RESUMEN
New deep blue emitting materials 2,8-bis(3,5-diphenylphenyl)-6,6,12,12-tetraethyl-6,12-dihydrodiindeno[1,2-b:1',2'-e]pyrazine (DPP-EPY) and 2,8-bis(3',5'-diphenylbiphenyl-4-yl)-6,6,12,12-tetraethyl-6,12-dihydrodiindeno[1,2-b:1',2'-e]pyrazine (DPBP-EPY) were synthesized through introduction of m-terphenyl or triphenylbenzene bulky side groups in a new indenopyrazine core. These materials all showed high thermal stability and highly reduced intermolecular interaction. DPP-EPY and DPBP-EPY showed PL maxima of 456 nm and 460 nm in deep blue region and narrow PL spectra with full-width at half-maximum (FWHM) of 46 nm and 52 nm, respectively. As a result of making non-doped OLED devices using these synthesized materials as emitting layers, DPP-EPY showed EL spectrum of 452 nm, very narrow FWHM of 46 nm, luminance efficiency of 1.04 cd/A with current density of 10 mA/cm2 and CIE coordinate of (0.161, 0.104), creating a deep blue OLED close to the National Television System Committee (NTSC) blue standard.
RESUMEN
The correlation between the molecular conformations and the electroluminescent properties of fully substituted ethylene derivatives has been studied with semiempirical molecular orbital calculations. It was found that the existence of intramolecular interactions between anthracenes in (Z)-form isomers lower their energies. UV-visible spectra were also predicted by configuration interaction calculations, and compared with experimental results.
RESUMEN
A novel core material, indenopyrazine, has been substituted with ethyl, phenyl, tolyl or fluorenyl groups on the locations 6 and 12, to newly synthesize four blue-emitting materials for OLED. Their electro-optical properties were compared through UV-Vis absorption, PL spectra and cyclic voltammetry, according to substituents of the core system of indenopyrazine. Non-doped OLED devices were fabricated by using the synthesized materials as emitting material layers, and among them, SF-EPY showed a highly-efficient luminescence with EL spectrum of 458 nm, luminous efficiency of 2.62 cd/A and CIE coordinates of (0.152, 0.142) at a current density of 10 mA/cm2.
RESUMEN
In this study, a novel moisture getter was fabricated from a new desiccant triethylaluminum [TEA] and a porous material poly(1-trimethylsilylpropyne) [PTMSP] as a binder and then was applied to organic light-emitting diode (OLED). After forming a film of 1.5 cm x 2.0 cm with 50 mg of PTMSP by a film-casting method, its property was measured. As a result, PTMSP (Mn:50 K) created a film with a relatively high porosity. PTMSP (60%) and TEA (40%) were mixed to fabricate a getter system with a good transmittance of over 80%. The fabricated getter, adopted in a OLED device, showed excellent features, as a level of commercialization: 490-hour shelf lifetime under the conditions of 60 degrees C and 90% RH.
RESUMEN
Herein, we describe the molecular electronic structure, optical, and charge-transport properties of anthracene derivatives computationally using density functional theory to understand the factors responsible for the improved efficiency and stability of organic light-emitting diodes (OLEDs) with triphenylamine (TPA)-substituted anthracene derivatives. The high performance of OLEDs with TPA-substituted anthracene is revealed to derive from three original features in comparison with aryl-substituted anthracene derivatives: 1) the HOMO and LUMO are localized separately on TPA and anthracene moieties, respectively, which leads to better stability of the OLEDs due to the more stable cation of TPA under a hole majority-carrier environment; 2) the more balanceable hole and electron transport together with the easier hole injection leads to a larger rate of hole-electron recombination, which corresponds to the higher electroluminescence efficiency; and 3) the increasing reorganization energy for both hole and electron transport and the higher HOMO energy level provide a stable potential well for hole trapping, and then trapped holes induce a built-in electric field to prompt the balance of charge-carrier injection.
RESUMEN
Deep blue emitting materials with a new core structure containing indenopyrazine have been synthesized; a non-doped device using one of these materials as a blue emitter was found to exhibit high external quantumn efficiency of 4.6% and excellent color purity of (0.154, 0.078) as well as narrow emission band of 47 nm FWHM.
RESUMEN
As a new fluoranthene derivative, a synthesis of benzo[k]fluoranthene was suggested, so new blue emitting materials, 7,12-diphenylbenzo[k]fluoranthene [DPBF] and 7,8,10-triphenylfluoranthene [TPF] were synthesized. PLmax values of both compounds showed the wavelengths of 458 nm (TPF) and 434 nm, 453 nm (DPBF) that are in blue region. ELmax wavelength of the device using DPBF as an emitting layer was 436 and 454 nm in the deep-blue region, which are similar values with PL. The device that used DPBF as an emitting layer showed high efficiency of 2.11 cd/A and the excellent color coordinate value of (0.161, 0.131) in deep-blue region.
RESUMEN
We synthesized a new HIL and HTL materials by using phenothiazinly moiety, 1,4-diphenothiazyl-benzene [DPtzB], 3',7',3",7"-tetrakis(N-phenyl-2-naphthylamine)-1,4-diphenothiazyl-benzene [PNA-DPtzB]. Synthesized materials exhibited high T(g) in the range of 175-202 degrees C. These values are much better than commonly used hole transporting materials (2-TNATA and NPB). The OLED device that used DPtzB as a HIL showed the highest efficiency of 4.31 cd/A at 10 mA/cm2.
RESUMEN
This paper reports a new HTL material that has high glass-transition temperatures (Tg) and excellent thermal properties. The synthesized material was N,N-diethyl-3,3'-bicarbazyl (DEBC), N,N-diphenyl-3,3'-bicarbazyl (DPBC) and N,N-dinaphthyl-3,3'-bicarbazyl (DNBC). The device that used DPBC as HTL showed the highest efficiency of 4.95 cd/A and 2.22 lm/W at 10 mA/cm2. This is an improvement by more than 10% from the luminance efficiency of NPB, a commercialized material.