimide tape. Finally, the fabricated TSP device was connected to a USB controller via 4 copper wire. 3. Results and Discussion Figure 1a shows the entire fabrication process of the AG/NW-GFRHybrimer;31, 32 (i) AgNW networks were deposited on a donor glass using vacuum filtration.1 (ii) A matrix resin, sol-gel derived cycloaliphaticepoxysiloxane,34 was impregnated with a glass fabric sheet on another donor glass. (iii) The AgNW network was directly transferred onto the matrix resin impregnated glass fabric sheet using a vacuum-bag molding process. (iv) After UV curing, the two pieces of donor glass were detached, and the AgNW-GFRHybrimer film was obtained. (v) A transparent negative photoresist (PR) was coated on the AgNWGFRHybrimer film; at this stage, to ensure adhesion between the PR and the AgNWGFRHybrimer film, Ar plasma treatment was performed before PR coating. (vi) After PR coating, UV light was exposed through a photomask, and a developing process was carried out; during these processes, the sheet resistance (Rs) of the AgNW-GFRHybrimer was retained because the AgNW networks were protected by a chemically stable hybrid matrix. (vii) Electroplating process was applied to form a metal grid on the PR patterned AgNWGFRHybrimer film; the embedded-AgNW network was used as a seed layer. Finally, the AG/NW-GFRHybrimer film was fabricated. Details are explained in the Experimental



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Section. Figure 1b shows a scanning electron microscope (SEM) image of the surface of the AgNW-GFRHybrimer. The AgNW networks are well-embedded on the surface of the substrate. Figure 1(c-d) display surface SEM images of the PR patterned AgNWGFRHybrimer and the AG/NW-GFRHybrimer. The grid pattern is well defined; the AgNW networks between the grid patterns can be seen. In Figure 1d, an electroplated metal line can be seen to be located between the grid patterns. Surface SEM images of the AG/NWGFRHybrimer with varying line spacing (100, 300, and 500 µm) are shown in Figure 2. A continuous electroplated metal line (width = 10 µm) can also be seen. Elemental analysis of the electroplated metal was performed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. In the XRD spectra (Figure 2e), characteristic crystalline Ag diffraction patterns can be seen: 2θ = 38o and 44o are assigned to (111) and (200), respectively.35 The Ag 3d spectra of the XPS are shown in Figure 2f. For Ag 3d, the peaks of Ag 3d3/2 and Ag 3d5/2 are positioned at 374.4 eV and 368.4 eV, respectively; those two binding energies indicate metallic Ag.36, 37 These results confirm that the metal grid/NW hybrid electrode was successfully fabricated using a surface embedded AgNW seed layer and an electroplating process. To form a metal grid via an electroplating process, the plating time and Rs of the seed layer are crucial factors that determine the uniformity of the electroplated metal. Figure 3a exhibits a plot of the Rs according to the plating time. As the plating time increased, the value of the Rs decreased. The optical transmittance (T) also decreased with increasing of the plating time (Figure 3b). The relationship of the surface morphology and the plating time was confirmed by SEM analysis (Figure 3c-f). In the case of short plating time (Figure 3c and 3d), the metal grid was incompletely formed between the PR patterned lines. On the other hand, a dense metal grid can be seen when the plating time was 7 minute (Figure 3e); the metal grid was overly grown when the plating time was more than 7 minute (Figure 3f). It should be noted


