Red Fluorescent 4-(Dicyanomethylene)-2- (1-pentylbicyclo[2,2,2]oct-4-yl)-6-(1,1,2,2,7,7-hexamethyljulolidyl-9-enyl)-4H-pyran (DCHMJPB) for Organic Light-Emitting Diodes (OLEDs)

Abstract

An efficient red fluorescent compound, 4-(Dicyanomethylene)-2-(1-pentylbicyclo- [2,2,2]oct-4-yl)-6-(1,1,2,2,7,7-hexamethyljulolidyl-9-enyl)-4H-pyran (DCHMJPB) containing two additional methyl groups on julolidine moiety and 1-pentylbicyclo- [2,2,2]octyl group on pyran moiety, was synthesized and characterized. In this red emitter, the bulky groups such as two additional methyl groups and 1-pentylbicyclo- [2,2,2]octyl group were introduced to increase the steric hindrance between the red emitters and prevent concentration quenching. In particular, in an efficient red device containing emitter DCHMJPB as a dopant, a luminous and power efficiency of 3.76 cd/A and 1.97 lm/W was achieved, respectively, at 20 mA/cm2 with the CIE coordinates of (x = 0.56, y = 0.42) at 7.0V.