A flexible plasma-treated silver-nanowire electrode for organic light-emitting devices

Abstract

Silver nanowires (AgNWs) are a promising candidate to replace indium tin oxide (ITO) as transparent electrode material. However, the loose contact at the junction of the AgNWs and residual surfactant polyvinylpyrrolidone (PVP) increase the sheet resistance of the AgNWs. In this paper, an argon (Ar) plasma treatment method is applied to pristine AgNWs to remove the PVP layer and enhance the contact between AgNWs. By adjusting the processing time, we obtained AgNWs with a sheet resistance of 7.2Ω/□ and a transmittance of 78% at 550 nm. To reduce the surface roughness of the AgNWs, a peel-off process was used to transfer the AgNWs to a flexible NOA63 substrate. Then, an OLED was fabricated with the plasma-treated AgNWs electrode as anode. The highest brightness (27000 cd/m2) and current efficiency (11.8 cd/A) was achieved with a 30 nm thick light emitting layer of tris-(8-hydroxyquinoline) aluminum doped with 1% 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5 H,11H-(1)-benzopyropyrano(6,7-8-I,j)quinolizin-11-one. Compared to thermal annealing, the plasma-treated AgNW film has a lower sheet resistance, a shorter processing time, and a better hole-injection. Our results indicate that plasma treatment is an effective and efficient method to enhance the conductivity of AgNW films, and the plasma-treated AgNW electrode is suitable to manufacture flexible organic optoelectronic devices.

High performing AgNW transparent conducting electrodes with a sheet resistance of 2.5 Ω Sq−1 based upon a roll-to-roll compatible post-processing technique

“…Post-processing has been used to improve the electrical properties of AgNWs including by annealing, 'hot rolling' and rinsing with chemicals that remove impurities such as polyvinylpyrrolidone (PVP). [16][17][18][19][20][21][22] Currently the best combined electrical/optical performance was reported by Preston et al, 23 who demonstrated a TCE with a transmittance of 91% and a low sheet resistance of 13 Ω sq −1 . By considering the trade-off between electrical and optical performance, a figure of merit (FoM) as defined using eqn (1) is often quoted 6 which can be calculated for the work of Preston et al as 300.…”

Uniform and bright light emission from a 3D organic light-emitting device fabricated on a bi-convex lens by a vortex-flow-assisted solution-coating method

“…Finally, it is important to comment on the Ag-NW anode on the bi-convex lens surface used in this study, which was fabricated by the transfer method 42 . To transfer Ag-NWs onto the lens surface, an Ag-NW suspension was also coated onto a concave substrate using our vortex-spin-coating method, after which the coated Ag-NW layer on the concave surface was transported to the lens surface.…”

Multiscale Soft–Hard Interface Design for Flexible Hybrid Electronics

“…[30] However, overprocessing of soft ligands may lead to dramatic structural changes of AgNWs leading to fragmentation, which, in turn, affects the mechanical flexibility and electrical conductivity. [72,73] The poor compatibility of AgNWs in the elastomeric matrix is another reason for the poor mechanical and electrical properties of the resulting FHEs. Consequently, a ligand exchange process is often required to facilitate the homogenous distribution of AgNWs in elastomeric media.…”