We report blue organic light-emitting devices with iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,C2’]picolinate (FIrpic) as an emitter doped into a series of phosphine oxide-based host materials that have significantly different charge transport properties: 4-(diphenylphosphoryl)-N,N-diphenylaniline (HM-A1), N-(4-diphenylphosphoryl phenyl) carbazole (PO12), 9-(6-(diphenylphosphoryl)pyridin-3-yl)-9H-carbazole (HM-A5), and 6-(diphenylphosphoryl)-N,N-diphenylpyridin-3-amine (HM-A6). Depending on the nature of the host material, the location of the emission zone can be moved within the emissive layer from the hole transport layer interface to the electron-transport layer interface. The charge transport properties of the materials were evaluated using single carrier devices.
Revised: June 1, 2011 |
Published: February 1, 2010
Citation
Polikarpov E., J.S. Swensen, L. Cosimbescu, P.K. Koech, J.E. Rainbolt, and A.B. Padmaperuma. 2010.Emission Zone Control in Blue Organic Electrophosphorescent Devices Through Chemical Modification of Host Materials.Applied Physics Letters 96, no. 5:Art. No. 053306.PNNL-SA-68607.doi:10.1063/1.3298556