Synergetic electrode architecture for efficient graphene-based flexible organic light-emitting diodes

Abstract

Graphene-based organic light-emitting diodes (OLEDs) have recently emerged as a key element essential in next-generation displays and lighting, mainly due to their promise for highly flexible light sources. However, their efficiency has been, at best, similar to that of conventional, indium tin oxide-based counterparts. We here propose an ideal electrode structure based on a synergetic interplay of high-index TiO2 layers and low-index hole-injection layers sandwiching graphene electrodes, which results in an ideal situation where enhancement by cavity resonance is maximized yet loss to surface plasmon polariton is mitigated. The proposed approach leads to OLEDs exhibiting ultrahigh external quantum efficiency of 40.8 and 62.1% (64.7 and 103% with a half-ball lens) for single- and multi-junction devices, respectively. The OLEDs made on plastics with those electrodes are repeatedly bendable at a radius of 2.3 mm, partly due to the TiO2 layers withstanding flexural strain up to 4% via crack-deflection toughening.

Selective multi-nanosoldering for fabrication of advanced solution-processed micro/nanoscale metal grid structures

“…The highly conductive PEDOT:PSS (PH 1000 with 5 wt% of DMSO, 50 nm, 242 Ω sq −1 ) was used as a buffer transparent electrode on top of the flexible metal grid TCs. The low conductive PEDOT:PSS (PVP AI4083, 50 nm) and MoO 3 were used as a hole injection layer 31 . On top of the MoO 3 , organic layers and metal electrode were sequentially deposited using thermal evaporator, and the detailed configuration is described in the experimental section.…”

Flexible, polymer gated, AC-driven organic electroluminescence devices

“…The improved flexibility of PFN-Br polymeric layer enormously advances the inorganic gate layer 13 and allows us to fabricate mechanically flexible gated AC-OEL devices with relatively high performance. The PFN-Br gate was laid down on the cleaned ITO/PET substrate by spin-coating.…”

33‐2: Flexible OLED Panels with Pixilated Graphene Anode

“…Thus, graphene has been suggested as a promising candidate as a flexible transparent electrode. Many graphene transparent electrode containing devices have been reported in the literature [6][7][8][9]. However, the process difficulties have impeded the appearance of commercial products [10].…”