Efficient solution processed hybrid white organic light-emitting diodes based on a blue thermally activated delayed fluorescence emitter

• Published in: Thin solid films Vol. 695; p. 137753
• Main Authors: Joo, Chul Woong, Huseynova, Gunel, Kim, Ji Hye, Yoo, Jae-Min, Kim, Yong Hyun, Cho, Nam Sung, Lee, Jae-Hyun, Kim, Yun-Hi, Lee, Jonghee
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2020
• Subjects: Blue emitter; Solution-processed devices; Thermally activated delayed fluorescence; White organic light-emitting diodes, Hybrid organic light emitting devices; Thermally activated delayed fluorescence; Blue emitter; Solution-processed devices; White organic light-emitting diodes, Hybrid organic light emitting devices
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2019.137753

•Solution-processed white organic light-emitting diodes were developed.•Thermally activated delayed fluorescence blue emitter was utilized.•High efficiency of 11.02 % and 22.46 cd/A were obtained.•CIE coordinates of (0.43, 0.40) were achieved with single emissive layer. A solution-processed blue thermally activated delayed fluorescence (TADF) aromatic molecule has been introduced to realize high-efficiency hybrid white organic light-emitting diodes (WOLEDs) with very simple structure which contains only three organic layers of hole injection layer, emissive layer (EML), and electron transporting layer. 1,3-Bis(N-carbazolyl)benzene doped with the blue TADF molecule 10-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-methylphenyl)-10H-spiro[acridine-9,9′-fluorene] was mixed with a red phosphorescent emitter, bis(2-methyldibenzo[f,h]quinoxaline) (acetylacetonate) iridium(III) to form a blue-red fluorescent-phosphorescent hybrid EML. The resultant hybrid EML was applied to construct a solution-processed WOLEDs. Hence, a maximum external quantum efficiency of 11.02% and current efficiency of 22.46 cd/A with the Commission Internationale de L'Eclairage coordinates of (0.43, 0.40) were achieved by co-doping of blue and red emitters in a single layer.