2014/04/11 by Wenyu Ji, Ji, Wenyu, Furong Zhu +1
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Luminescence and Fluorescent Materials #Materials Science (cond-mat.mtrl-sci) #Organic Electronics and Photovoltaics #Organic Light-Emitting Diodes Research #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1404.2994
This paper has been withdrawn by the author due to a crucial data error
openalex publication_date 2014/04/11 · arxiv created 2014/10/24 · arxiv updated 2014/10/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
This work reports our effort on understanding the efficiency roll-off in blue phosphorescent organic light-emitting diodes (OLEDs), based on a blue phosphorescence from bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)- iridium (FIrpic) doped in 4,4-N,N-dicarbazole-biphenyl (CBP) host. The performance of a set of blue phosphorescent OLEDs with different FIrpic dopant concentrations was analyzed. Phosphorescent OLEDs, having a 30 nm thick pure FIrpic emissive layer, with a high luminous efficiency of 7.76 cd/A at 100 mA/cm2 was obtained. Theoretical calculation, based on the density functional theory, reveals that the exciton self-quenching process is suppressed due to the strong Coulomb repulsion between FIrpic molecules. It is found that the efficiency roll-off in FIrpic-based OLEDs is closely related to the exciton quenching induced by the CBP+ radical cations that are present in the CBP host.