Jee Hyun Seong

Abstract It is well known that the weight of the structural system for a high‐rise building to resist lateral loads increases in nonlinear fashion with increase in building height and slenderness ratio. For a given building height or slenderness ratio, the weight of the structural system for a high‐rise building subjected to lateral loads depends on the degree of stiffness of the building structure. Therefore, at the final stage of the structural design process, it has been a challenge to struct

We have demonstrated red-green-blue emissive white organic light-emitting diodes (RGB-WOLEDs) by using two emissive materials as dopant, 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi) and heteroleptic tris-cyclometalated iridium(III) complexes. It was found that the heteroleptic iridium complexes, bis(2-phenylquinoline)(2-p-tolylpyridine) iridium(III) [Ir(pq)2(tpy)] and bis(2-p-tolylpyridine)(2-phenylquinoline) iridium(III) [Ir(tpy)2(pq)], used in this study showed double emissive co

Abstract Herein, we present an efficient method for the high-precision automatic 3D scanning of unknown objects for mechanical parts. Our method comprises two phases, namely a rough initial scan and a precision scan. The goal of the rough initial scan is to scan the rough shape rapidly and to provide scan data for the precision scan, thereby reducing the duration of the entire process. Researchers have attempted to provide rough information regarding an object before precision scanning, e.g. by

Novel red phosphorescent heteroleptic tris-cyclometalated iridium complex, Ir(ppy)2(dpq-3F) based on 2-phenylpyridine (ppy) and 2-(3-fluorophenyl)-4-phenylquinoline (dpq-3F) ligands have been synthesized and characterized for the application in organic light-emitting diodes (OLEDs). The heteroleptic tris-cyclometalated iridium complex leads to a significant improvement in a luminous efficiency at high currents to avoid the T–T annihilation by the exciton transfer from two ppy ligands to one lumi

Novel red-emitting electrophosphorescent devices were fabricated by doping an Ir complex, Ir(tpq)2(acac), based on 2,3,4-triphenylquinoline (tpq) ligand. The EL spectrum of the device showed emission maximum peak at 611 nm and CIE coordinates of that were (0.664, 0.332) at 12 V, respectively, due to long conjugation length of Ir(tpq)2(acac). The luminance of the device with Ir(tpq)2(acac) was 4160 cd/m2 at 14 V. The maximum luminous efficiencies and power efficiency of the device with Ir(tpq)2(a

We demonstrated that the simple layered red phosphorescent organic light-emitting diodes (OLEDs) are possible to have high efficiency, low driving voltage, stable roll-off efficiency, and pure emission color without hole injection and transport layers. We fabricated the OLEDs with a structure of ITO/CBP doped with Ir(pq)2(acac)/BPhen/Liq/Al, where the doping concentration of red dopant, Ir(pq)2(acac), was varied from 4% to 20%. As a result, the quantum efficiencies of 13.4, 11.2, 16.7, 10.8 and

We demonstrated that single-layered red phosphorescent organic light-emitting diodes (OLEDs) can have high a efficiency without carrier transport and injection layers. This high efficiency is caused by the direct injection of carriers from electrodes into a dopant, bis(2-phenylquinoline) iridium(III) (acetylacetonate) [Ir(ppy) 2 (acac)]. This mechanism is proved by analyzing the single-layered devices with various hosts, 4,4'- N , N '-dicarbazole-biphenyl (CBP), 9-phenyl-3-[4-(1-phenyl-1 H -benz

We developed a novel carbazole-type material, 9-phenyl-3,6-bis(4-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl)-9H-carbazole (LPGH 153), and fabricated the green and red phosphorescent organic light-emitting diodes (OLEDs) using LPGH 153 as host. The red and green devices have the max. luminous efficiencies of 22.2 cd/A and 32.2 cd/A, respectively.

Abstract New heteroleptic tris-cyclometalated iridium complex having two different (C∧N) ligands, [Ir(dpq)2(dpq-3F)] (dpq = 2,4-diphenylquinoline, dpq-3F = 2-(3′-fluorophenyl)-4-phenylquinoline), have been synthesized and characterized for an efficient red organic light-emitting diodes (OLEDs). The iridium phosphors emit bright red light with its maximum at 608 nm. The heteroleptic tris-cyclometalated iridium complex [Ir(dpq)2(dpq-3F)] is shown to be a more efficient electrophosphor than the hom