Realization of efficient light out-coupling in organic light-emitting diodes with surface carbon-coated magnetic
Qingchen Dong1, Feifei Tai1, Hong Lian1
1MOE Key Laboratory of Interface Science and Engineering in Advanced Materials and Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan 030024, P.R. China. dongqingchen@tyut.edu.cn.
Abstract:
A significant enhancement in light extraction in organic light-emitting diodes (OLEDs) is realized by using composite hole transport layers (HTLs) with surface carbon-coated magnetic alloy nanoparticles (NPs). Compared to the control device with a standard architecture, the current efficiencies of fluorescent green OLEDs can be enhanced by 47.1% and 48.5% by mixing the surface carbon-coated magnetic FePt (0.5 wt‰) and CoPt (0.5 wt‰) alloy NPs into poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), yielding the maximum values of 5.40 cd A-1 and 5.45 cd A-1, respectively. The presence of an alloy NP-incorporated PEDOT:PSS HTL also acts as an optical out-coupling layer contributing to the efficiency enhancement, accomplished through the collective effects of light-scattering, localized surface plasmon resonance and increased electron trap density induced by magnetic alloy NPs.
