Bipolar gold(III) complexes for solution-processable organic light-emitting devices with a small efficiency roll-off

Poster: no. 12A new class of bipolar alkynylgold(III) complexes containing triphenylamine and benzimidazole moieties has been synthesized and fully characterized. The incorporation of methyl groups in the central phenyl unit has been found to rigidify the molecule to reduce non-radiative decay, yielding a high photoluminescence quantum yield of up to 75 % in spin-coated thin films. More importantly, this class of alkynylgold(III) complexes exhibits excellent solubility in various organic solvents and is capable of serving as phosphorescent dopants in the fabrication of solution-processable organic lightemitting devices (OLEDs). Efficient solution-processable OLEDs with high external quantum efficiency (EQE) of up to 10 % and an extremely small efficiency roll-off of less than 1 % at a practical brightness of 1000 cd m–2 have been demonstrated.published_or_final_versio

Bipolar Gold(III) Complexes for Solution-Processable Organic Light-Emitting Devices with a Small Efficiency Roll-Off

Symposium S15: Metal Complexes for Optics: from fundamental to applications : no. S15.P21published_or_final_versio

Host engineering for improving the performance of blue phosphorescent organic light-emitting devices

We report an effective means to greatly improve the performance of blue phosphorescent organic light-emitting devices by doping well-known electron- or hole-transporting triplet host material, specifically, 3-(4-biphenyl)-4-phenyl- 5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ) or 4,4′,4′′- tris(N-carbazolyl)triphenylamine (TCTA), into emissive layer to form mixed host structures. A superior device performance with high current and power efficiencies of 47.4 cd/A and 37.3 lm/W, respectively, and more importantly, a theoretical maximum of external quantum efficiency of 21.9%, can be achieved for an optimized TCTA-doped device. On the other hand, doping of TAZ into hole-transporting host material would degrade device performance. It is found that, in addition to the well-known effects of charge carrier balance, both energy levels and triplet energies of mixed host materials play crucial roles in determining the device performance. As confirmed by the time-resolved phosphorescence decay studies, the lifetime of FIrpic is strongly dependent on the triplet energy of host materials and the shorter lifetime of triplet excitons with high Stern-Volmer quenching constant of 0.1564% -1 in TAZ-doped films is the origin of the low electroluminescence efficiency of the TAZ-doped devices. © 2011 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex

Optimized quality feature learning for video quality assessment

202307 bcwwAccepted ManuscriptRGCOthersCentre for Advances in Reliability and Safety (CAiRS) admitted under AIR@InnoHK Research ClusterPublishe

Quality feature learning via multi-channel CNN and GRU for no-reference video quality assessment

202307 bcwwVersion of RecordRGCPublishe

Synthesis and luminescence studies of Near-Infrared Emitting Re(I) Complexes

Poster Session: no. MS.A2.P.093A series of diimine rhenium(I) carbonyl complexes with formula [Re(CO)3(N-N)Br] where N-N = 2,2’-bipyridine modified by electron-donating groups at the 5,5’-positions has been synthesized and characterized. Their photophysical properties are studied by UV-vis and emission spectroscopies. The UV-vis spectra of these complexes show two absorption bands. The higher energy bands ranging from 335-368 nm are assigned as an admixture of ...link_to_OA_fulltex