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.

Dealloying has been widely employed lately for the fabrication of nanoporous metals. However, in case of thin films, the impact of the initial morphology on the final porosity is still not well understood. In this work, we report on the influence of the initial morphology of silver-aluminum (Ag-Al) thin films on the dealloying process in hydrochloric acid. The films deposition was performed by a DC co-sputtering process of silver and aluminum targets in a cofocal geometry using pure argon plasma; by tuning the deposition conditions such as the electrical powers applied to the targets and the deposition temperature, films with various compositions and morphologies can be obtained. The dealloying is then carried out using a free corrosion process applied in diluted (2 wt.%) hydrochloric acid in order to leach preferentially aluminum leaving behind a nanoporous skeleton of silver. We show that the dealloying process becomes faster when decreasing the initial silver content within the films. We further demonstrate that the dealloying kinetic is also dependent on the initial morphology of the Ag-Al films: it increases when decreasing the size of the columns forming the Ag-Al films.Top-view SEM image of Ag-Al alloy thin film with 23 at.% of initial Ag content dealloyed for 5 min in 2 wt.% hydrochloric acid.