We report blue electrophosphorescent organic light emitting devices (OLEDs) with a new ambipolar host material, 4-(diphenylphosphoryl)-N,N-diphenylaniline (HM-A1), doped with the blue phosphor iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,C2’]picolinate (FIrpic). The ambipolar nature of the host was verified using single carrier devices. The power efficiency of devices that employed 2,8-bis(diphenylphosphoryl)dibenzothiophene (PO15) as the electron transport layer showed optimized device performance when the electron transport layer thickness was 500 Å, giving a peak power efficiency of 46 lm/W (corresponding external quantum efficiency of 17.1%). The external quantum efficiency and power efficiency at the brightness of 800 Cd/m2 were measured with no light outcoupling enhancement and found to be 15.4% and 26 lm/W, respectively.
Revised: September 1, 2010 |
Published: June 1, 2009
Citation
Polikarpov E., J.S. Swensen, N. Chopra, F. So, and A.B. Padmaperuma. 2009.An ambipolar phosphine oxide-based host for high power efficiency blue phosphorescent organic light emitting devices.Applied Physics Letters 94, no. 22:Art. No. 223304.PNNL-SA-65259.