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

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.