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that increasing of the plating time can create a densely deposited metal grid with decreased Rs, but the dense metal grid can cause low transmittance. Considering the results according to the plating time, we optimized the plating time at 7 minute. Another important factor is the Rs of the AgNW seed layer because this value affects the uniformity of the electroplated metal grid. Figure S1 shows photographs and SEM images of the electroplated metal with varying values of Rs of the AgNW seed layer. In the case of a high density of the AgNW seed layer, which means a low Rs of the AgNW-GFRHybrimer, the electroplated metal grid is uniformly and densely formed (Figure S1a). On the other hand, the electroplated metal grid, when based on a low density of the AgNW seed layer, showed a partially formed metallic layer with many defects (Figure S1c). Although a high density of the AgNW seed layer in the substrate (AgNW-GFRHybrimer) can provide a large number of growth sites for the conductive layer, this can degrade the optical transmittance. Therefore, we optimized the Rs of the AgNWGFRHybrimer at 100 Ω/sq to reflect the optimized AgNW concentration because metal grid can be densely formed (Figure S1b) with high optical transmittance according to results of Figure 3b. To evaluate the opto-electrical property of the AG/NW-GFRHybrimer using optimized conditions, the total transmittance at 550 nm (Ttot) and the Rs of the AG/NW-GFRHybrimer were measured. Figure 4 shows a plot of Ttot versus Rs for the AG/NW-GFRHybrimer fabricated with varying of the line spacing and density of the AgNW seed layer; blue and red stars indicate the electroplated metal grids that were fabricated under conditions of low Rs (~10 Ω/sq, L-AG/NW-GFRHybrimer) and high Rs of the AgNW-GFRHybrimer (~100 Ω/sq, H-AG/NW-GFRHybrimer), respectively. For comparison, reference data sets from various recently reported metal grid TCEs are also included.7,

20-22, 24, 26, 29

Our AG/NW-

GFRHybrimer shows opto-electrical performance comparable to those of other metal grid TCEs. The total transmittance spectra of the bare GFRHybrimer and of the AG/NW-



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GFRHybrimer are shown in Figure S2. Wider line spacing of the grid shows the higher transmittance, as well as the higher Rs.20 The L-AG/NW-GFRHybrimer shows lower transmittance compared with the H-AG/NW-GFRHybrimer. Summarized data for Ttot and Rs are shown in Table 1. The value of Rs of the electroplated metal grid is much lower than that of the initial AgNW-GFRHybrimer film because a junction-free grid structure has continuous electrical pathways.6,

32

To determine the opto-electrical performance of the AG/NW-

GFRHybrimer, a figure of merit (ΦTC) is introduced. The ΦTC value can be calculated using the Haacke equation:38

ΦTC =

T 10 Rs

(1)

where T is the optical transmittance at 550 nm of wavelength and Rs is the electrical sheet resistance. The higher the ΦTC value, the better opto-electrical performance of the TCE will be. The calculated ΦTC values are also shown in Table 1. For comparison, ΦTC values of commercial ITO/PET film were also calculated. The average ΦTC values are 13.7 x 10-3 Ω-1 (L-AG/NW-GFRHybrimer) and 17.87 x 10-3 Ω-1(H-AG/NW-GFRHybrimer). In the case of the H-AG/NW-GFRHybrimer, the ΦTC value is much higher than that of the commercial ITO film. On the other hand, the ΦTC value of the L-AG/NW-GFRHybrimer is much lower than that of the ITO film due to the low transmittance of the AgNW-GFRHybrimer. In the case of 100 µm line spacing of the L-AG/NW-GFRHybrimer, the highest ΦTC was obtained due to the low Rs value. Compared with those of other metal grid TCEs and commercial ITO/PET film, our AG/NW-GFRHybrimer has excellent opto-electrical properties. The thermal-oxidation resistance of the TCE is an important issue in optoelectronic device application.20 For this reason, various thermal-oxidation tests of the AG/NW-GFRHybrimer were performed. To evaluate the high temperature endurance, the AG/NW-GFRHybrimer was


