Current-Density Dependence of Transient Properties in Green Phosphorescent Organic Light-Emitting Diodes

Efficiency phosphorescent OLEDs with a low roll-off based on a hetero-triplet iridium complex

“…Ir(ppy) 3 and Ir(ppy) 2 pbi show strong green phosphorescence with a peak maximum wavelength at 514 and 517 nm with photoluminescence quantum yield (4) of 0.40 and 0.21, respectively, calculated based on our previous report [28]. In the heterocyclometalated complex Ir(ppy) 2 pbi, the triplet MLCT state of Ir-ppy and Ir-pbi were 2.41 and 2.37 eV, respectively, estimated from the emission of Ir(ppy) 3 [14] and tris(1,2-diphenyl-1Hbenzimidazol)iridium [Ir(pbi) 3 ] [29]. Therefore the 0.04 eV difference between the triplet MLCT state of Ir-ppy and Ir-pbi was too small for the occurrence of efficient intramolecular energy transfer [30].…”

Organic light-emitting and photodetector devices for flexible optical link and sensor devices: Fundamentals and future prospects in printed optoelectronic devices for high-speed modulation

“…The cut-off frequency of the device is mainly limited by the phosphorescent recombination lifetime. PhOLEDs can be expected to be utilized as one of the light sources driven at less than 1 MHz [16]. PLEDs based on fluorene derivatives with short fluorescence lifetime, which exhibit high output power of above 30 mW/cm 2 can be expected to be applied to the electro-optical conversion devices [17].…”