Advances in Flexible Metallic Transparent Electrodes

Abstract

Transparent electrodes (TEs) are pivotal components in many modern devices such as solar cells, light‐emitting diodes, touch screens, wearable electronic devices, smart windows, and transparent heaters. Recently, the high demand for flexibility and low cost in TEs requires a new class of transparent conductive materials (TCMs), serving as substitutes for the conventional indium tin oxide (ITO). So far, ITO has been the most used TCM despite its brittleness and high cost. Among the different emerging alternative materials to ITO, metallic nanomaterials have received much interest due to their remarkable optical‐electrical properties, low cost, ease of manufacturing, flexibility, and widespread applicability. These involve metal grids, thin oxide/metal/oxide multilayers, metal nanowire percolating networks, or nanocomposites based on metallic nanostructures. In this review, a comparison between TCMs based on metallic nanomaterials and other TCM technologies is discussed. Next, the different types of metal‐based TCMs developed so far and the fabrication technologies used are presented. Then, the challenges that these TCMs face toward integration in functional devices are discussed. Finally, the various fields in which metal‐based TCMs have been successfully applied, as well as emerging and potential applications, are summarized.

A crack templated copper network film as a transparent conductive film and its application in organic light-emitting diode

“…Figure 6 shows the performances comparation of the flexible copper network TCFs. Transmittance at the wavelength of 550 nm and the sheet resistance values are plotted, in order to compare with the result of previous studies (metallic nanowire 13 , 44 – 46 metallic network 9 , 25 , 33 , 47 , hybrid 48 – 50 ). Figure of merit (FoM) were calculated, the calculation formula is as follows 51 where is the electrical conductance and is the optical conductance 51 , R s means sheet resistance and T denotes transmittance.…”

“…Figure 6 shows the performances comparation of the flexible copper network TCFs. Transmittance at the wavelength of 550 nm and the sheet resistance values are plotted, in order to compare with the result of previous studies (metallic nanowire 13,[44][45][46] metallic network 9,25,33,47 , hybrid [48][49][50] ). Figure of merit (FoM) were calculated, the calculation formula is as follows 51 13,[44][45][46] , metallic network 9,25,33,47 , hybrid [48][49][50]…”

“…These transparent conductive films (TCFs) can be mainly divide into three categories. Carbon-based TCFs (graphene 3 , carbon nanotubes (CNTs) 4 ); metal based TCFs (metallic nanowires 5 , 6 and metallic network 7 – 9 ) and hybrid TCFs 10 – 12 .…”

“…Amit Kumar and co-workers systematically elaborate an abundant of approaches to forming silver nanowire for fabricating transparent conducting electrodes 16 . A host of metal-based TCFs have been applied in solar cells , biological devices and flexible touchscreen panels and displays 9 , 12 . It has been proved as an alternative to ITO 17 , 18 Hybrid TCFs of Carbon-based materials, metals and conductive polymers can effectively utilize the advantage of a single material and complement the shortcomings of a single material 19 , 20 .…”

Invariant percolation properties in random isotropic systems of conductive discorectangles on a plane: From disks to sticks

“…The 2D systems of randomly-placed, metallic nanowires and nanorods are being extensively studied. The interest in these systems is inspired by their combination of high electrical conductivity with excellent optical transparency that is in demand in numerous technological applications [1,2] such as touch screens [3], transparent heaters [4], solar cells [5], and flexible electronics [6].…”