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oven-annealed at 200, 250, and 300 oC in ambient atmosphere for 12 hours using a resistance-meter at intervals of 30 minute. The normalized resistance (R/R0) was measured during thermal aging. Figure 5a shows the thermal aging test results. For the 200 and 250 oC temperature conditions, the resistance values were retained after an aging time of 12 hours. The electrical performance of the AG/NW-GFRHybrimer was stable even in conditions of 2 hours at 300 oC. However, further aging of the 300 oC-annealed sample resulted in an exponential increase of the resistance. This result was further evaluated using XRD and SEM analyses. In the XRD pattern (Figure S3a), metallic Ag phases (2θ = 38o and 2θ = 44o) can be seen and silver oxide peaks were not observed; this means that the electroplated Ag was not oxidized during the thermal aging test.35 Correspondingly, the SEM images of the 200 and 250 oC-annealed samples show that these samples retained their surface morphology without any disconnections or defects (Figure S3b and Figure S3c). In contrast, the cracked surface of the 300 oC-annealed sample can be seen (Figure S3d). The destruction of the PR causes a disconnection of the metal grid lines, resulting in a degradation of the electrical performance. The thermal stability of AG/NW-GFRHybrimer was further evaluated in an elevated temperature test; the AG/NW-GFRHybrimer was annealed on a hot plate with a ramp rate of 5 oC min-1 (Figure 5b). Every minute, the resistance value was checked in situ. For the in situ measurement of the resistance, silver paste was used to directly create two separate electrical contact points on the metal grid (inset in Figure 5b). For comparison, only Ag grid, AgNW on glass and AgNW-GFRHybrimer were also tested. Only Ag grid was also fabricated via electroplating process using ITO glass.21 In fabrication of only Ag grid, PR was removed after electroplating to check the effect of PR layer. Upon annealing, the resistance of AG/NW-GFRHybrimer maintained its initial value until 520

o

C and then increased

exponentially. In contrast, other samples were degraded catastrophically at lower temperature (bare AgNW: 390 oC, AgNW-GFRHybrimer: 420 oC and only Ag grid: 450 oC). The reason



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for the surging resistance is that the degraded PR caused a disconnection of the electroplated metal grid lines (Figure S4); this result is similar to results of previous thermal aging tests. The stability of the TCEs against high thermal and humidity environments is another important factor because moisture in the air can cause corrosion of Ag.39 The AG/NWGFRHybrimer was exposed to high humidity condition (85 % relative humidity, RH) at 85 oC for 100 hours (Figure S5). Every 5 seconds, the resistance of the AG/NW-GFRHybrimer was measured in situ. Figure S5a shows the changes in the resistance of the AG/NWGFRHybrimer during the 85 oC/85 %RH aging test. The resistance of the AG/NWGFRHybrimer retained its initial value during the test. XRD and SEM analyses were performed to check the oxidation and surface morphology of the AG/NW-GFRHybrimer. The AG/NW-GFRHybrimer was not oxidized (Figure S5b) and showed a clear surface without any defects (Figure S5c). The improved thermal-oxidation stability of the AG/NWGFRHybrimer film may be the result of the remaining PR protecting the Ag grid from oxidation. Robustness to chemical attack is another essential requirement to be addressed for viable application of the AG/NW-GFRHybrimer. Most of the device fabrication processes involve harsh chemical reagents that can degrade an Ag-based electrode.15 To determine the chemical stability of our AG/NW-GFRHybrimer, 5 wt% of K2S aqueous solution as oxidative reagent was used; this was done because silver can be subject to sulfurization under exposure to sulfur-containing compounds (Figure 5c). 37, 40 The K2S solution was dropped on the surface of a metal grid that has two separate electrical contacts fabricated using silver paste (inset in Figure 5c). During the test, the normalized resistance was measured in-situ. Bare AgNW, AgNW-GFRHybrimer and only Ag grid were also checked for comparison. The AgNWGFRHybrimer film shows a dramatic increase in Rs after 150 seconds even though the degradation time of AgNW-GFRHybrimer is prolonged compared with bare AgNW and only


