Improving efficiency roll-off in organic light emitting devices with a fluorescence-interlayer-phosphorescence emission architecture

摘要

Organic light emitting devices (OLEDs) with a fluorescence-interlayer- phosphorescence emission layer structure (FIP EML) has been proposed to solve the efficiency roll-off issue effectively. Efficient green OLED based on FIP EML exhibiting only 26% roll-off in the luminance efficiency, which is lower than the typical roll-off of 51% for conventional phosphorescent OLEDs with single EML operated at 5-150 mA/cm2 range, has been demonstrated. Such enhancement should be attributed to the improved carrier balance, the exciton redistribution in recombination zone, the suppression of nonradiative exciton quenching processes, and the elimination of energy transfer loss offered by the FIP EML structure. © 2009 American Institute of Physics.