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[International Journal] [Back Cover] Enhanced Light Extraction from Mechanically Flexible, Nanostructured Organic Light-Emitting Diodes with Plasmonic Nanomesh Electrodes
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Sung-min Lee, Yunil Cho, Dong-Young Kim, Joon-Sik Chae and Kyung Cheol Choi

Advanced Optical Materials, September , 2015


vol 3, no 9, pp 1240-1247

Characteristics of light extraction from nanostructured organic light-emitting
diodes (OLEDs) incorporating plasmonic metal nanomesh anodes are investi-
gated for achieving high-performance, fl exible OLEDs. Given that fl exibility of
devices is limited by rigid and fragile constituents such as indium tin oxide elec-
trodes, alternative transparent, and fl exible electrodes including nanomesh-type
metal fi lms have been widely studied, where high transparency, low resistance,
and good fl exiblity were regarded as essential requirements of high-perfor-
mance fl exible applications due to the expectation that they are closely related
to the device performance. However, here it is reported that a metal nanomesh
optimized for high transmittance cannot promise high device effi ciency when it
is used as an anode of OLEDs. Systematic experiments together with analytic
simulations elucidate that the surface plasmon loss is singnifi cantly reduced by
metallic cathode nanostructures that were inherently formed from a periodic
nanomesh anode, which results in huge enhancement of the light extraction,
though the optimal period of the nanomesh anode for high light extraction is
inconsistent with that for high transmittance. Further performance characteri-
zation of nanostructured OLEDs with metal nanomesh anodes provides insight
into strategies to realize highly effi cient fl exible OLEDs.