Achieving Pure Deep-Blue Electroluminescence with CIE y≤0.06 via a Rational Design Approach for Highly Efficient Non-Doped Solution-Processed Organic Light-Emitting Diodes.
Deep-blue fluorescent emitters with Commission Internationale de l'Eclairage (CIE) y≤0.06 are urgently needed for high-density storage, full-color displays and solid-state lighting. However, developing such emitters with high color purity and efficiency in solution-processable non-doped organic light-emitting diodes (OLEDs) remains an important challenge. Here, we present the synthesis of two new deep-blue fluorescent emitters (AFpTPI and AFmTPI) based on 10-(9,9-diethyl-9H-fluoren-2-yl)-9,9-dimethyl-9,10-dihydroacridine as a core and 1,3- and/or 1,4-phenylene-linked triphenylimidazole (TPI) analogues for non-doped solution-processable OLEDs. Their thermal, photophysical, electrochemical, and device characteristics are explored, and also strongly supported by density functional theory (DFT) study. AFpTPI and AFmTPI exhibit excellent thermal stability (≈450 °C) with high glass transition temperatures (Tg; 141-152 °C) and deep-blue emission with high quantum yields. Specifically, the solution-processed non-doped device with AFpTPI as an emitter exhibits a maximum external quantum efficiency (EQE) of 4.56 % with CIE coordinates of (0.15, 0.06), which exactly matches the European Broadcasting Union (EBU) blue standard. In addition, AFmTPI also displays good efficiency and better color purity (EQE: 3.37 %; CIE (0.15, 0.05)). To the best of our knowledge, the present work is the first report on non-doped solution-processable OLEDs with efficiency close to 5 % and CIE y≤0.06.
Department of Chemistry Education, Graduate Department of Chemical Materials, Institute for Plastic Information and Energy Materials, Pusan National University, Busan, 609-735, Republic of Korea.
Saripally Sudhaker
SS
Reddy
Department of Chemistry Education, Graduate Department of Chemical Materials, Institute for Plastic Information and Energy Materials, Pusan National University, Busan, 609-735, Republic of Korea.
Vijaya Gopalan
VG
Sree
Department of Chemistry Education, Graduate Department of Chemical Materials, Institute for Plastic Information and Energy Materials, Pusan National University, Busan, 609-735, Republic of Korea.
Woosum
W
Cho
Department of Chemistry Education, Graduate Department of Chemical Materials, Institute for Plastic Information and Energy Materials, Pusan National University, Busan, 609-735, Republic of Korea.
Sung-Ho
http://orcid.org/0000-0001-6631-983X
SH
Jin
9,9-dimethyl-9,10-dihydroacridine/triphenylimidazole; deep-blue electroluminescence; fluorescence; non-doped OLEDs; solution-process