Synthesis and Electroluminescent Properties of t-Butylated 2-(2-(4-(Diarylamino)styryl)-4H-chromen-4-ylidene)malononitrile Derivatives for OLED

Abstract

We designed and synthesized new red fluorescent materials based on t-butylated 2-(2-(4-(diarylamino)styryl)-4H-chromen-4-ylidene)malononitrile derivatives (3a-3d). A device using 2-(6,8-di-tert-butyl-2-(4-((4-tert-butylphenyl)(2,7-di-tert-butyl-9,9-diethyl-9H-fluoren-4-yl)amino)styryl)-4H-chromen-4-ylidene)malononitrile (3a) as a dopant showed efficient red electroluminescent properties with a maximum luminance of 3357 cd/m² at 15.0 V, and maximum luminous and power efficiencies of 1.12 cd/A and 0.60 lm/W, respectively. The CIE coordinates of this device using this material was (0.64, 0.35) at 7.0 V, and this device also showed stable color chromaticity at various voltages.

Keywords:

• OLED
• Red fluorescence
• chromene groups
• tert-Butyl groups.