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Ag grid. In contrast, the resistance of the AG/NW-GFRHybrimer retained its initial value until 1400 seconds. After that time, the electrical performance was significantly degraded. The embedded-type TCEs (AG/NW-GFRHybrimer and AgNW-GFRHybrimer) show better tolerance against chemical-attack than non-embedded TCEs (bare AgNW and only Ag grid). In case of AgNW-GFRHybrimer, matrix resin protects AgNW networks. On the other hand, remained PR layer can act as protecting layer of Ag grid. To confirm the oxidation of Ag, XRD analysis was carried out (Figure S6a). No metallic Ag peaks were detected. SEM was also used to confirm the surface morphology (Figure S6b). In the SEM image, clear Ag gird lines can be seen, without any disconnections. From these results, the Ag grid can be said to have been oxidized by the sulfur-containing solution. The AG/NW-GFRHybrimer exhibited improved chemical oxidation-resistance compared with the case of the only-AgNW embedded TCE15 and only Ag grid. The mechanical flexibility of the TCE is a critical issue if this material is to be used in flexible opto-electronics. To evaluate the flexibility of our AG/NW-GFRHybrimer, bending durability was checked using a bending test machine (Figure 5d). Two types of bending tests were carried out: inner and outer bending (inset in Figure 5d, bending radius = 1 mm). For comparison, a commercial ITO/PET film (ITO: 100 nm, PET: 150 µm) was also tested. The AG/NW-GFRHybrimer exhibited a retention of its electrical performance after 2000 bending cycles of inner and outer bending. In contrast, the resistance of the commercial ITO/PET film was degraded catastrophically after only a few bending cycles. Considering its excellent flexibility, the AG/NW-GFRHybrimer has strong potential as a TCE platform in flexible optoelectronic device applications. To confirm the potential of the AG/NW-GFRHybrimer as a TCE platform for flexible optoelectronic applications, a 4-wire resistive type touch-screen panel (TSP) was fabricated



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using the AG/NW-GFRHybrimer films (Figure 6). Figure 6a shows the schematic structure of the fabricated TSP. Both top and bottom electrodes were composed of AG/NW-GFRHybrimer. The commercial PR (THB-126N), which was used to form grid patterns in this work, was applied as a spacer. The TSP devices operate well; it was possible to use these devices to write the letters “KAIST”, as can be seen in Figure 6c. Based on the above results, AG/NWGFRHybrimer films can be considered as promising TCE platforms for flexible optoelectronic applications. 4. Conclusion In conclusion, as a flexible TCE platform, we have fabricated an all-solution-processed metal grid TCE (AG/NW-GFRHybrimer) based on a surface embedded AgNW seed layer. The metal grid was fabricated using a conventional photolithography process and electroplating. AgNW-embedded glass-fabric reinforced plastic film (AgNW-GFRHybrimer) was used as a transparent conducting substrate and seed layer for electroplating. The fabricated AG/NW-GFRHybrimer shows excellent opto-electrical performance; for example, the values of T = 87 % and Rs = 13 Ω/sq, remarkable thermal/chemical stability and outstanding mechanical flexibility (2000 bending cycles with 1 mm of bending radius). Finally, a 4-wire resistive type touch-screen panel (TSP) was fabricated to demonstrate the potential of this material for use in flexible opto-electronic applications. The TSP device showed stable operation. We expect that our AG/NW-GFRHybrimer can be considered a promising candidate as a replacement material for ITO and metal nanowire TCEs in flexible optoelectronic applications.


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FIGURES

Figure 1. (a) Schematic illustration for the fabrication of AG/NW-GFRHybrimer. (i) AgNW was coated on 1st



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donor glass using spary deposition or vacuum filtration. (ii) The matrix resin was impregnated on 2nd donor glass placing the glass fabric sheet. (iii) AgNW was directly transferred using AgNW coated 1st donor glass & perform the UV curing. (iv) Two donor glasses were detached to obtain free standing AgNW-GFRHybrimer after UV curing. (v) The transparent negative photoresist was coated on AgNW-GFRHybrimer using conventional spin coating system. (vi) UV light (λ=365 nm) was exposed on PR coated AgNW-GFRHybrimer using photomask and developed using commercial developer. (vii) The conductive layer between PR patterned lines was created using electroplating process (AG/NW-GFRHybrimer). Plating Bath was composed of platinum (counter electrode), AgNW-GFRHybrimer (working electrode) and electrolyte. (b-d) tilted SEM images of AgNW-GFRHybrimer (b), PR patterned AgNW-GFRHybrimer (c) ,and AG/NW-GFRHybrimer (d).

