Vapor dealloying of ultra-thin films: a promising concept for the fabrication of highly flexible transparent conductive metal nanomesh electrodes

Abstract

The booming market of flexible electronic displays has urged the development of highly flexible transparent conductive electrodes (FTCE) 1-3 with the ability to replace indium tin oxide (ITO) thin films routinely used as transparent conductive electrodes in photoelectronic devices. The high cost of indium and the poor mechanical stability of ITO under deformation are the main driving forces behind the development of this research area. 4 The use of metal nanomeshes as FTCE is a promising concept with a real potential to substitute ITO in photoelectronic devices. 5,6 However, the development of a low-cost fabrication approach allowing producing metal nanomesh electrodes with competitive prices and a high performance remains a real bottleneck for the photoelectronic industry. In this paper, we report on a robust approach very easy to implement allowing producing highly flexible metal nanomesh electrodes with high performance at a very low cost. This approach lies on a concept consisting in applying dealloying process to ultra-thin Au-Cu alloy thin films using acidic vapors instead of a liquid phase as routinely done in the literature. Using an appropriate procedure, the nanomeshes can be transferred to any planar or curved support where they can serve as a FTCE. As a proof of concept, we demonstrate that using this approach, one can easily fabricate gold nanomesh electrodes transferred onto polyethylene terephthalate (PET) film surface with 79% of transmittance and a sheet resistance as low as 44 Ω □ −1 while maintaining exceptional stability under severe mechanical deformations.

Study of the Coarsening of Nanoporous Gold Nanowires by In Situ Scanning Transmission Electron Microscopy During Annealing

“…Herein, for the first time, an experimental demonstration is carried out for the two different behaviors of morphology evolution with temperature, corresponding to ligament pinch-off and collapsing of nanoporous materials, which have been highlighted by simulations in the literature.Since a few years, nanoporous gold (NPG) has been pointed out as a promising candidate for various applications such as plasmonic sensors, [1] actuators, [2,3] catalysts, [4] super-capacitors, [5] and transparent flexible conductor. [6] The remarkable properties of NPG originate from a high specific surface area of NPG, characterized by the interconnected ligament structure at the nanoscale. [7] A crucial issue for the use of NPG in such applications is the control of both pore and ligament size.…”

“…Since a few years, nanoporous gold (NPG) has been pointed out as a promising candidate for various applications such as plasmonic sensors, actuators, catalysts, super‐capacitors, and transparent flexible conductor . The remarkable properties of NPG originate from a high specific surface area of NPG, characterized by the interconnected ligament structure at the nanoscale .…”

The wrinkling concept applied to plasma‐deposited polymer‐like thin films: A promising method for the fabrication of flexible electrodes

“…[ 28 ] With regard to the evaluation of the electrical resistance of the Al/PPF bilayer system deposited on the PET substrate, bending tests were carried out using a homemade setup. [ 29 ] In this study, repeated bending deformations (i.e., 1,000 times) were applied. The electrical sheet resistance was measured after each deformation cycle using a two‐probe method.…”

Influence of Co-Sputtered Ag:Al Ultra-Thin Layers in Transparent V2O5/Ag:Al/AZO Hole-Selective Electrodes for Silicon Solar Cells

“…However due to its high-temperature processing, brittle nature, increasing cost due to the scarcity of indium and disadvantages in the terms of production [12,13], a continuous effort is being done in order to find suitable indium-free alternatives to ITO. Metallic nanowire networks, carbon nanotubes, conductive polymers, graphene, and ultra-thin metallic films [14][15][16][17][18] are some of the alternatives to potentially reduce the production cost in the photovoltaic (PV) industry. Recently, dielectric-metal-dielectric (DMD) structures have emerged as valid candidates to substitute the ITO electrode in silicon solar cells.…”