Luminance materials containing carbazole and triphenylamine exhibiting high hole-transporting properties

Two novel 2-substitutd-8-hydroxyquinoline derivatives were designed and synthesized. Their luminance properties and carrier transporting abilities were studied when integrated in four different organic light-emitting device structures. The four devices are structured as following-device A: indium tin oxide glass substrate (ITO)/2-TNATA/NPB/(2-[2-(9-ethyl-9H-carbazol-2-yl)-vinyl]-quinolato zinc (1) and 2-[2-(4-diphenylamino-phenyl)-vinyl]-quinolato zinc (2))/Alq(3)/LiF/aluminum (Al); device B: ITO/2-TNATA/NPB/1 or 2/LiF/Al: device C: ITO/2-TNATA/1 or 2/Alq(3)/LiF/Al; device D: ITO/2-TNATA/1 or 2/Alq(3)/LiF/Al. In the device A, the maximum brightness of compound 1 is 5857 cd m(-2) at 11 V with the luminance efficiency 1.84cd A(-1). For 2 it is 6047 cd m(-2) at 10V with an efficiency of 2.22 cd A(-1). In the device B, the maximum brightness of 1 is 745 cd m(-2) at 11 V and efficiency is 0.32 cd A(-1). These values are 1748 cd m(-2) at 10V and 0.42 cd A(-1) for 2, respectively. In the device C, the maximum brightness of 1 and 2 are 8729 and 5838cd m(-2) at 10V, respectively, with an efficiency of 1.99 and 1.71 cd A(-1). In the device D, the maximum brightness and efficiency of 1 are 8512 cd m(-2) at 13 V and 3.10 cd A(-1), and they are 9818 cd m(-2) at 13V and 0.42 cd A(-1), for 2. Our results also show that both 1 and 2 are good bipolar and bifunctional molecules with high hole-transporting and luminance properties. (C) 2009 Elsevier B.V. All rights reserved.