Synthesis and characterization of novel red-light-emitting materials with push-pull structure based on benzo[1,2,5]thiadiazole containing arylamine as an electron donor and cyanide as an electron acceptor

Abstract

New efficient red emitter having short π-conjugation length and asymmetric bulky structure, 2-(7-diphenylamino-benzo[1,2,5]thiadiazole-4- ylmethylene)-malononitrile, was synthesized and characterized. Using this material as a dopant, we fabricated electroluminescence device with a structure of ITO/DNTPD/NPD/BTZA (5 wt% in Alq3)/Alq3/LiF/Al. The device exhibited a high brightness of 761 cd/m2 at a driving voltage of 4.8 V, and current efficiency is 0.75 cd/A. The Commission International de I'Eclairage (CIE) coordinates of the EL device were found to be (0.62, 0.37) at 10 mA/cm2.