Impacts of degradation on annihilation and efficiency roll-off in organic light-emitting devices

Abstract

Efficiency roll-off and intrinsic luminance degradation are two of the primary limitations of organic light-emitting devices (OLEDs). While both phenomena have been studied separately in detail, they are rarely considered together. Previous analyses of OLED degradation have largely neglected changes in efficiency roll-off and bimolecular quenching, and the magnitude of these changes and their impact on device lifetime remains unclear. We present experimental and modeling results to quantify the magnitude of these changes, which we find range from ~2% to above 10% in magnitude and increase in importance at high brightness or in devices with significant exciton-exciton annihilation.