High-Performance Transparent and Conductive Films with Fully Enclosed Metal Mesh

Abstract

Metal mesh films as a kind of transparent conductive electrodes (TCEs) have shown high promise in various optoelectronic devices but are still challenged by a combination of high conductivity and transparency, mechanical robustness, and uniform electric field. Herein, we demonstrate a new concept of transparent and conductive films with a fully enclosed metal mesh, which is embedded in deep microcavities and is coated with a conductive polymer layer to combine these metrics. To ensure high conductivity and transparency, metal ink is filled into the fine (down to submicrometers) and deep mesh microcavities by electrowetting-assisted blading with low square resistances of 0.4 and 2.69 Ω sq–1 at typical transmittances of 76.9 and 87.4%, respectively. The covered thin conductive polymer layer improves the electric field uniformity of metal mesh films by at least three orders of magnitude. The fully enclosed metal mesh films exhibit excellent mechanical flexibility, indicated by the fact that the resistance is almost unchanged after 10,000 bending cycles at a bending radius of ∼5 mm. Based on the fully enclosed metal mesh films, the emission intensity of alternating current electroluminescent devices is improved by more than three times compared with that in the case of solely using common metal mesh films.

Printed Copper Grid Transparent Conducting Electrodes for Organic Light-Emitting Diodes

“…The conventional fabrication process of a metal grid is vacuum deposition and photolithographic patterning, − creating challenges for low-cost high-throughput supply. A technologically more attractive deposition method is high-resolution printing which allows line widths of a few micrometers or even sub-micrometers. − Additive printing technologies have great potential for scalability and high productivity by roll-to-roll manufacturing, are compatible with low-temperature plastic substrates, and show low environmental load in production. Furthermore, the choice for copper as grid material would make TCEs cheaper than those based on gold or silver, still with the potential to outperform ITO.…”

Self‐Encapsulated Cu Grid for Highly Transparent Conductive Electrode for Transparent Heater and Electrochemical Supercapacitor Applications

“…Nie et al developed an Ag-based metal mesh enclosed by polymer-based PEDOT:PSS with lower sheet resistance of 2.96 Ω □ −1 , but with lower transmittance of 87.4%, showing that the enclosed hybrid electrode struggles with lower transmittance. [21] Thus the effective solution to develop a low sheet resistance with higher transparency electrode has not previously been established.…”

All-atmospheric fabrication of Ag–Cu core–shell nanowire transparent electrodes with Haacke figure of merit >600 × 10–3 Ω−1

“…High-performance metal nanowire TCEs contain low-resistivity wires with uniform distribution and fused junctions to reduce contact resistances. There are various nanowire patterning techniques, including polymer imprinting 22 – 25 , electrohydrodynamic printing 26 , 27 , solution processing 28 , 29 , cracked film lithography 30 , and electrospinning 31 – 36 . Polymer imprinting and electrospinning are two of the most common patterning methods due to their scalability and low cost.…”