Figure 2. (a) A photograph of the AG/NW-GFRHybrimer film. (b-d) Surface SEM images of the AG/NWGFRHybrimer film according to various line spacing; the line spacing = (b) 100, (c) 300, and (d) 500 µm. The line width of all samples is 10 µm. All scale bars in SEM images are 200 µm. (e) The XRD spectra of the AG/NW-GFRHybrimer. Two separated peaks were positioned 38o of Ag (111) and 44o of Ag (200) indicating crystalline Ag phase. (f) The XPS spectra of the AG/NW-GFRHybrimer. In Ag 3d scan, Ag 3d3/2 (374.4 eV) and Ag 3d5/2 (368.4 eV) indicated metallic Ag.


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Figure 3. Plots of sheet resistance (a) and transmittance (b) according to electroplating time. (c-f) Surface SEM images of the AG/NW-GFRHybrimer films according to the electroplating time; (c) 5, (d) 6, (e) 7, and (f) 20 min.

Figure 4. A plot of total transmittance (Ttot) at 550 nm as function of sheet resistance (Rs) for AG/NWGFRHybrimer films and several state-of-the-art metal grid TCEs. Blue and red stars represent L-AG/NWGFRHybrimer and H-AG/NW-GFRHybrimer, respectively.



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Figure 5. (a-b) Thermal-oxidation stability of the AG/NW-GFRHybrimer films. (a) A plot of normalized resistance change (R/R0) versus aging time at 200 oC (Red), 250 oC (Blue) and 300 oC (Orange) under ambient air condition. (b) A plot of normalized resistance change (R/R0) with elevating temperature (ramp rate = 5 o C/min). (c) Chemical stability result of the AG/NW-GFRHybrimer film using 5 wt% K2S solution. In (c-d), AgNW on glass (Black), AgNW-GFRHybrimer (Blue) and only Ag grid (Orange) also represent for comparison. (d) Mechanical stability of the AG/NW-GFRHybrimer film with 1 mm of bending radius. Red and blue line are inner bending and outer bending, respectively.


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Figure 6. A touch-screen panel (TSP) device using the AG/NW-GFRHybrimer films. (a) A schematic illustration of the TSP device. (b) A photograph of the TSP device. (c) Photographs for the operating TSP device by human hand. The written characters are “KAIST”.



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TABLES Line Spacing

T (at 550nm, %)

Rs (Ω/sq)

FoM (ΦTC, Ω-1)

Bare GFRHybrimer

90

-

-

100㎛ (L-AG/NW-GFRHybrimer)

74.5

2

26.3 x 10-3

300㎛ (L- AG/NW-GFRHybrimer)

76.9

9

8.04 x 10-3

500㎛ (L- AG/NW-GFRHybrimer)

77.2

11

6.84 x 10-3

100㎛ (H- AG/NW-GFRHybrimer)

84.5

10

18.6 x 10-3


87

13

19.1 x 10-3


87.2

16

15.9 x 10-3

ITO (100 nm) / PET (150 µm) film

85

15

13.1 x 10-3

Table 1. Summarized T, Rs and Figure of merit (ΦTC) values of AG/NW-GFRHybrimer films and commercial ITO/PET film.


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SUPPORTING INFORMATION Surface morphology of electroplated Ag grid with sheet resistance (Rs) of seed layer. Total transmittance spectra of AG/NW-GFRHybrimer with line spacing and Rs of seed layer. XRD and SEM analysis after thermal aging test. SEM image after elevating temperature test. Thermal/humidity test (85 oC/85 %RH) results. XRD and SEM analysis after chemical stability test. AUTHOR INFORMATION

Corresponding Author *E-mail: [email protected]

Notes The authors declare no competing financial interest. ACKNOWLEDGMENT This work was supported by Wearable Platform Materials Technology Center (WMC) funded by the National Research Foundation of Korea (NRF) Grant of the Korean Government (MSIP) (NRF-2016R1A5A1009926 and NRF-2015R1A2A1A15056057). This research was also supported by a grant from the Korea Evaluation Institute of Industrial Technology (Project 10051337).



