Continuous Patterning of Copper Nanowire-Based Transparent Conducting Electrodes for Use in Flexible Electronic Applications

Abstract

Simple, low-cost and scalable patterning methods for Cu nanowire (NW)-based flexible transparent conducting electrodes (FTCEs) are essential for the widespread use of Cu NW FTCEs in numerous flexible optoelectronic devices, wearable devices, and electronic skins. In this paper, continuous patterning for Cu NW FTCEs via a combination of selective intense pulsed light (IPL) and roll-to-roll (R2R) wiping process was explored. The development of continuous R2R patterning could be achieved because there was significant difference in adhesion properties between NWs and substrates depending on whether Cu NW coated area was irradiated by IPL or not. Using a custom-built, R2R-based wiping apparatus, it was confirmed that nonirradiated NWs could be clearly removed out without any damage on irradiated NWs strongly adhered to the substrate, resulting in continuous production of low-cost Cu NW FTCE patterns. In addition, the variations in microscale pattern size by varying IPL process parameters/the mask aperture sizes were investigated, and possible factors affecting on developed pattern size were meticulously examined. Finally, the successful implementation of the patterned Cu NW FTCEs into a phosphorescent organic light-emitting diode (PhOLED) and a flexible transparent conductive heater (TCH) were demonstrated, verifying the applicability of the patterned FTCEs. It is believed that our study is the key step toward realizing the practical use of NW FTCEs in various flexible electronic devices.

Printable High‐Aspect Ratio and High‐Resolution Cu Grid Flexible Transparent Conductive Film with Figure of Merit over 80 000

“…The transmittance of fully filled Cu metal-mesh including polyethylene terephthalate (PET) substrate is about 88.1% while 90% for only a Ag seed layer. [14,18,29] Although Cu metal-mesh TCF has a reddish color, which has some disadvantages for practical device applications, a thin nickel layer of about 10-20 nm on top of copper would be electroplated to eliminate the reddish color, as shown in Figure S11 (Supporting Information). In parallel, sheet resistance from only a seed layer to fully filling Cu in the microgrooves varied from 50.8 to 0.29 Ω □ −1 .…”

Emerging Novel Metal Electrodes for Photovoltaic Applications

“…By using the photomask, patterned metal nanowire transparent electrode can also be achieved through direct exposure by high pulse laser, contributed by the photothermal effect. Under the irradiation of pulse laser with proper power, the metal NWs will be welded together and gradually embedded into the polymer substrate, while the metal NWs without light irradiation can easily be removed by solvent or tape due to the poor bonding between nanowire and polymer substrate . On the other hand, ablation of metal NWs will happen when the power of pulse laser is high enough.…”

Copper nanomaterials and assemblies for soft electronics

“…Doctor blade coating is a conventional thin film deposition technique, in which a sharp blade moves over the Cu inks on a substrate, leaving a thin film of Cu composites with a uniform thickness, which is controlled by the gap distance between the blade and the substrate [49,105]. Doctor blades can be replaced by Mayer rods, i.e., periodical grooved rods or wire-wound rods, to control the thickness of thin films by the groove or wire geometries [81,106,107]. Inks are squeezed through the empty spaces from the grooves or wires to form uniform thin films.…”