Dual efficiency enhancement by delayed fluorescence and dipole orientation in high-efficiency fluorescent organic light-emitting diodes

作者：Yokoyama Daisuke^*; Park Youngil; Kim Beomjin; Kim Sookang; Pu Yong Jin; Kido Junji; Park Jongwook

来源：Applied Physics Letters, 2011, 99(12): 123303.

DOI：10.1063/1.3637608

To explain the origin of extremely high efficiencies of deep-blue fluorescent organic light-emitting diodes (OLEDs) with anisotropic-shaped anthracene derivatives, the enhancements of singlet-exciton generation efficiency and outcoupling efficiency were investigated by transient electroluminescence measurement and variable angle spectroscopic ellipsometry, respectively. Both the delayed fluorescence from singlet excitons generated via triplet-triplet annihilation and the outcoupling enhancement by dipole orientation of emitters were found to contribute to the high external quantum efficiencies of the devices. This dual efficiency enhancement is important for understanding and further improving high-performance fluorescent OLEDs.

• 出版日期2011-9-19