Film thickness influence of dual iridium complex ultrathin layers on the performance of nondoped white organic light-emitting diodes

New 2-phenyl-5-nitropyridyl containing iridium(III) cyclometalated complexes: syntheses, structures, electrochemistry and photophysical properties

“…Iridium(III) complexes have long-lived excited states and high luminescence quantum yields, mainly because of low-lying metal to ligand charge transfer (MLCT), leading to their extensive application in emission materials [7][8][9][10][11][12]. 2-Phenylpyridyl (ppy) containing iridium(III) cyclometalated complexes have been investigated sufficiently and widespreadly in the field of OLEDs, because these complexes are known to exhibit high triplet quantum yields due to mixing the singlet and the triplet excited states via spin-orbit coupling, which enhances the tripletstate subsequently, leading to high phosphorescence efficiencies.…”

High color rendering white organic light-emitting diodes fabricated using a broad-bandwidth red phosphorescent emitter for lighting applications

“…The CIE-Y values were almost constant for all the devices, whereas the CIE-X values were gradually decreased by increasing the driving voltages. The spectral stability of the fabricated WOLEDs is not perfect but comparable to other reported multilayer WOLED devices [29][30][31]. The device performances and spectral stabilities of WOLEDs fabricated in this study would be improved by further purification of materials, and also optimization of device structures.…”

Recent progress on organic light-emitting diodes with phosphorescent ultrathin (<1nm) light-emitting layers

“…In general, holes and electrons mainly recombine in the organic layer between HTL (hole transporting layer) and ETL (electron transporting layer), which is structured by doping emitters into hosts in conventional host-guest system-based OLEDs. For UEMLs-based OLEDs, instead of doping emitter, phosphorescent UEML is directly inserted into common host materials such as TCTA ( Zhao et al., 2013a ; Tao et al., 2017 ; Zhang et al., 2017a ), CBP ( Liu et al., 2013b ; Xue et al., 2015a , 2015b ), and mCP ( Tan et al., 2015 ; Xue et al., 2015c ; Wang et al., 2019a , 2020 ; Yu et al., 2011 ; Yang et al., 2018 ) etc. Some work have been carried out for investigating the spatial distribution of excitons, and further revealed the effects of the thickness and position of UEMLs on the device performance in UEMLs-based OLEDs ( Tan et al., 2015 ; Zhao et al., 2018b ).…”