Red Fluorescent Materials Based on Julolidine/Chromene with the Bulky Tert-Butyl and Trimethylsilyl Substituents for Organic Light-Emitting Diodes

초록

In this work, we designed and synthesized two red emitters 2-(6,8-di-tert-butyl-2-(2-(1,1-dimethyl-7-(trimethylsilyl)-7-((trimethylsilyl) methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-9-yl) vinyl)-4H-chromen-4-ylidene) malononitrile (Red 1) and 2-(6,8-di-tert-butyl-2-(2-(1,1,7-trimethyl-7-t-butyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij] quinolin-9-yl) vinyl)-4H-chromen-4-ylidene) malononitrile (Red 2). To explore the electro-luminescence properties of these materials, multilayered OLEDs using these materials as dopants in a Alq(3) host were fabricated. Particularly, by using Red 1 as a dopant in emitting layer, device 1 showed the luminous and power efficiencies of 0.81 cd/A and 0.43 lm/W at 20 mA/cm(2), respectively. The CIE coordinates of this device was (0.65, 0.34) at 7.0 V, which is close to the NTSC standard CIE coordinates of (0.67, 0.32) for red emission.

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