• 한국정보디스플레이학회:학술대회논문집
• /
• 2001.08a
• /
• pp.157-158
• /
• 2001

We synthesized Bis(3-N-ethylcarbazolyl) terephthalidene(BECP) and Bis(3-N-ethylcarbazolyl) cyanoterephthalidene (BECCP) and characterized EL properties of these materials. Our device shows a strong blue emission at 472 nm with a luminance efficiency of 0.9 lm/Wat a voltage, a current density. and a brightness of 8 V, 5.7 $mA/cm^2$, and 130 $cd/m^2$, respectively.

• 한국전기화학회:학술대회논문집
• /
• 2005.04a
• /
• pp.38-38
• /
• 2005

• Journal of the Korean Electrochemical Society
• /
• v.10 no.2
• /
• pp.126-131
• /
• 2007

The durability problem of Prussian blue in non-aqueous $Li_+$-based electrolytes has been due to the degradation of the Prussian blue electrode matrix during the insertion/extraction processes by $Li_+$. In this work, we designed and synthesised the Prussian blue without reducing the electrochromic performance in non-aqueous $Li_+$-based electrolytes. Prussian blue was electrodeposited on a glass which has ITO coating, and the coating solution is a mixture solution of $FeCl_3\;and\;K_3Fe(CN)_6$ with deionized water added HCl, KCl, and LiCl, respectively. The durability of Prussian blue was evaluated by an in-situ transmittance measurement during a continuous and pulse potential cycling test, and measured by electroactive layer thickness due to evaluating the degradation.

• Journal of Information Display
• /
• v.9 no.3
• /
• pp.23-27
• /
• 2008

This paper reports that well-balanced white emission with three primary colors can be achieved with a simple white organic light-emitting diode (WOLED) structure of ITO / $\alpha$-NPD (50 nm) / $\alpha$-NPD: Btp2Ir(acac) (8 wt%, 6 nm) / $\alpha$-NPD (5 nm) / BCP (3 nm) / $Alq_3$: C545T (0.5 wt%, 10 nm) / $Alq_3$ (40 nm) / LiF (0.5 nm) / Al (100 nm). The external quantum efficiency of the device reached 3.8% at a current density (luminance) of 4.6 mA/$cm^2$ (310 cd/$m^2$), and the maximal luminance of the device reached 19,000 cd/$m^2$ at 11.5 V. The insignificant blue shift of the emitting color with an increasing current density can be attributed to the narrowing of the exciton formation zone width.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.1 s.33
• /
• pp.1-6
• /
• 2005

White light emission is very important for applying electroluminescent device to full display, backlight and illumination light source. In this letter, Multilayer molecular organic white-light-emitting device using thin nim of blue material nitro-DPVT with fluorescent dye Rubrene for an orange emission were fabricated. The basic structure of the fabricated device is a-NPD / nitro-DPVT / nitro- DPVT:Rubrene / BCP/ Alq3. Aluminum is used as the cathode material and ITO was anode material. The white light emission spectrum covers a wide range of the visible region and the Commission Internationale do I'E clairage (C.I.E.) coordinates of the emitted light was ((0.3347, 0.3515) at 14V. The turn voltage is as low as 2.5V and quantum efficiencies are $0.35\%$.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.773-776
• /
• 2002

