Uniform, highly conductive, and patterned transparent films of a percolating silver nanowire network on rigid and flexible substrates using a dry transfer technique

Abstract

Silver nanowire films are promising alternatives to tin-doped indium oxide (ITO) films as transparent conductive electrodes. In this paper, we report the use of vacuum filtration and a polydimethylsiloxane (PDMS)-assisted transfer printing technique to fabricate silver nanowire films on both rigid and flexible substrates, bringing advantages such as the capability of patterned transfer, the best performance among various ITO alternatives (10 Ω/sq at 85% transparency), and good adhesion to the underlying substrate, thus eliminating the previously reported adhesion problem. In addition, our method also allows the preparation of high quality patterned films of silver nanowires with different line widths and shapes in a matter of few minutes, making it a scalable process. Furthermore, use of an anodized aluminum oxide (AAO) membrane in the transfer process allows annealing of nanowire films at moderately high temperature to obtain films with extremely high conductivity and good transparency. Using this transfer technique, we obtained silver nanowire films on a flexible polyethylene terephthalate (PET) substrate with a transparency of 85%, a sheet resistance of 10 Ω/sq, with good mechanical flexibility. Detailed analysis revealed that the Ag nanowire network exhibits two-dimensional percolation behavior with good agreement between experimentally observed and theoretically predicted values of critical volume.

Facile fabrication of stretchable Ag nanowire/polyurethane electrodes using high intensity pulsed light

“…One challenge for simple and effective assembly of nanowire networks is the removal of the insulating PVP surfactant coating from the NWs after deposition to ensure conductivity through wire-wire junctions. This is usually done through treatments such as thermal annealing [39][40][41][42] or mechanical pressing [39,40,43]. However, thermal annealing (often over 150 °C ) is very time consuming (from minutes to hours) and excludes the use of many heat-sensitive materials, while pressing techniques can cause damage to delicate substrates or devices.…”

“…Another challenge in the implementation of a nanowire network is obtaining strong adhesion between the network and the substrate for stable and robust performance. To successfully improve the adhesion, substrate surface modification has been used [40,41,44], a strong conformal pressure has been applied [40,43], and in-situ polymerization [45,46] and surface encapsulation have been reported [26,27,41,42,47]. However, these processes are complex and time-consuming, in addition to the fact that they may change the properties of the substrate materials.…”

Effective Electrode Length Enhances Electrical Activation of Nanowire Networks: Experiment and Simulation

“…1,2 Currently, metallic nanowire networks are being investigated as next-generation transparent conductors, 3,4 artificial skins, [5][6][7] and flexible optoelectronic devices. [8][9][10] However, to build reliable materials and devices, it is necessary to be able to tune the sheet resistance, and hence the connectivity between the wires that comprise these networks.…”

Nanomaterial-based stretchable and transparent electrodes

“…In addition, the random network of AgNWs has shown outstanding mechanical deformability, such as flexibility and stretchability, originating from its inherent percolation structure, with excellent thermal and chemical stability [12,13]. The fabrication of AgNW-based stretchable and transparent electrodes has been achieved through various solution processes, including Meyer rod coating, filtration, spin coating, and Resistance increased by ∼ 440% (ε = 100%) [90] spray coating, which are desirable compared to the vacuum evaporation processes in terms of process cost and scalability [14][15][16][17].…”