Novel Fluoranthene-Based Molecules as Electron Transport and Electroluminescent Materials for Blue Organic Light-Emitting Diodes

Shiv Kumar1,  Bo Li2,  Qisheng Zhang2,  Chihaya Adachi2,  Satish Patil1
1Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 INDIA, 2Center for Organic Photonics and Electronics Research, Kyushu University, Fukuoka 819-0395, JAPAN


Abstract

Here we explore the novel fluoranthene derivatives, bis(4-(7,9,10-triphenylfluoranthen-8-yl)-phenyl)sulfone (TPFDPSO2) and 2,8-bis(7,9,10-triphenylfluoranthen-8-yl)dibenzo[b,d]-thiophene 5,5-dioxide (TPFDBTO2) as electron transport and electroluminescent materials for organic light-emitting diodes (OLEDs). These derivatives were synthesized via Diels-Alder cycloaddition reaction and characterized by elemental analysis, IR & NMR spectroscopy and mass spectrometry. Their optical properties show deep blue fluorescence emission with high photoluminescence quantum yield (PLQY) in both solution and solid state. The thermal properties studied by DSC and TGA show high glass transition temperature and decomposition temperature. The energy levels of these compounds determined by cyclic voltammetry. The charge transport properties of these derivatives were investigated by means of hole-only and electron-only devices. A bilayer organic light-emitting diode (OLEDs) fabricated using these fluoranthene derivatives as electron transport and emitting layer displayed bright sky blue color emission with moderate electroluminescence performance, EQE of 0.5-0.6 %.