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Improved efficiency of blue phosphorescence organic light‐emitting diodes with irregular stepwise‐doping emitting layers
Author(s) -
Liu Jun,
Wang Jing,
Huang Saijun,
Chen HsiAn,
He Gufeng
Publication year - 2013
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201228727
Subject(s) - phosphorescence , phosphorescent organic light emitting diode , doping , materials science , optoelectronics , oled , diode , quenching (fluorescence) , quantum efficiency , exciton , fluorescence , optics , nanotechnology , physics , layer (electronics) , quantum mechanics
We demonstrate highly efficient blue phosphorescence organic light‐emitting diodes (PHOLED) with irregular stepwise‐doping emitting layers (EMLs). High efficiency is realized by inserting a high‐doping EML between two relatively low‐doping EMLs. Peak luminous efficiency and power efficiency of 19.2 cd A −1 and 18.0 lm W −1 are achieved, while those of a continuous stepwise‐doping device are 9.8 cd A −1 and 8.6 lm W −1 . The dramatic efficiency enhancement is mainly attributed to the high hole–electron recombination probability and suppressed triplet excitons quenching by fine tuning the doping concentrations in the EMLs.