Efficient organic white light-emitting diodes are fabricated by doping [bis(2-methyl-8-quinolinolato) (tripheny-siloxy)aluminium (III)] (SAlq), a blue-emitting layer, with a red fluorescent dye of 4-dicyanomethylene-2-methyl-6-{2-(2,3,6,7-tetrahydro-1H,5H-benzo[i,j]quinolizin-8-yl)vinyl}-4H-pyran (DCM2). The incomplete energy transfer from blue-emitting SAlq to red-emitting DCM2 enables to obtain a balanced white light-emission. A device with the structure of ITO/TPD (50 nm)/SAlq:DCM2 (30 nm, 0.5 %)/$Alq_3$ (20 nm)/LiF (0.5 nm)/AI shows emission peaks at 456 nm and 482 nm from SAlq and at 570 nm from DCM2. The white light-emitting device shows an external quantum efficiency of about 2.3 %, a luminous efficiency of about 2.4 lm/W, and the CIE chromaticity coordinates of (0.32, 0.37) at 100 cd/m^2. A maximum luminance of about 23,800 cd/m^2. is obtained at 15 V and the current density of 782 mA/cm^2.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.2
• /
• pp.389-396
• /
• 2010

In this paper, we reported the synthesis and electroluminescent properties of blue fluorescent styrylamine derivatives end-capped with a diphenylvinyl group. A new series of styrylamine derivatives have been synthesized via the Horner-Wadsworth-Emmons reaction. To explore electroluminescent properties of these molecules, multilayer organic lighte-mitting devices with the configuration of ITO/NPB/1-5 doped in MADN/Bphen/Liq/Al were fabricated. All devices exhibited blue emissions with good EL performances. Among those reported herein, the device using dopant 5 exhibited a maximum luminance of $24,000\;cd/m^2$ at 11.0 V, a luminous efficiency of 12.5 cd/A at $20\;mA/cm^2$, a power efficiency of 6.50 lm/W at $20\;mA/cm^2$, and $CIE_{x,y}$ coordinates of (x = 0.173, y = 0.306) at 8.0 V, all of which demonstrate the superiority of these materials in blue OLEDs.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.7
• /
• pp.1951-1955
• /
• 2010

A new blue light emitting anthracene derivative, 9,10-bis-(9',9'-diethyl-7'-t-butyl-fluoren-2'-yl)anthracene (BETF), has been designed and synthesized by a palladium catalyzed Suzuki cross-coupling. A theoretical calculation of the three-dimensional structure of BETF supports that it has a non coplanar structure and inhibited intermolecular interactions resulting in high luminescent efficiency and high color purity. BETF has good thermal stability with glass-transition temperature (Tg) of $131^{\circ}C$. The PL maximum of BETF in solution and film were 438 nm and 440 nm, respectively, showing pure blue emission. A multilayer device using BETF as emitting material exhibits maximum luminescence efficiency of 2.2 cd/A and a pure blue emission (Commission Internationale de L'Eclairage (CIE) coordinates of x = 0.15, y = 0.10).

• Bulletin of the Korean Chemical Society
• /
• v.27 no.10
• /
• pp.1549-1552
• /
• 2006

We report a new series of blue dopants composed of both electron donating and electron accepting moieties in one molecule, based on nalidixic acid. The EL device derived from the dopant exhibits pure blue light emission (0.15, 0.14) The current efficiency is estimated to be 3.88 cd/A at 100 $cd/m^2$, which shows remarkable enhancement, compared to that of the host itself (2.5 cd/A at 100 $cd/m^2$) under the same conditions. These results demonstrate that the incorporation of a proper guest into the host in a guest-host doped system improves not only the purity of the fluorescent blue emission but also elevates its quantum efficiency, thus improving the OLED performance.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1611-1615
• /
• 2009

We designed new anthracene-based host material to increase color purity as well as device efficiency. The new blue host, 9,10-bis(2,4-dimethylphenyl)anthracene (BDA), has highly twisted structure and wide band gap due to ortho interaction between anthracene and introduced 2,4-dimethylphenyl substituents. BDA exhibited deep blue fluorescence in solution (${\lambda}_{max}$ = 410 nm) and in solid state (${\lambda}_{max}$ = 429 nm), respectively, with the wide optical band gap (E = 3.12 eV). Blue-light-emitting OLEDs using obtained host and 2% Flu-DPAN as emitter showed 8 cd/A of high efficiency as well as high color purity [CIE coordinates = (0.15, 015)].