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REFERENCES (1) Im, H.-G.; Jung, S.-H.; Jin, J.; Lee, D.; Lee, J.; Lee, D.; Lee, J.-Y.; Kim, I.-D.; Bae, B.-S. Flexible Transparent Conducting Hybrid Film Using a Surface-Embedded Copper Nanowire Network: A Highly Oxidation-Resistant Copper Nanowire Electrode for Flexible Optoelectronics. ACS Nano 2014, 8 (10), 10973-10979. (2) Ye, S.; Rathmell, A. R.; Chen, Z.; Stewart, I. E.; Wiley, B. J. Metal Nanowire Networks: The Next Generation of Transparent Conductors. Adv. Mater. 2014, 26 (39), 6670-6687. (3) Lu, H.; Sun, J.; Zhang, H.; Lu, S.; Choy, W. C. Room-Temperature Solution-Processed and Metal Oxide-Free Nano-Composite for the Flexible Transparent Bottom Electrode of Perovskite Solar Cells. Nanoscale 2016, 8 (11), 5946-5953. (4) Lee, J.; Lee, P.; Lee, H. B.; Hong, S.; Lee, I.; Yeo, J.; Lee, S. S.; Kim, T. S.; Lee, D.; Ko, S. H. Room‐Temperature Nanosoldering of a Very Long Metal Nanowire Network by Conducting‐Polymer‐Assisted Joining for a Flexible Touch‐Panel Application. Adv. Funct.

Mater. 2013, 23 (34), 4171-4176. (5) Wu, H.; Kong, D.; Ruan, Z.; Hsu, P.-C.; Wang, S.; Yu, Z.; Carney, T. J.; Hu, L.; Fan, S.; Cui, Y. A Transparent Electrode Based on a Metal Nanotrough Network. Nat. Nanotechnol.

2013, 8 (6), 421-425. (6) Im, H.-G.; An, B. W.; Jin, J.; Jang, J.; Park, Y.-G.; Park, J.-U.; Bae, B.-S. A HighPerformance, Flexible and Robust Metal Nanotrough-Embedded Transparent Conducting Film for Wearable Touch Screen Panels. Nanoscale 2016, 8 (7), 3916-3922. (7) Jang, Y.; Kim, J.; Byun, D. Invisible Metal-Grid Transparent Electrode Prepared by Electrohydrodynamic (EHD) Jet Printing. J. Phys. D: Appl. Phys. 2013, 46 (15), 155103. (8) Wang, X.; Zhi, L.; Müllen, K. Transparent, Conductive Graphene Electrodes for DyeSensitized Solar Cells. Nano Lett. 2008, 8 (1), 323-327.


Page 22 of 27

Page 23 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(9) Hecht, D. S.; Thomas, D.; Hu, L.; Ladous, C.; Lam, T.; Park, Y.; Irvin, G.; Drzaic, P. Carbon-Nanotube Film on Plastic as Transparent Electrode for Resistive Touch Screens. J.

Soc. Inf. Disp. 2009, 17 941-946. (10) Fan, X.; Wang, J.; Wang, H.; Liu, X.; Wang, H. Bendable ITO-Free Organic Solar Cells with Highly Conductive and Flexible PEDOT:PSS Electrodes on Plastic Substrates. ACS

Appl. Mater. Interfaces 2015, 7 (30), 16287-16295. (11) Lee, J.-Y.; Connor, S. T.; Cui, Y.; Peumans, P. Solution-Processed Metal Nanowire Mesh Transparent Electrodes. Nano Lett. 2008, 8 (2), 689-692. (12) Yang, S. B.; Choi, H.; Lee, D. S.; Choi, C. G.; Choi, S. Y.; Kim, I. D. Improved Optical Sintering Efficiency at the Contacts of Silver Nanowires Encapsulated by a Graphene Layer.

Small 2015, 11 (11), 1293-1300. (13) Kang, B.; Yun, J.; Kim, S. G.; Yang, M. Adaptive Fabrication of a Flexible Electrode by Optically Self‐Selected Interfacial Adhesion and Its Application to Highly Transparent and Conductive Film. Small 2013, 9 (12), 2111-2118. (14) Shiau, Y.-J.; Chiang, K.-M.; Lin, H.-W. Performance Enhancement of Metal NanowireBased Transparent Electrodes by Electrically Driven Nanoscale Nucleation of Metal Oxides.

