Highly Stable Silver Nanowire Plasmonic Electrodes for Flexible Polymer Light-Emitting Devices

Silver nanowire (AgNW) transparent electrodes are considered as a promising candidate for applications in flexible optoelectronic devices. However, it remains a great challenge to obtain flexible AgNW electrodes with excellent optoelectrical properties and mechanical flexibility. Here, highly stable Ag nanoparticle (AgNP)-enhanced plasmonic AgNW electrodes are demonstrated via the controllable in situ growth of AgNPs at the AgNW junctions and introduction of an l-histidine (l-His) wrapping layer. The flexible transparent electrodes of AgNW-AgNP/l-His possess a low sheet resistance (R_sh) of ∼17.5 Ω sq^-1, a high transmittance of ∼92.5% (550 nm), and a robust mechanical stability (100,000 bending cycles). Benefiting from plasmon-coupling effects, flexible polymer light-emitting devices (FPLEDs) with AgNW-AgNP/l-His electrodes present a current efficiency (CE) of ∼14.8 cd A^-1 and an external quantum efficiency (EQE) of ∼5.6%, constituting ∼80% and ∼75% increases compared to those of the reference devices with AgNW electrodes, respectively. Additionally, the laminated flexible transparent PLEDs (FT-PLEDs) are demonstrated by integrating polydimethylsiloxane/AgNW-AgNP anodes by a soft lamination process. The FT-PLEDs present a CE of ∼7.1 cd A^-1 (cathode side: ∼3.9 cd A^-1; anode side: ∼3.2 cd A^-1) and an EQE of ∼2.7% (cathode side: ∼1.5%; anode side: ∼1.2%). Furthermore, the FPLEDs and FT-PLEDs exhibit robust mechanical durability, maintaining ∼89% and ∼86% of their initial luminance after 1000 bending cycles at a bending radius of 2 mm, respectively. This work opens up a new avenue for the development of high performance and stable flexible optoelectronic devices.