A highly flexible transparent conductive electrode based on nanomaterials

Abstract

The electrical, optical, thermal, chemical, mechanical and tribological characteristics of a highly flexible transparent conductive electrode (HFTCE) coating based on reduced graphene oxide (rGO), carbon nanotubes (CNTs) and silver nanowires (AgNWs) were investigated under various conditions. The motivation was to develop a highly durable and flexible film for transparent conductive electrode applications. The overall characteristics of multilayers based on rGO, CNTs and AgNWs were found to be much better than those of the single-layer AgNW coating. The rGO and CNT layers served to protect the AgNW layer from damage due to bending and contact sliding motions. The contact pressure and bending stress were effectively distributed by the CNT layer deposited on top of the AgNW layer due to its spring-like behavior. In addition, the shear force from the friction force was reduced by the rGO top layer, which acted as a solid lubricant. Furthermore, the excellent performance of an HFTCE heater based on the rGO/CNT/AgNW coating was demonstrated by the results of a defrosting test. NPG Asia Materials (2017) 9, e438; doi:10.1038/am.2017.177; published online 13 October 2017 INTRODUCTIONIn recent decades, various transparent conductive films electrodes have been widely used in electronic devices such as solar cells, displays, memories and batteries. 1 In particular, indium tin oxide (ITO) has attracted considerable attention as a transparent conductive electrode because of its excellent optical and electrical properties. 2 However, indium, which is the main raw material used in ITO, has some disadvantages in terms of production and cost. Moreover, ITO application in flexible devices is limited by its brittleness. 3 To replace ITO in flexible devices, several types of conductive polymers, such as poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) and poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric acid methyl ester have been suggested. 4,5 However, the electrical efficiency of these conductive polymers is much lower than that of ITO. Moreover, the mechanical properties of these conductive polymers are very weak despite their flexibility. Therefore, it is necessary to combine these conductive polymers with other electrodes to improve efficiency.Many studies using other types of conductive materials, such as graphene and carbon nanotubes (CNTs), have been conducted. [6][7][8][9][10][11][12] While carbon-based nanosheets and nanowires are known as materials with excellent mechanical and electrical properties, the sheet resistance of the coatings based on carbon is higher. Li et al. 6 demonstrated that the number of graphene layers deposited on the surface had a significant effect on their conductivity and transmittance. They found

Corrosion-Induced Mass Loss Measurement under Strain Conditions through Gr/AgNW-Based, Fe-C Coated LPFG Sensors

“…Therefore, a transparent conductive film (TCF) is needed in the process of Fe-C electroplating to improve the sensitivity and service life of the LPFG sensor. In the past decades, TCF has received increasing attention in applications such as sensors, actuators, optical devices and touchscreens [16,17]. The most commonly used TCF in these industries was a Indium Tin Oxide (ITO) film, which is optically transparent in the visible light range and electrically conductive [18,19].…”

“…It was originally produced from graphite in laboratory through mechanical exfoliation [21][22][23]. Due to its excellent optical, electrical, mechanical and thermal properties, graphene was used as a TCF in many applications such as flexible touchscreen, organic light emitting diode (OLED), chemical sensor, soft robotics, actuators and biological devices [16,17,[24][25][26]. In order to achieve industry-scale productions, various graphene synthesis techniques were developed by researchers [27][28][29][30].…”

Facile synthesis of battery waste-derived graphene for transparent and conductive film application by an electrochemical exfoliation method

“…On the other hand, the fast-growing and large-volume-need of transparent conductive electrode by touch screens, LCDs, OLEDs and solar cells demands supplement or even replacement for their traditional material, ITO (indium tin oxide), which is brittle and costly in production thus unsuitable for emerging applications requiring exibility. 21 Graphene can be a great choice as the substituent, thanks to its low density, robustness, mechanical exibility, chemical stability, as well as potentially being produced at low cost. 22,23 Compared to ITO, it also has a atter transmittance spectra in the visible and infrared range, highly desirable for solar cell and display applications.…”

A synergetic layered inorganic–organic hybrid film for conductive, flexible, and transparent electrodes

“…However, these materials do not outmatch ITO, in terms of initial conductivity and environmental stability. [10][11][12][13][14][15][16] Currently, high-quality ITO films are prepared using a great variety of deposition techniques including, but not limited to, vacuum evaporation, magnetron sputtering (DC and RF), molecular beam epitaxy, pulsed laser deposition, chemical vapor deposition, spray pyrolysis, sol-gel reaction, etc. 17 Due to its superior controllability, high uniformity over large area substrates and high deposition rate, magnetron sputtering is the most widely used technique for thin film deposition.…”

“…Using flexible polymer substrates is only possible at low temperatures. 12 Current trends in flexible electronics also raise the issue of brittle behavior for polycrystalline ITO films and its derivatives (InZnO, InZnAlO, InGaZnO, InZnSnO, etc. ), which restricts their applications, in spite of their high transparency and low resistivity.…”