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Studies on the mechanical stretchability of transparent conductive film based on graphene-metal nanowire structures.

Lee MS, Kim J, Park J, Park JU - Nanoscale Res Lett (2015)

Bottom Line: Transparent electrodes with superior flexibility and stretchability as well as good electrical and optical properties are required for applications in wearable electronics with comfort designs and high performances.High electrical and optical characteristics, superb bendability (folded in half), excellent stretchability (10,000 times in stretching cycles with 100% in tensile strain toward a uniaxial direction and 30% in tensile strain toward a multi-axial direction), strong robustness against electrical breakdown and thermal oxidation were obtained through comprehensive study.We believe that these results suggest a substantial promise application in future electronics.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Wearable Electronics Research Group, Low-Dimensional Carbon Materials Research Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798 Republic of Korea.

ABSTRACT
Transparent electrodes with superior flexibility and stretchability as well as good electrical and optical properties are required for applications in wearable electronics with comfort designs and high performances. Here, we present hybrid nanostructures as stretchable and transparent electrodes based on graphene and networks of metal nanowires, and investigate their optical, electrical, and mechanical properties. High electrical and optical characteristics, superb bendability (folded in half), excellent stretchability (10,000 times in stretching cycles with 100% in tensile strain toward a uniaxial direction and 30% in tensile strain toward a multi-axial direction), strong robustness against electrical breakdown and thermal oxidation were obtained through comprehensive study. We believe that these results suggest a substantial promise application in future electronics.

No MeSH data available.


Related in: MedlinePlus

Patterning of AgNW networks and breakdown characteristics of the hybrid pattern. (a) An optical microscope image of patterned AgNW networks as channel by using dry etching. Top inset of (a) A schematic diagram of a device layout with patterned AgNW networks as channel. Scale bar is 30 μm. SEM images of AgNW networks (b) unexposed and (c) exposed to oxygen plasma. Scale bars are 5 μm. (d) A magnified SEM image of disconnected AgNW networks after dry etching process. Scale bar is 500 nm. (e) Comparison of electrical conductance of the AgNWs before and after reactive ion etching. (f) An optical microscopic image of patterned graphene-AgNW hybrid films by using dry and wet etching process. Scale bar is 10 μm. (g) Optical images of patterned hybrid films with various channel length after electrical breakdown. Scale bars are 10 μm. (h)I-V characteristics of AgNWs, graphene, and their hybrid channels (channel width: 10 μm, length: 50 μm). The lower graph is the magnification of the upper graph.
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Fig6: Patterning of AgNW networks and breakdown characteristics of the hybrid pattern. (a) An optical microscope image of patterned AgNW networks as channel by using dry etching. Top inset of (a) A schematic diagram of a device layout with patterned AgNW networks as channel. Scale bar is 30 μm. SEM images of AgNW networks (b) unexposed and (c) exposed to oxygen plasma. Scale bars are 5 μm. (d) A magnified SEM image of disconnected AgNW networks after dry etching process. Scale bar is 500 nm. (e) Comparison of electrical conductance of the AgNWs before and after reactive ion etching. (f) An optical microscopic image of patterned graphene-AgNW hybrid films by using dry and wet etching process. Scale bar is 10 μm. (g) Optical images of patterned hybrid films with various channel length after electrical breakdown. Scale bars are 10 μm. (h)I-V characteristics of AgNWs, graphene, and their hybrid channels (channel width: 10 μm, length: 50 μm). The lower graph is the magnification of the upper graph.

Mentions: The electrical conductance of the nanostructured films can be changed by pattern size, such as via the widths and lengths of a pattern [40]. For this study, the fabrication process began with the evaporation of metal contact pads of Cr/Au (2/300 nm) onto a 300-nm-thick SiO2 on Si wafer, and then graphene, AgNW networks, and their hybrid structures were formed on this substrate with metal pads, respectively. The patterning of the aforementioned three materials with various widths and lengths was performed by using photolithography and dry and wet etching processes, followed by measurement and comparison of their R (see Experimental methods). Figure 6a shows an optical microscope image of the patterned AgNW random networks with a channel length and width of 30 and 70 μm, respectively. The top inset of Figure 6a exhibits a schematic illustration of a device layout with patterned AgNW networks as a channel. Figure 6b,c presents SEM images of the AgNW networks which were unexposed and exposed to oxygen plasma, respectively. Here, it is important to note that AgNWs remained with slightly modified shapes after oxygen plasma exposure (red rectangular in Figure 6a,c). To inspect in detail, the magnified SEM image of AgNW networks affected from oxygen plasma was used as described in Figure 6d, and this SEM image presented disconnected, fattened, and oxidized AgNW residues after reactive ion etching (RIE). Figure 6e presents the electrical conductance of AgNW networks before and after exposure to oxygen plasma. As expected, the AgNW networks were electrically nonconductive after the RIE process. From these results, we confirmed that locally nonconductive areas of the AgNW network films can be made by using photolithographical patterning and a RIE process.Figure 6


Studies on the mechanical stretchability of transparent conductive film based on graphene-metal nanowire structures.

