Customizable Stretchable Transparent Electrodes Based on AgNW/CNT Hybrids via Tailoring Sizes of Building Blocks

Abstract

Stretchable transparent electrodes (STEs) based on silver nanowires (AgNWs) have received considerable attention for a variety of flexible and wearable electronic/optoelectronic devices. Up to now, most efforts have focused on optimizing the STEs composed by a single AgNW conductive network. On the contrary, the structure−performance correlations of STEs formed by a hybrid percolative network which comprises the AgNW and a second conductive nanomaterial have rarely been discussed. In this work, we fabricated hybrid-type STEs by selecting three kinds of carbon nanotubes (CNTs) with different diameters to pair with three types of AgNWs with variable length-to-diameter ratios. The size effect of building blocks of the nine combinations on the optical, electrical, and mechanical properties of resultant STEs was thoroughly investigated. The results reveal that AgNWs and CNTs with smaller diameters are beneficial to achieve hybrid electrodes with a high transmittance and low haze. AgNWs with larger length-to-diameter ratios contribute hybrid STEs with lower sheet resistance by adding a suitable amount of CNTs. Importantly, the smaller differences in diameters of AgNWs and CNTs lead to more effective capillary-force-induced welding, which boosts both the conductivity and stretchability of STEs. An optimized AgNW/CNT hybrid electrode demonstrated a transmittance of 66.4% and a haze of 11.0% at a sheet resistance of 8.70 Ω sq. −1 which could endure a uniaxial tensile strain as large as 490%, while its resistance increased only 46.9% after experiencing 1000 cycles of 50% tensile strain. Alternating current electroluminescent devices based on such AgNW/ CNT hybrid STEs were also successfully developed, showing uniform and stable patterned luminescence.

Origin of Capillary-Force-Induced Welding in Ag Nanowires and Ag Nanowire/Carbon Nanotube Conductive Networks

“…Meanwhile, the average thicknesses of AgNW-28/CNT-5, AgNW-28/CNT-7.7, and AgNW-28/CNT-10 hybrid films were 1.41, 2.85, and 3.69 μm, respectively (Figure S6), which means that large-radius nanobuilding blocks (AgNWs and CNTs) can effectively obtain high-thickness conductive films. Further addition of CNTs to 2.0 × 10 9 cm –2 caused a slight increase in the R s of AgNW-28/CNT-10 and AgNW-28/CNT-7.7, which should be ascribed to the aggregation of redundant CNTs (mass increase per unit area) and their intrinsically low conductivity compared to AgNWs. , Apparently, the incorporation of larger-radius CNT-10 always results in a greater reduction in R s after welding (Figure b). The SEM images in Figure S5i–l prove that both AgNW–AgNW junctions and AgNW–CNT junctions can be welded together with the help of capillary force.…”

“…Further addition of CNTs to 2.0 × 10 9 cm −2 caused a slight increase in the R s of AgNW-28/CNT-10 and AgNW-28/CNT-7.7, which should be ascribed to the aggregation of redundant CNTs (mass increase per unit area) and their intrinsically low conductivity compared to AgNWs. 18,26 Apparently, the incorporation of larger-radius CNT-10 always results in a greater reduction in R s after welding (Figure 4b). The SEM images in Figure S5i−l prove that both AgNW−AgNW junctions and AgNW−CNT junctions can be welded together with the help of capillary force.…”

“…Moreover, it is still difficult to figure out the capillary force between two spheres of different diameters using the existing model. On the other hand, significant progress has been made over the past few years in developing high-performance transparent flexible electrodes by combining AgNWs with other conductive materials (such as carbon nanotubes (CNTs)). ,− Extending the theoretical capillary-force model to different nanomaterials and studying the resulting capillary force can improve the performance of hybrid electrodes.…”

Synthesis, Sorting, and Applications of Single-Chirality Single-Walled Carbon Nanotubes

“…It has been also reported that a hybrid structure, such as a combination of AgNWs and CNTs, exhibits superior behavior as transparent electrodes [ 161 , 161 , 162 , 163 , 164 , 165 ]. In particular, CNT can form conductive bridges between the AgNWs, which enhance the conductivity.…”

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree‐like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers

“…On one hand, the growth of BNNS on the surface of AgNWs needs strong force to maintain the stability of the composite system due to the large aspect ratio and high surface curvature of AgNWs. [46][47][48] On the other hand, it is challenging to precisely control the optimal morphology of heterostructured AgNWs@BNNS thermally conductive fillers because there is no reported technology for orientation or uniform distribution that can be utilized as guidance. [49][50][51] The advantages of aramid nanofibers (ANF) include lightweight, high specific strength, and good high-temperature resistance, [52,53] as well as its ability to maintain outstanding mechanical and electrical insulating properties in situations with both high and low temperature and humidity.…”