Highly efficient soluble materials for blue phosphorescent organic light-emitting diode

作者：Lee Nam Jin; Lee Dae Hee; Kim Dong Won; Lee Ji Hoon; Cho Sang Hee; Jeon Woo Sik; Kwon Jang Hyuk; Suh Min Chul^*

来源：Dyes and Pigments, 2012, 95(2): 221-228.

DOI：10.1016/j.dyepig.2012.04.011

• Soluble host materials
• Blue phosphorescent OLED
• Carbazole
• Sterically bulky side groups
• High triplet energy

A series of new carbazole derivatives with good solubility and electronic properties for use as host materials for blue phosphorescent organic light-emitting diodes is reported. A twisted biphenyl moiety at the center of the host materials was applied to enhance the solubility as well as triplet energies. Hence all the molecules showed good solubility as well as a fairly large triplet energy up to 3.01 eV. Blue phosphorescent devices employing bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium (III) as the guest and the three new twisted carbazole derivatives as co-hosts with an electron type host material exhibited high efficiencies, up to 20.7 cd/A as a maximum current efficiency and 12.5% of external quantum efficiency. This performance was much improved by similar to 27.6%, compared to that measured for the 1,3-di(9H-carbazol-9-yl)benzene: 2,6-bis(3-(9H-carbozol-9-yl)phenyl)pyridine reference system.

• 出版日期2012-11