High-Efficiency Red-Light Emission from Polyfluorenes Grafted with Cyclometalated Iridium Complexes and Charge Transport Moiety

2003 ◽  
Vol 125 (3) ◽  
pp. 636-637 ◽  
Author(s):  
Xiwen Chen ◽  
Jin-Long Liao ◽  
Yongmin Liang ◽  
M. O. Ahmed ◽  
Hao-En Tseng ◽  
...  
Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2976
Author(s):  
Konstantinos Andrikopoulos ◽  
Charalampos Anastasopoulos ◽  
Joannis K. Kallitsis ◽  
Aikaterini K. Andreopoulou

In this work, hybrid polymeric bis-tridentate iridium(III) complexes bearing derivatives of terpyridine (tpy) and 2,6-di(phenyl) pyridine as ligands were successfully synthesized and evaluated as red-light emitters. At first, the synthesis of small molecular bis-tridendate Ir(III) complexes bearing alkoxy-, methyl-, or hydroxy-functionalized terpyridines and a dihydroxyphenyl-pyridine moiety was accomplished. Molecular complexes bearing two polymerizable end-hydroxyl groups and methyl- or alkoxy-decorated terpyridines were copolymerized with difluorodiphenyl-sulphone under high temperature polyetherification conditions. Alternatively, the post-polymerization complexation of the terpyridine-iridium(III) monocomplexes onto the biphenyl-pyridine main chain homopolymer was explored. Both cases afforded solution-processable metallocomplex-polymers possessing the advantages of phosphorescent emitters in addition to high molecular weights and excellent film-forming ability via solution casting. The structural, optical, and electrochemical properties of the monomeric and polymeric heteroleptic iridium complexes were thoroughly investigated. The polymeric metallocomplexes were found to emit in the orange–red region (550–600 nm) with appropriate HOMO and LUMO levels to be used in conjunction with blue-emitting hosts. By varying the metal loading on the polymeric backbone, the emitter’s specific emission maxima could be successfully tuned.


2000 ◽  
Vol 638 ◽  
Author(s):  
K. Sato ◽  
T. Izumi ◽  
M. Iwase ◽  
Y. Show ◽  
S. Nozaki ◽  
...  

AbstractWe have fabricated the electroluminescence (EL) device using silicon (Si) nanocrystals, which were formed on Si substrate by co-sputtering of Si and silicon dioxide (SiO2). By treating with the Si nanocrystals in the hydrofluoric (HF) acid solution, the SiO2 region of the luminous layer reduced, and then, the electrons were efficiently injected in the Si nanocrystals. At the same time, Pb-center (non-radiative recombination center) was decreased by hydrogen termination to the Si-dangling bond in the interface between the Si nanocrystals and the SiO2 layer From these effects of the HF treatment, the high efficiency red light emission with the external quantum efficiency (EQE) of 0.35 % was obtained from the HF treated EL device under the operating voltage of +4.5 V.


2021 ◽  
Vol 186 ◽  
pp. 109025
Author(s):  
João Humberto Dias Campos ◽  
Meiry Edivirges Alvarenga ◽  
Maykon Alves Lemes ◽  
José Antônio do Nascimento Neto ◽  
Freddy Fernandes Guimarães ◽  
...  

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Hiromi Nakano ◽  
Shota Ando ◽  
Konatsu Kamimoto ◽  
Yuya Hiramatsu ◽  
Yuichi Michiue ◽  
...  

We prepared four types of Eu2O3- and P2O5-doped Ca2SiO4 phosphors with different phase compositions but identical chemical composition, the chemical formula of which was (Ca1.950Eu3+0.013☐0.037)(Si0.940P0.060)O4 (☐ denotes vacancies in Ca sites). One of the phosphors was composed exclusively of the incommensurate (IC) phase with superspace group Pnma(0β0)00s and basic unit-cell dimensions of a = 0.68004(2) nm, b = 0.54481(2) nm, and c = 0.93956(3) nm (Z = 4). The crystal structure was made up of four types of β-Ca2SiO4-related layers with an interlayer. The incommensurate modulation with wavelength of 4.110 × b was induced by the long-range stacking order of these layers. When increasing the relative amount of the IC-phase with respect to the coexisting β-phase, the red light emission intensity, under excitation at 394 nm, steadily decreased to reach the minimum, at which the specimen was composed exclusively of the IC-phase. The coordination environments of Eu3+ ion in the crystal structures of β- and IC-phases might be closely related to the photoluminescence intensities of the phosphors.


2015 ◽  
Vol 3 (30) ◽  
pp. 15372-15385 ◽  
Author(s):  
Yu-Che Hsiao ◽  
Ting Wu ◽  
Mingxing Li ◽  
Qing Liu ◽  
Wei Qin ◽  
...  

Polarization and spin-dependent excited states and charge transport.


2021 ◽  
Vol 119 (24) ◽  
pp. 241103
Author(s):  
Miao Wang ◽  
Yu Lin ◽  
Jue-Min Yi ◽  
De-Yao Li ◽  
Jian-Ping Liu ◽  
...  

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