High-performance phosphorescent organic light emitting devices with reduced efficiency roll-off at ultrahigh current densities were realized. The devices were Ir (ppy)3 -based phosphorescent organic light emitting diodes that employed 1,3-bis[2-(2, 2′ -bipyridine-6-yl)-1,3,4-oxadiazo-5-yl]benzene as a high mobility electron transfer layer. The device's brightness was enhanced while the efficiency roll-off was reduced. The device exhibits high current efficiency (21 cdA) at high brightness (80 000 cd m2), with a maximum luminescence of 136 000 cd m2 at over 1 A m2 (with an efficiency of 13 cdA). This reduction in efficiency roll-off is attributed to the suppression of the triplet-polaron quenching rate through balancing the charge carrier ratio in the device.
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- Physics and Astronomy (miscellaneous)