Blue emitting materials based on diphenylamine-substituted diphenylvinylarenes for OLEDs

ABSTRACT

To develop the efficient blue emitters for Organic light-emitting diodes (OLEDs), this paper reports the synthesis and electroluminescent properties of diphenylvinylarenes end-capped with diphenylamine groups. Two OLEDs were fabricated in the following sequence: indium-tin-oxide (ITO) / N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diam-ine (NPB) (50 nm) / Blue emitters (30 nm) / bathophenanthroline (Bphen) (30 nm) / lithium quinolate (Liq) (2 nm) /Al (100 nm). Two devices exhi-bited blue electroluminescence. In particular, a device using 9,9-diethyl-N,N-diphenyl-7-(2,2-diphenylvinyl)-9H-fluoren-2-amine exhibited blue emission with a luminance efficiency, a power efficiency, an external quantum efficiency and Commission Internationale d’Énclairage (CIE) coordinates of 5.48 cd/A, 2.45 lm/W, 2.85% at 20 mA/cm² and (x = 0.17, y = 0.25) at 8.0 V, respectively.

KEYWORDS:

• Blue OLED
• diphenylamine
• diphenylvinylarene
• fluorescence

Funding

This research was supported by the Samsung Display and Basic Science Research Program through the NRF funded by the Ministry of Education, Science and Technology, South Korea (NRF-2013R1A1A2A10008105).