Nanodot-Enhanced High-Efficiency Pure-White Organic Light-Emitting Diodes with Mixed-Host Structures

A relatively high‐efficiency, fluorescent pure‐white organic light‐emitting diode was fabricated using a polysilicic acid (PSA) nanodot‐embedded polymeric hole‐transporting layer (HTL). The diode employed a mixed host in the single emissive layer, which comprised 0.5 wt % yellow 5,6,11,12‐tetra‐phenylnaphthacene doped in the mixed host of 50 % 2‐(N,N‐diphenyl‐amino)‐6‐[4‐(N,N‐diphenylamino)styryl]naphthalene and 50 % N,N′‐bis‐(1‐naphthyl)‐N,N′‐diphenyl‐1,10‐biphenyl‐4‐4′‐diamine. By incorporating 7 wt % 3 nm PSA nanodot into the HTL of poly(3,4‐ethylene‐dioxythiophene)‐poly‐(styrenesulfonate), the efficiency at 100 cd m–2 was increased from 13.5 lm W–1 (14.7 cd A–1; EQE: 7.2 %) to 17.1 lm W–1 (17.6 cd A–1; EQE: 8.3 %). The marked efficiency improvement may be attributed to the introduction of the PSA nanodot, leading to a better carrier‐injection‐balance. High‐efficiency pure‐white fluorescent organic light‐emitting diodes (OLEDs) are fabricated using small polysilicic acid (PSA) nanodot embedded polymeric hole‐transporting layer. By incorporating 3 nm PSA nanodots into poly(3,4‐ethylenedioxythiophene), the white OLEDs show an efficiency of 17.1 lm W–1 at 100 cd m–2.