Fabrication of Color-Tunable Blue-Violet Organic Light Emitting Diodes for White Light Source. (1st January 2016)

• Record Type: Journal Article
• Authors: Lu, Hsin-Wei; Weng, Huei-Ling; Kao, Po-Ching; Chu, Sheng-Yuan; Juang, Yung-Der
• Is Part Of: ECS journal of solid state science and technology. Volume 5:Number 6(2016)
• Page Start: R104
• Page End: R109
• Publication Date: 2016-01-01
• Subjects: down color conversion layer -- electroplex -- WOLEDs; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0151606jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : 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/m 2 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/m 2, with measured CIE chromaticity coordinates of (0.333, 0.351) in the WOLEDs.