Ultrathin Graphene Intercalation in PEDOT:PSS/Colorless Polyimide-Based Transparent Electrodes for Enhancement of Optoelectronic Performance and Operational Stability of Organic Devices

Abstract

A novel flexible transparent electrode (TE) having a trilayer-stacked geometry and high optoelectronic performance and operational stability was fabricated by the spin coating method. The trilayer was composed of an ultrathin graphene (Gr) film sandwiched between a transparent and colorless polyimide (TCPI) layer and a m e t h a n e s u l f o n i c a c i d ( M S A ) -t r e a t e d p o l y ( 3 , 4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer containing dimethylsulfoxide and Zonyl fluorosurfactant (designated as MSA-PDZ film). The introduction of solution-processable TCPI enabled the direct formation of high-quality graphene on organic surfaces with a clean interface. Stable doping of graphene with the MSA-PDZ film enabled tuning of the inherent work function and optoelectronic properties of the PEDOT:PSS films, leading to a high figure of merit of ∼70 in the as-fabricated TEs. Particularly, from multivariate and repetitive harsh environmental tests (T = −50 to 90 °C, over 90 RH%), the TCPI/Gr heterostructure exhibited excellent tolerance to mechanical and thermal stresses and gas barrier properties that protected the MSA-PDZ film from exposure to moisture. Owing to the synergetic effect from the TCPI/Gr/MSA-PDZ anode structure, the TCPI/Gr/MSA-PDZ-based polymer light-emitting diodes showed highly improved current and power efficiencies with maxima as high as 20.84 cd/A and 22.92 lm/W, respectively (comparable to those of indium tin oxide based PLEDs), in addition to much enhanced mechanical flexibility.

Polymer-Laminated Ti3C2TX MXene Electrodes for Transparent and Flexible Field-Driven Electronics

“…, field effect transistors), is of great interest due to their potential in emerging human-interactive electronics , that require efficient and convenient human–machine communication. One of the most challenging issues regarding the realization of such device elements is the development of a solution-processable transparent electrode with a sufficiently high conductivity comparable to that of commercially available rigid indium tin oxide (ITO). − Although various solution-processable, low-dimensional nanoscale conductors have been developed, such as carbon nanotubes, − reduced graphene oxides, , and Ag nanowires, , the results are unsatisfactory owing to various material and technological limitations, such as low conductivity (high surface resistance) and poor film quality, arising from the intrinsic structural defects and numerous physical junctions of the nanoconductors required for percolated networks. − Conducting polymers ( e.g. , poly­(3,4-ethylenedioxythiophene)­polystyrenesulfonate (PEDOT:PSS)) with optical transparency as well as mechanical flexibility have also been limited by the relatively low conductivity for the application of field-driven electronic devices. , …”

Biomedical and Tissue Engineering Strategies to Control Foreign Body Reaction to Invasive Neural Electrodes

“…Accordingly, the use of dexamethasone could be combined with tissue engineering strategies, such as substrate functionalization with biodegradable hydrogels and porous CPs, for its controlled local release in order to specifically target its activity around the implant, while reducing potential side effects caused by its systemic toxicity at too high doses. In relation to this approach, one of the first in vitro attempts to control the release of dexamethasone from a conducting polymer coating of PPy on Au electrode 2018) Lago et al, 2007;Garde et al, 2009;Mercanzini et al, 2010;Chang et al, 2013;Hassler et al, 2016;Oddo et al, 2016;Boehler et al, 2017;Delgado-Martínez et al, 2017;Wurth et al, 2017;de la Oliva et al, 2018b,c;Ji et al, 2018;Kang et al, 2019;Lee et al, 2019;Rombaut et al, 2019 Parylene C Reviewed in Fekete andPongrácz (2017) Ziegler et al, 2006;Sohal et al, 2014;Xie et al, 2014;Lecomte et al, 2017;Mueller et al, 2017;de la Oliva et al, 2018a,b;Vitale et al, 2018;Kang et al, 2019PDMS Blau et al, 2011Gao et al, 2013;Guo et al, 2014;Minev et al, 2015;Chatzimichail et al, 2018;Kumar et Poly(carboxybetaine) and pCBMA Jiang and Cao, 2010;Carr et al, 2011;Zhang et al, 2013;Trel'Ová et al, 2019 Phosphorylcholine self-assembled monolayers Chen et al, 2005 Poly(sulfobetaine) and pSBMA Reviewed in Sin et al (2014a) Jiang and...…”

“…Very recently, a flexible and transparent polyimide-based electrode was fabricated with a trilayer-stacked geometry that exploits the properties of a high-quality ultrathin film of graphene. This solution showed enhanced power and current efficiencies, with properties comparable to indium tin oxide-based diodes, increased flexibility and long-term stability in different devices ( Lee et al, 2019 ). Finally, another strategy to increase the long-term reliability, while maintaining high flexibility, of a polyimide-based neural interface in free-moving rats, was the one adopted by a research group from China, through a MEMS fabrication approach ( Ji et al, 2018 ).…”

Surface adhesion engineering for robust organic semiconductor devices

“…39 Therefore, devices need to be mechanically and electrically robust if they are to work efficiently for decades. Among many factors that affect the stability of organic semiconductor devices, 40–43 an important but often overlooked problem is the weak interfacial adhesion between organic semiconductors and supporting substrates. Considering that interface friction, torsion or collision often occurs under long-term work in complex environments, the interfacial adhesion is very critical for the stability of organic semiconductor devices.…”