Extremely Robust and Reliable Transparent Silver Nanowire‐Mesh Electrode with Multifunctional Optoelectronic Performance through Selective Laser Nanowelding for Flexible Smart Devices

Abstract

As the demand for foldable or rollable smart electronic devices increases, the issue of damage caused by cyclic fatigue of the flexible transparent electrode (FTE) due to repeated bending stress at extremely low bending radius is emerging. Herein, it is demonstrated that a mesh electrode composed of silver nanowires (Ag NW–mesh) with multifunctional optoelectronic performance microfabricated without photomasking via selective laser nanowelding (SLNW) followed by soft‐etching of highly ductile Ag NWs on a flexible polymer film exhibits long‐term cycling stability at bending stresses of a 1 mm radius of curvature (ROC). In the optimal NW microgrid pattern design, the cycle fatigue resistance of NW–mesh electrodes considerably increases with increase in NW areal mass density (AMD) and decreasing microgrid spacing due to the improved weldability and networkability of NWs at a low laser energy density of 1 J cm−2. A diagonally gridded NW–mesh electrode with 30 μm line spacing exhibits extremely high reliability with little change in the performance of Joule heating and electromagnetic interference shielding under long‐term bending stresses of 300 000 cycles at 1 mm ROC. Being a simple process without photomasking, this method can easily use a multifunctional FTE with ultrahigh fatigue resistance and reliability suitable for highly flexible smart devices.

Patterning of Metal Nanowire Networks: Methods and Applications

“…(e) Optoelectronic property of Ag NW meshes with various line spacings. Reproduced with permission from ref . Copyright 2021 Wiley.…”

“…Thus, desired patterns can be obtained through laser sintering, as MNWN can be selectively laser sintered on a substrate, and the nonsintered MNWs can be removed by proper solvents (Figure c). AgNW mesh with different line widths and line spacing can be fabricated (Figure c,d), and the optoelectronic properties of the mesh can be adjusted by changing the line spacing (Figure e) . Furthermore, AgNW diagonal mesh electrodes showed almost no damage to the electrode after 300 000 bending cycles at a 1 mm radius of curvature.…”

“…AgNW mesh with different line widths and line spacing can be fabricated (Figure 5c,d), and the optoelectronic properties of the mesh can be adjusted by changing the line spacing (Figure 5e). 97 Furthermore, AgNW diagonal mesh electrodes showed almost no damage to the electrode after 300 000 bending cycles at a 1 mm radius of curvature.…”

Biocompatible, Flexible, and High-Performance Nanowelded Silver Nanowires on Silk Fibroin for Transparent Conducting Electrodes toward Biomemristor Application

“…Wu and co-authors reduced the wire-to-wire junction resistance using mechanical pressing, which is not suitable for most of the ultra-smooth, flexible, and conformable substrates owing to their complex mechanical forces applied on the substrates, which might result in the formation of a number of microcracks . The nanojoining techniques using sophisticated laser treatment and beam irradiation are not only expensive but also sometimes might damage the polymeric flexible substrates. − One way to mitigate the issue is by using the laser technology, which is cost effective and has low power beam irradiation, thereby minimizing the damage to most of the polymeric flexible substrates. Hence, there is a need for the development of novel, simple, facile, and cost- and energy-effective solutions, which can be easily adopted for all the flexible substrates without any further complexities.…”

Effective terahertz shielding properties of extreme graphene-silver nanowire surfaces investigated by nanoprobing

“…These unique characteristics enable silver nanowires to substitute bulk silver films, maintaining the merit of the nanostructure with high surface-to-volume ratio. Moreover, additional methods can further increase shielding efficiency (SE), including high-temperature sintering ( Choi et al., 2019a ; Gu et al., 2020 ), mechanical pressing ( Li et al., 2021 ; Yang et al., 2021 ), light-induced welding ( Kim et al., 2021 ), and composites with other materials ( Chen et al., 2020 ; Hu et al., 2012 ; Jia et al., 2021 ; Wan et al., 2018 ; Zhou et al., 2020 ). However, their mechanism for preventing signal interference is not yet fully understood owing to the huge scale mismatch between the relatively long wavelength (micrometer to centimeter) and the flake size (mostly nanoscale).…”