Embedding Silver Nanowires into a Hydroxypropyl Methyl Cellulose Film for Flexible Electrochromic Devices with High Electromechanical Stability

Abstract

Transparent conductive films (TCFs) based on silver nanowires (AgNWs) are becoming one of the best candidates in realizing flexible optoelectronic devices. The AgNW-based TCF is usually prepared by coating AgNWs on a transparent polymer film; however, the coated AgNWs easily detach from the polymer underneath because of the weak adhesion between them. Herein, a network of AgNWs is embedded in the transparent hydroxypropyl methyl cellulose film, which has a strong adhesion with the AgNWs. The obtained TCF shows high optical transmittance (>85%), low roughness (rms = 4.8 ± 0.5 nm), and low haze (<0.2%). More importantly, owing to the embedding structure and strong adhesion, this TCF also shows excellent electromechanical stability, which is superior to the reported ones. Employing this TCF in a flexible electrochromic device, the obtained device exhibits excellent cyclic electromechanical stability and high coloring efficiency. Our work demonstrates a promising TCF with superior electromechanical stability for future applications in flexible optoelectronics.

Lightweight and High Mechanical Strength Silver Nanowire/Hydroxypropyl Methylcellulose Electromagnetic Interference Shielding Composite

“…Similar to building materials, Ag NWs can be regarded as “rebar”, while HPMC is relative to the “cement” in the aerogel structure. Also, in HPMC, there are abundant hydroxyl groups, which can strongly interact with AgNWs via chemical bonding and/or physical adsorbing . It suggests that the coordination bonds can form between silver atoms and the hydroxyl groups in HPMC by FT-IR measurement .…”

“…HPMC is an industrial product with excellent wettability and dispersibility. It is widely used in petrochemical building materials and other fields, such as dispersion and improved stability for Ag NWs. In addition, the mechanical properties of EMI shielding materials should meet engineering standards for practical applications .…”

Recent advances of metal nanowire based transparent conductive electrodes for flexible chromatic devices

“…Other noteworthy examples used newly developed metal NW electrodes. Very recently, Huang and co-workers reported a robust electrode by embedding Ag NWs networks in a polymer lm, which showed high transparency (>85%), low haze (<0.2%) and smooth surface (Li et al 2020a). In addition, the Ag NW network electrodes showed high electromechanical stability and good structural integrity due to the embedment of the NWs.…”

High-Performance Flexible Transparent Electrodes Fabricated via Laser Nano-Welding of Silver Nanowires

“…Moreover, the excellent optical transmittance would replace indium tin oxide (ITO) for next-generation, highly flexible optoelectronic applications, overcoming the drawbacks of time-consuming synthesis, indium requirement, and fragility during stretching and bending. In recent decades, numerous efforts have been made to develop alternative FTEs, including graphene [6][7][8], nanowires [9][10][11][12], carbon nanotubes (CNTs) [13][14][15], and PEDOT:PSS [16][17][18].…”

“…Therefore, a nano-welding technique for junction-localized energy confinement that will not deteriorate the substrate is still lacking. In addition, the adhesion of Ag-NW networks to the organic substrate also needs to be resolved by jointing Ag-NWs with the substrate gently [9,10].…”