Derivative of oxygafluorene and di-tert-butyl carbazole as the host with very high hole mobility for high-efficiency blue phosphorescent organic light-emitting diodes

• Published in: Dyes and pigments 2016-07, Vol.130, p.298-305
• Main Authors: Gudeika, Dalius, Volyniuk, Dmytro, Grazulevicius, Juozas V., Skuodis, Eigirdas, Yu, Sian-Yin, Liou, Wei-Tong, Chen, Li-Yin, Shiu, Yi-Jiun
• Format: Article
• Language: English
• Subjects: Blue electrophosphorescence; Carbazole; Carbazoles; Derivatives; Devices; Electric fields; Hole mobility; Hole transport; Host; Organic light-emitting diodes; Oxygafluorene; Phosphorescence; Weight loss
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2016.03.039

Derivative of oxygafluorene and di-tert-butyl carbazole was synthesized as the host material for high-efficiency blue phosphorescent organic light-emitting diodes. It exhibited moderate thermal stability with 5% weight loss temperature of 337 °C and glass-forming ability with the glass-transition temperature of 65 °C. The solid-state ionization potential of di-tert-butyl carbazolyl-substituted oxygafluorene was found to be 5.54 eV as established by electron photoemission spectrometry. It showed low-dispersity hole transport with time-of-flight hole mobilities of 10−2 cm2 V−1 s−1 observed at high electric fields. Blue devices based on the synthesized compound showed high external quantum efficiency up to 16.5% and low efficiency roll-off. •Derivative of oxygafluorene and di-tert-butyl carbazole was synthesized.•The solid sample showed triplet energy of 2.81 eV.•The hole mobility reached 10−2 cm2V−1s−1 at high electric fields.•Blue devices showed external quantum efficiency of 16.5%.