Nanoscale 2015, 7 (29), 12698-12705. (15) Im, H.-G.; Jin, J.; Ko, J.-H.; Lee, J.; Lee, J.-Y.; Bae, B.-S. Flexible Transparent Conducting Composite Films Using a Monolithically Embedded Agnw Electrode with Robust Performance Stability. Nanoscale 2014, 6 (2), 711-715. (16) Hsu, P.-C.; Kong, D.; Wang, S.; Wang, H.; Welch, A. J.; Wu, H.; Cui, Y. Electrolessly Deposited Electrospun Metal Nanowire Transparent Electrodes. J. Am. Chem. Soc. 2014, 136 (30), 10593-10596. (17) Lu, H.; Zhang, D.; Cheng, J.; Liu, J.; Mao, J.; Choy, W. C. Locally Welded Silver Nano‐ Network Transparent Electrodes with High Operational Stability by a Simple Alcohol‐Based



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Chemical Approach. Adv. Funct. Mater. 2015, 25 (27), 4211-4218. (18) Lu, H.; Zhang, D.; Ren, X.; Liu, J.; Choy, W. C. Selective Growth and Integration of Silver Nanoparticles on Silver Nanowires at Room Conditions for Transparent Nano-Network Electrode. ACS Nano 2014, 8 (10), 10980-10987. (19) An, B. W.; Hyun, B. G.; Kim, S.-Y.; Kim, M.; Lee, M.-S.; Lee, K.; Koo, J. B.; Chu, H. Y.; Bae, B.-S.; Park, J.-U. Stretchable and Transparent Electrodes Using Hybrid Structures of Graphene–Metal Nanotrough Networks with High Performances and Ultimate Uniformity.

Nano Lett. 2014, 14 (11), 6322-6328. (20) Kim, H.-J.; Lee, S.-H.; Lee, J.; Lee, E.-S.; Choi, J.-H.; Jung, J.-H.; Jung, J.-Y.; Choi, D.G. High-Durable AgNi Nanomesh Film for a Transparent Conducting Electrode. Small 2014, 10 (18), 3767-3774. (21) Khan, A.; Lee, S.; Jang, T.; Xiong, Z.; Zhang, C.; Tang, J.; Guo, L. J.; Li, W. D. High‐ Performance Flexible Transparent Electrode with an Embedded Metal Mesh Fabricated by Cost‐Effective Solution Process. Small 2016, 12 (22), 3021-3030. (22) Choi, S.; Zhou, Y.; Haske, W.; Shim, J. W. Fuentes-Hernandez, C., Kippelen, B., ITOFree Large-Area Flexible Organic Solar Cells with an Embedded Metal Grid. Org. Electron.

2015, 17, 349-354. (23) Jin, Y.; Cheng, Y.; Deng, D.; Jiang, C.; Qi, T.; Yang, D.; Xiao, F. Site-Selective Growth of Patterned Silver Grid Networks as Flexible Transparent Conductive Film by Using Poly(Dopamine) at Room Temperature. ACS Appl. Mater. Interfaces 2014, 6 (3), 1447-1453. (24) Han, B.; Pei, K.; Huang, Y.; Zhang, X.; Rong, Q.; Lin, Q.; Guo, Y.; Sun, T.; Guo, C.; Carnahan, D.; Giersig, M.; Wang, Y.; Gao, J.; Ren, Z.; Kempa, K. Uniform Self-Forming Metallic Network as a High-Performance Transparent Conductive Electrode. Adv. Mater.

2014, 26 (6), 873-877. (25) Oh, Y. S.; Choi, D. Y.; Sung, H. J. Direct Imprinting of Thermally Reduced Silver


