A new class of cis-stilbene/fluorene (STIF) and 10,11-benzo- and imidazole-fused dibenzosuberane/fluorene (Bz-STIF and Imd-STIF) spiro hybrid systems with paired cyanophenyl, pyridyl, and/or pyrimidyl units was synthesized as electron transporting materials (ETMs) for blue fluorescent OLEDs (FOLEDs) and phosphorescent organic light emitting diodes (PhOLEDs). Their photophysical (UV-Vis absorption and emission), electrochemical (E /E ), morphological (glassy transition temperature, T ), and thermal stability (decomposition temperature, T ) properties are systematical compared. Their correlations regarding the effects of the fused unit/substituent(s) in the STIF core on the morphological/thermal stability, HOMO/LUMO energy level, π-electron distribution profiles by DFT calculations, and electron mobility are established.
View Article and Find Full Text PDFThis article reports for the time-resolved photophysical studies of spirally configured ( cis-stilbene) trimers and their spin-coated organic light-emitting diode (OLED) device performances. Transient absorption profiles of spirally configured, ter-( cis-stilbene) were studied by pulse radiolysis. The emission profiles after charge recombination of their incipient radical ions in benzene provides insights into the emission mechanism and efficiency in OLED devices.
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