(180p) Flexible transparent electrodes based on high-crystalline metallic nanowire networks

There have been large demands for flexible transparent conducting electrodes (TCEs) for the application towards various electronic devices. At this moment, indium tin oxide (ITO) withexcellent optical and electrical properties have been widely employed as the TCE materials but its application towards flexible TCEs is limited because of the mechanical brittleness of ITO. That is, the ITO can be easily cracked under bending, leading to increased demand to replace ITO with novel TCE materials. In this context, networks of silver nanowires (Ag NWs) have been considered as a cost-effective alternative in the flexible devices because of mechanical sustainability and good optical transparency of Ag NW-based conductors.

However, the practical and commercial application of Ag NW networks based TCEs are limited because Ag NW based flexible conductor has insufficient electro-optical property or mechano-electrical properties. More specifically, such insufficient mechano-electrical conductivity of Ag NW network-based devices can be attributable to the inherent junction resistance associated with charge transport between randomly oriented nanowires. Despite several approaches to address aforementioned issues through the junction welding, composite with conducting polymer or conductive materials, it is still required to devise novel Ag NW based conductive materials for flexible TCE applications.

In this presentation, we present A flexible transparent electrode based on a high-crystalline silver nanowire (Ag NW) network was fabricated. The fabricated flexible transparent electrode presents improved mechanical-electrical sustainability based on bending fatigue studies of silver nanowire (c-Ag NW) networks with improved crystallinity and application to patterned electrode-based electronic devices. The mechanical-electrical stability of nanowire network films is highly related to the density of defects or dislocations caused by externally applied crystal structural modifications. The c-Ag NWs network films prepared by solution-based heat treatment exhibit improved crystallinity and reduced dislocation density. During the application of 200,000 cycles of bending fatigue test (strain: 6.7%, bending radius: 1 mm), the c-Ag NWs network film showed a much reduced resistance change (ΔR/ΔRo: 241%) compared to the typical silver nanowire film (ΔR/ΔRo: 241%). 45%). When a 6 μm neck diamond electrode pattern is applied to the patterned electrode with the c-Ag NW network, it shows similar electrical properties (9.41 kΩ) to the ITO-based electrode (8.01 kΩ) despite the reduction in the number of nanowires.