Roll‐to‐Roll Production of Graphene Hybrid Electrodes for High‐Efficiency, Flexible Organic Photoelectronics

Abstract

transparent conductive electrode and substrate material is the combination of indium tin oxide (ITO) and glass with a share of over 95% throughout the scientifi c community. [ 2 ] Future commercial electronic devices require versatile features, such as fl exibility, being lightweight and low cost, wearability, and a superior mechanical stability. [ 3,4 ] In addition, the fabrication of such devices is based on solution processing methods known as "printable electronics," which ultimately integrate multidimensional roll-to-roll (R2R) processing. [ 4 ] These techniques require high-performance fl exible transparent electrodes (FTEs) fabricated on plastic substrates; currently, they depend on ITO coated on plastic substrates. However, it has several intrinsic weaknesses such as limited indium sources, unsuitability for commercial fl exible electronic devices, inferior physical properties for high temperature treatment (over 150 °C), high mechanical brittleness, expensive cost involved in preparation processes (pulsed laser deposition, sputtering, and evaporation), and high portion (more than 50%) in material consumption of organic optoelectronic fabrication. [ 5 ] Therefore, it is urgently desirable to fi nd new materials to replace ITO for FTEs. Candidate materials for FTEs include new transparent metal oxide (aluminium-doped zinc oxide (AZO), [ 6 ] fl uorine tin oxide (FTO), [ 7 ] etc.), conducting polymers (CPs), [ 8 ] functional carbon materials (Graphenes and carbon nanotubes (CNTs)), [ 9 ] metal nanomaterials, [ 10 ] etc. However, each of these materials exhibits problems, for instance, lack of uniformity and reproducibility, diffi culty in mass production, expensive cost, etc., [ 11,12 ] which must be resolved before they can be implemented in commercial applications.Conducting polymer (CP), especially poly(3,4-ethylenedioxyt hiophene):poly(styrene sulfonate) (PEDOT:PSS), has been considered a promising candidate for FTEs due to its mechanical fl exibility, high transparency in the visible light spectrum, and compatibility with R2R technology, which allows for the escape of high-vacuum and high-temperature processes. [ 13 ] Note that, it also suffers from some fatal problems such as hygroscopy, acidity, sensitivity to oxygen exposure, and the relatively low values of electrical conductivity (0-10 2 S cm −1 ), which have been a bottleneck for the realization of high-performance FTEs. [ 14,15 ] Despite nearly two decades of research, the absence of ideal, fl exible, and transparent electrodes has been the biggest bottleneck for realizing fl exible and printable electronics via roll-to-roll (

Roll‐to‐Roll Fabrication of Flexible Orientated Graphene Transparent Electrodes by Shear Force and One‐Step Reducing Post‐Treatment

“…The X‐ray diffraction (XRD) patterns of PEDOT:PSS and PEDOT:PSS/HI films are revealed in Figure b. The peaks of 2θ at 3.8° and 23–26° are main characteristic peaks for carbon materials (PEDOT and GO) . It is an evident change in d (100) peak of the FTEs with and without HI treatment.…”

“…It requires that FTEs have versatile features, such as superior optoelectronic properties, lightweight portability, low cost, and mechanical flexibility . In addition, preparation of FTEs is based on printable methods, which can be ultimately integrated in roll‐to‐roll processing . The indium tin oxide is the prototypical material for FTEs, but film fragility, high cost (materials and fabricating process), and dissatisfactory optoelectronic property are inevitable barriers for certain commercial applications …”

Roller‐Assisted Adhesion Imprinting for High‐Throughput Manufacturing of Wearable and Stretchable Organic Light‐Emitting Devices

“…Roller‐associated technology is one of the technologies satisfying the demand of high‐throughput production, such as roller imprinting of large‐area micro/nanostructures and roll‐to‐roll production of electronic devices, and has been widely explored from laboratory to industrial production. Here, inspired by this technique, we developed an innovative roller‐assisted adhesion imprinting (RAI) toward high‐throughput and large‐area manufacturing of SOLEDs with ordered wrinkles.…”

“…Among these various stretching strategies, ordered wrinkles-based SOLEDs are able to satisfy these requirements by exhibiting 100% strechability, high efficiency of 70 cd A −1 , and cyclic stretching stability of withstanding 20 000 stretch-release cycles, respectively. [1,19] However, highthroughput, large-area, and cost-efficient manufacturing of the ordered wrinkles-based SOLEDs is still a challenge.Roller-associated technology is one of the technologies satisfying the demand of high-throughput production, such as roller imprinting of large-area micro/nanostructures [21][22][23][24] and roll-to-roll production of electronic devices, [25][26][27][28][29] and has been widely explored from laboratory to industrial production. Here, inspired by this technique, we developed an innovative rollerassisted adhesion imprinting (RAI) toward high-throughput and large-area manufacturing of SOLEDs with ordered wrinkles.…”

Conductive inks and films via intense pulsed light.

“…To find the figure of merit at 90% transmissivity (ϕTC), the equations can be adjusted to Equation With this equation, again the higher numbers indicate higher performance. In that same study FOM values were reported for rGO films reported in the range of .189 to 0.232, 21 70.0 for Ag NWs, and 134.4 to 189.9 for their hybrid Ag NW/rGO films (whereas a typical FOM value for ITO would be 297). 17 FOMs of the aforementioned TCFs in Table 1 have been calculated and are displayed in Figure 10.…”