Silicon-based material with spiro-annulated fluorene/triphenylamine as host and exciton-blocking layer for blue electrophosphorescent devices

摘要

A novel silicon-based compound, 10-phenyl-2′-(triphenylsilyl)-10H- spiro[acridine-9,9′-fluorene] (SSTF), with spiro structure has been designed, synthesized, and characterized. Its thermal, electronic absorption, and photoluminescence properties were studied. Its energy levels make it suitable as a host material or exciton-blocking material in blue phosphorescent organic light-emitting diodes (PhOLEDs). Accordingly, blue-emitting devices with iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C~2′] picolinate (FIrpic) as phosphorescent dopant have been fabricated and show high efficiency with low roll-off. In particular, 44.0 cd A~(-1) (41.3 lm W~(-1)) at 100 cd m~(-2) and 41.9 cd A~(-1) (32.9 lm W~(-1)) at 1000 cd m~(-2) were achieved when SSTF was used as host material; 28.1 lm W~(-1) at 100 cd m~(-2) and 20.6 lm W~(-1) at 1000 cd m~(-2) were achieved when SSTF was used as exciton-blocking layer. All of the results are superior to those of the reference devices and show the potential applicability and versatility of SSTF in blue PhOLEDs. Into the blue: Blue phosphorescent material 10-phenyl-2′-(triphenylsilyl)-10H-spiro[acridine-9,9′-fluorene] (SSTF) has been synthesized. The triphenylsilyl side group imparts good thermal stability. The energy levels of SSTF make it suitable as a host material or exciton-blocking layer in blue phosphorescent organic light-emitting diodes (see figure; PE=power efficiency).