Lee MS, Kim J, Park J, Park JU - Nanoscale Res Lett (2015)

Patterning of AgNW networks and breakdown characteristics of the hybrid pattern. (a) An optical microscope image of patterned AgNW networks as channel by using dry etching. Top inset of (a) A schematic diagram of a device layout with patterned AgNW networks as channel. Scale bar is 30 μm. SEM images of AgNW networks (b) unexposed and (c) exposed to oxygen plasma. Scale bars are 5 μm. (d) A magnified SEM image of disconnected AgNW networks after dry etching process. Scale bar is 500 nm. (e) Comparison of electrical conductance of the AgNWs before and after reactive ion etching. (f) An optical microscopic image of patterned graphene-AgNW hybrid films by using dry and wet etching process. Scale bar is 10 μm. (g) Optical images of patterned hybrid films with various channel length after electrical breakdown. Scale bars are 10 μm. (h)I-V characteristics of AgNWs, graphene, and their hybrid channels (channel width: 10 μm, length: 50 μm). The lower graph is the magnification of the upper graph.
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Fig6: Patterning of AgNW networks and breakdown characteristics of the hybrid pattern. (a) An optical microscope image of patterned AgNW networks as channel by using dry etching. Top inset of (a) A schematic diagram of a device layout with patterned AgNW networks as channel. Scale bar is 30 μm. SEM images of AgNW networks (b) unexposed and (c) exposed to oxygen plasma. Scale bars are 5 μm. (d) A magnified SEM image of disconnected AgNW networks after dry etching process. Scale bar is 500 nm. (e) Comparison of electrical conductance of the AgNWs before and after reactive ion etching. (f) An optical microscopic image of patterned graphene-AgNW hybrid films by using dry and wet etching process. Scale bar is 10 μm. (g) Optical images of patterned hybrid films with various channel length after electrical breakdown. Scale bars are 10 μm. (h)I-V characteristics of AgNWs, graphene, and their hybrid channels (channel width: 10 μm, length: 50 μm). The lower graph is the magnification of the upper graph.
Mentions: The electrical conductance of the nanostructured films can be changed by pattern size, such as via the widths and lengths of a pattern [40]. For this study, the fabrication process began with the evaporation of metal contact pads of Cr/Au (2/300 nm) onto a 300-nm-thick SiO2 on Si wafer, and then graphene, AgNW networks, and their hybrid structures were formed on this substrate with metal pads, respectively. The patterning of the aforementioned three materials with various widths and lengths was performed by using photolithography and dry and wet etching processes, followed by measurement and comparison of their R (see Experimental methods). Figure 6a shows an optical microscope image of the patterned AgNW random networks with a channel length and width of 30 and 70 μm, respectively. The top inset of Figure 6a exhibits a schematic illustration of a device layout with patterned AgNW networks as a channel. Figure 6b,c presents SEM images of the AgNW networks which were unexposed and exposed to oxygen plasma, respectively. Here, it is important to note that AgNWs remained with slightly modified shapes after oxygen plasma exposure (red rectangular in Figure 6a,c). To inspect in detail, the magnified SEM image of AgNW networks affected from oxygen plasma was used as described in Figure 6d, and this SEM image presented disconnected, fattened, and oxidized AgNW residues after reactive ion etching (RIE). Figure 6e presents the electrical conductance of AgNW networks before and after exposure to oxygen plasma. As expected, the AgNW networks were electrically nonconductive after the RIE process. From these results, we confirmed that locally nonconductive areas of the AgNW network films can be made by using photolithographical patterning and a RIE process.Figure 6

Bottom Line: Transparent electrodes with superior flexibility and stretchability as well as good electrical and optical properties are required for applications in wearable electronics with comfort designs and high performances.High electrical and optical characteristics, superb bendability (folded in half), excellent stretchability (10,000 times in stretching cycles with 100% in tensile strain toward a uniaxial direction and 30% in tensile strain toward a multi-axial direction), strong robustness against electrical breakdown and thermal oxidation were obtained through comprehensive study.We believe that these results suggest a substantial promise application in future electronics.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Wearable Electronics Research Group, Low-Dimensional Carbon Materials Research Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798 Republic of Korea.

ABSTRACT
Transparent electrodes with superior flexibility and stretchability as well as good electrical and optical properties are required for applications in wearable electronics with comfort designs and high performances. Here, we present hybrid nanostructures as stretchable and transparent electrodes based on graphene and networks of metal nanowires, and investigate their optical, electrical, and mechanical properties. High electrical and optical characteristics, superb bendability (folded in half), excellent stretchability (10,000 times in stretching cycles with 100% in tensile strain toward a uniaxial direction and 30% in tensile strain toward a multi-axial direction), strong robustness against electrical breakdown and thermal oxidation were obtained through comprehensive study. We believe that these results suggest a substantial promise application in future electronics.

No MeSH data available.


Related in: MedlinePlus