Synthesis and electro-optical properties of spiro based host material for thermal stable blue phosphorescent OLED

ABSTRACT

New host material, namely 2,2′-bis(3,5-di(9H-carbazol-9-yl)phenyl)-9,9′-spirobi[fluorene] (spiro-mCP), was designed and synthesized by the palladium-catalyzed Suzuki coupling reaction between 9,9′-(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3-phenylene)bis (9H-carbazole) and 2,2′-diiodo-9,9′-spirobi[fluorene]. Thermal, photophysical and electrochemical properties of spiro-mCP were investigated. Using spiro core leads to enhance thermal stability. Phosphorescent organic light-emitting diode constructed using a 7 wt% FIr6 doped spiro-mCP emitting layer produces bright blue emissions with a high luminescence efficiency of 5.8 cd/A.

KEYWORDS:

• Light-emitting diode
• spiro structure
• thermostability
• host material