High-Efficiency Deep-Blue Light-Emitting Diodes Based on Phenylquinoline/Carbazole-Based Compounds

Abstract

Highly efficient deep-blue fluorescent materials based on phenylquinoline-carbazole derivatives (PhQ-CVz, MeO-PhQ-CVz, and CN-PhQ-CVz) are synthesized for organic light-emitting diodes (OLEDs). The materials form high-quality amorphous thin films by thermal evaporation and the energy levels can be easily adjusted by the introduction of different electron-donating and electron-withdrawing groups on carbazoylphenylquinoline. Non-doped deep-blue OLEDs that use PhQ-CVz as the emitter show bright emission (Commission Internationale de L'Éclairage (CIE) coordinates, x = 0.156, y = 0.093) with an external quantum efficiency of 2.45%. Furthermore, the material works as an excellent host material for 4,4-bis(9-ethyl-3-carbazovinylene)-1,1-biphenyl dopant to get high-performance OLEDs with excellent deep-blue CIE coordinates (x = 0.155, y = 0.157), high power efficiency (5.98 lm W-1), and high external quantum efficiency (5.22%). ; This research was supported by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MEST) (No. M10600000157-06J0000-15710) and the University IT Research Center (ITRC) Project of the Ministry of Knowledge Economy.