Page 24 of 27

Page 25 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Nanoparticles Via Deformation-Driven Ink Injection for High-Performance, Flexible Metal Grid Embedded Transparent Conductors. RSC Adv. 2015, 5 (79), 64661-64668. (26) Park, J.; Hwang, J. Fabrication of a Flexible Ag-Grid Transparent Electrode Using AC Based Electrohydrodynamic Jet Printing. J. Phys. D: Appl. Phys. 2014, 47 (40), 405102. (27) Sciacca, B.; van de Groep, J.; Polman, A.; Garnett, E. C. Solution‐Grown Silver Nanowire Ordered Arrays as Transparent Electrodes. Adv. Mater. 2015, 28 (5), 905-909. (28) Jeong, J.-A.; Kim, J.; Kim, H.-K. Ag Grid/ITO Hybrid Transparent Electrodes Prepared by Inkjet Printing. Sol. Energy Mater. Sol. Cells 2011, 95 (7), 1974-1978. (29) Kang, J.; Jang, Y.; Kim, Y.; Cho, S.-H.; Suhr, J.; Hong, B. H.; Choi, J.-B.; Byun, D. An Ag-Grid/Graphene Hybrid Structure for Large-Scale, Transparent, Flexible Heaters.

Nanoscale 2015, 7 (15), 6567-6573. (30) Lou, H. H.; Huang, Y. Electroplating. Encycl. Chem. Process. Des. 2006, DOI: 10.1081/E-ECHP-120007747 (31) Jin, J.; Ko, J.-H.; Yang, S.; Bae, B.-S. Rollable Transparent Glass-Fabric Reinforced Composite Substrate for Flexible Devices. Adv. Mater. 2010, 22 (40), 4510-4515. (32) Jin, J.; Lee, J.; Jeong, S.; Yang, S.; Ko, J.-H.; Im, H.-G.; Baek, S.-W.; Lee, J.-Y.; Bae, B.S. High-Performance Hybrid Plastic Films: A Robust Electrode Platform for Thin-Film Optoelectronics. Energy. Environ. Sci. 2013, 6 (6), 1811-1817. (33) Kim, H. Y.; Jin, J.; Ko Park, S.-H.; Eom, I.-Y.; Bae, B.-S. 350 °C Processable Low-CTE Transparent Glass-Fabric-Reinforced Hybrimer Film for Flexible Substrates. J. Inf. Disp.

2015, 16 (1), 57-64. (34) Yang, S. C.; Jin, J. H.; Kwak, S.-Y.; Bae, B.-S. Thermo-Mechanical/Thermal Properties of Photo-Cationic Polymerized Cyclo-Aliphatic Epoxy Hybrid Materials. Macromol. Res.

2011, 19 (11), 1166-1171. (35) Waterhouse, G. I.; Bowmaker, G. A.; Metson, J. B.; The Thermal Decomposition of



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Silver (I, III) Oxide: A Combined XRD, FT-IR and Raman Spectroscopic Study. Phys. Chem.

Chem. Phys. 2001, 3 (17), 3838-3845. (36) Fan, W.; Jewell, S.; She, Y.; Leung, M. K. H. In Situ Deposition of Ag-Ag2S Hybrid Nanoparticles onto TiO2 Nanotube Arrays Towards Fabrication of Photoelectrodes with High Visible Light Photoelectrochemical Properties. Phys. Chem. Chem. Phys. 2014, 16 (2), 676680. (37) Elechiguerra, J. L.; Larios-Lopez, L.; Liu, C.; Garcia-Gutierrez, D.; Camacho-Bragado, A.; Yacaman, M. J. Corrosion at the Nanoscale: The Case of Silver Nanowires and Nanoparticles. Chem. Mater. 2005, 17 (24), 6042-6052. (38) Haacke, G. New Figure of Merit for Transparent Conductors. J. Appl. Phys. 1976, 47 (9), 4086-4089. (39) Jiu, J.; Wang, J.; Sugahara, T.; Nagao, S.; Nogi, M.; Koga, H.; Suganuma, K.; Hara, M.; Nakazawa, E.; Uchida, H. The Effect of Light and Humidity on the Stability of Silver Nanowire Transparent Electrodes. RSC Adv. 2015, 5 (35), 27657-27664. (40) Zeng, X. Y.; Zhang, Q. K.; Yu, R. M.; Lu, C. Z. A New Transparent Conductor: Silver Nanowire Film Buried at the Surface of a Transparent Polymer. Adv. Mater. 2010, 22 (40), 4484-4488.


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A Flexible and Robust Transparent Conducting Electrode Platform

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