In this study, blue-violet organic light emitting diodes (BV-OLEDs, ITO/MoO3 (Y nm)/4,4' -bis(9-carba-zolyl)-2,2' -biphenyl (CBP) (X nm)/1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBi) (100-X nm)/LiF (1 nm)/Al (100 nm)) were fabricated with the simple bilayer structure of CBP and TPBi, leading to a maximum luminance of 1280 cd/m2 when the thicknesses of the MoO3 , CBP, and TPBi were 4, 35 and 65 nm, respectively. The blue-shift of the electroluminescence was observed from various viewing angles, and is attributed to the micro-cavity effects. Further, it was observed that the Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of the devices changed from (0.19, 0.102; at 4 V) to (0.333, 0.366; at 11 V) due to the electroplex effect between the CBP and TPBi at high voltage. Subsequently, simple white OLEDs (WOLEDs) were fabricated by combining the proposed BV-OLEDs with the down color conversion layer (CCL). The down CCL of the 5 wt% 5,6,11,12-tetraphenylnaphthacene (Rubrene)-doped 4,4' -bis(2,2-diphenylvinyl)-1,1' -biphenyl (DPVBi) had the highest maximum luminance of 1240 cd/m2 , with measured CIE chromaticity coordinates of (0.333, 0.351) in the WOLEDs.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials