Printable Silver Nanowire and PEDOT:PSS Nanocomposite Ink for Flexible Transparent Conducting Applications

Abstract

Patterned deposition of highly flexible transparent conducting materials is essential to realize stretchable optoelectronic devices. Silver nanowires (NWs) are suitable for these applications because they possess high electrical conductivity and good optical transparency. However, NWs have poor surface adhesion and large roughness. Embedding them in a conducting polymer, such as poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PE-DOT:PSS), is one way to overcome these disadvantages without affecting the optoelectronic properties. However, this is normally a two-step deposition process and difficult to pattern directly. In this work, we have formulated a stable and printable nanocomposite ink consisting of Ag NWs and PEDOT:PSS. This ink can be directly used for patterned deposition in a single-step process. The printed film shows 86% transparency and 23 Ω/sq sheet resistance, which is suitable for flexible transparent electrode applications. The printed film shows good adhesion and excellent stability to mechanical deformation, with less than 20% resistance variation after 10,000 bending cycles. The nanocomposite also exhibits improved thermal stability, planarity, reduced contact resistance, and good optical transparency when compared to pure Ag NWs. We demonstrate suitability of this nanocomposite using two applications −a printed transparent flexible antenna radiating at Wi-Fi frequencies and a printed transparent flexible heater suitable for antifogging applications. The nanocomposite properties make it suitable as a transparent electrode in flexible optoelectronic devices such as photovoltaics and light-emitting diodes.

Recent progress on PEDOT:PSS based polymer blends and composites for flexible electronics and thermoelectric devices

“…materials. 51,52 A thin layer, 53 wavy pattern, 54-57 buckled [58][59][60][61] and wrinkled [62][63][64][65] conductive polymer network is deposited on the surface of an elastomer or constructed inside an elastic substrate to convert the overall tensile strain into local bending strain. However, the failure of electronic devices with such a multilayer structure mostly originates from the debonding between different layers because of poor interfacial interactions and large mechanical mismatch.…”

Ultrathin-shell epitaxial Ag@Au core-shell nanowires for high-performance and chemically-stable electronic, optical, and mechanical devices

“…The performance stands out in comparison with other published work on different materials candidates for flexible electrodes (Fig. 4(c)), such as AgNW [59], copper nanowire [59], carbon nanotube (CNT) [60], graphene [59], and PEDOT [24,61], that demonstrate 17.3 Ω/sq at 91%, 62.5 Ω/sq at 90%, 71.05 Ω/sq at 92%, 87.5 Ω/sq at 93%, and 100 Ω/sq at 91%, respectively. In particular, the Ag@Au core-shell NW transparent electrodes have demonstrated performance comparable to commercial indium tin oxide (ITO) performance (21 Ω/sq at 90% [62]) and pristine AgNW [59] (17.3 Ω/sq at 91%), which is so far the best candidate for flexible transparent electrodes.…”

“…Therefore, there has been an ongoing drive to develop strategies for the effective oxidation protection of AgNWs without impairing their inherent electrical, optical, and mechanical properties, preferably through low-cost solution-phase processes to be compatible with large-scale industrial device fabrication. So far, approaches reported to address the long-term stability of AgNWs could be summarized into two major categories: (1) For devices fabricated with AgNW networks, a polymer or ceramic overlayer is coated on the AgNW networks predeposited on a substrate as a corrosion barrier, such as polydimethylsiloxane (PDMS) [18][19][20][21], poly (methyl methacrylate) (PMMA) [22,23], poly (3,4-ethylenedioxythio-phene): poly(styrene sulfonate) (PEDOT: PSS) [24][25][26][27], reduced graphene oxide (rGO) [28][29][30] and atomic-layer-deposited aluminumdoped zinc oxide (AZO) and aluminum oxide (Al2O3) [2,31,32];…”

Spatial Resolution and Capacitive Coupling in the Characterization of Nanowire Nanocomposites by Scanning Dielectric Microscopy

“…Applications of these novel materials include transparent electrodes for solar cell applications (Yu et al, 2011; Zhang & Engholm, 2018), flexible electrodes for wearable electronics (Langley et al, 2013; Li et al, 2020), and high dielectric constant or conductive stretchable materials for pressure and motion sensors (Wang et al, 2015; Jing et al, 2019). Nanowire nanocomposite materials offer, in addition, the advantage of being solution processable (Gaynor et al, 2010; Zeng et al, 2010) or printable (Nair et al, 2020; Wu et al, 2020).…”