High luminance phosphorescent organic light emitting diodes based on Re(I) complex

Abstract

A novel Re(I) complex with the acenaphtho[1,2-b]pyrazino[2,3-f][1,10]phenanthroline (APPT) ligand Re(APPT)(CO)₃Br (abbreviated as Re-APPT) was used to fabricate organic light emitting diodes (OLEDs). From the electroluminescence (EL) spectra of the device at different bias voltages, it could be found that the EL maxima shifted approximately 30 nm. For OLEDs with 5% Re-APPT doped emissive layer, turn-on voltage of 6 V, maximum luminance of 7631 cd/m² and a current efficiency up to 2.36 cd/A were obtained. We suppose that a direct charge trapping took the dominant position in the EL process. Trapping contributed mostly to this relatively higher luminance.