• Title/Summary/Keyword: sterical effect

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A Study for Luminescence Properties of OLEDs Using $Alq_2-Ncd$ as an Emitting Layer ($Alq_2-Ncd$를 이용한 유기 전기 발광 소자의 발광특성에 관한 연구)

  • Yoon, Hee-Chan;Shin, Hoon-Kyu;Kim, Byoung-Sang;Kim, Chung-Kyun;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.518-521
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    • 2002
  • New luminescent material, 6,11-Dihydroxy-5,12-naphthacenedione$(Alq_2-Ncd)$ was synthesized. And extended efforts have been made to obtain high-performance electro-luminescent(EL) devices, since the first report of organic light-emitting diodes(OLEDs) based on tris-(8-hydroxy-quinoline)aluminum$(Alq_3)$ Current-voltage characteristics, brightness-voltage characteristics, luminous efficiency and quantum efficiency were measured at room temperature. The maximum wavelength of the EL is at around 504nm and the brightness is up to $2702[cd/m^2]$ with the maximum efficiency up to 3.91 [1m/W]. This study indicates not only the sterical effect but also some other effect would be responsible for the change of the emission wavelength.

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Luminescent Properties of Organic Light Emitting Diode Using $Alq_3$ Complex ($Alq_3$ 유도체를 사용한 유기전기발광소자의 발광 특성)

  • Yang, Ki-Sung;Kim, Doo-Seok;Kim, Byoung-Snag;Shin, Hoon-Kyu;Kim, Chung-Kyun;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1703-1705
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    • 2004
  • New luminescent material, 6.11-dihydoxy-5.12-naphtacene-dione $Alq_3$ complex($Alq_2$-Ncd), 1.4-dihydoxy-5.8-naphtaquinone $Alq_3$ complex ($Al_2Nq_4$) was synthesized. The $Alq_2-$ Ncd and $Al_2Nq_4$ has big molecular weight and many ${\pi}$-electrons more than widely known $Alq_3$. And extended efforts have been made to obtain high-performance electro luminescent(EL) devices. We used hole transfer layer of powdered TPD to improve hole transfer and characteristics of interface in OLED. This study indicates not only the sterical effect but also some other effects that would be responsible for the change of the emission wavelength. improvement of luminance and etc.

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Characteristics of OLEDs Using $Alq_2-Ncd\;and\;Alq_2-Nq$ as Emitting Layer ($Alq_2-Ncd$$Alq_2-Nq$를 이용한 유기전기발광 소자의 특성)

  • Yang, Ki-Sung;Shin, Hoon-Kyu;Kim, Chung-Kyun;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.447-450
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    • 2003
  • In this paper, new luminescent material, 6,11-dihydoxy-5,12-naphtacene-dione Alq3 complex (Alq2-Ncd), 1,4-dihydoxy-5,8-naphtaquinone Alq3 complex(Alq2-Nq) was synthesized. And extended efforts had been made to obtain high-performance electroluminescent(EL) devices, since the first report of organic light-emitting diodes(OLEDS) based on tris-(8-hydroxyquinoline) aluminum(Alq3). We have performed investigate characterization of the materials. Current-voltage characteristics, luminance-voltage characteristics and luminous efficiency were measured by Flat Panel Display Analysis System(Model 200-AT) at room temperature. An intensive research is going on to improve the device efficiency using the hole injection layer, different electrodes, and etc. By using the hole injection layer, the charge-injection can be controlled and the stability could be improved. This study indicates not only the sterical effect but also some other effects would be responsible for the change of the emission wavelength.

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Effect of Fatty Acid Compositions by Monoglyceride on Rheological Properties of Ice Cream (Monoglyceride의 지방산(脂肪酸) 조성(組成)이 Ice Cream 물성(物性)에 미치는 영향)

  • Cho, Young-Koo
    • Korean Journal of Food Science and Technology
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    • v.20 no.2
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    • pp.236-244
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    • 1988
  • The characteristics of ice cream, such as type-keeping viscosity, turbidity and stability of emulsion, were studied with the different composition of fatty acid of monoglyceride. The effect of saturated fatty acid of monoglycerides such as monolaurin, monomyristin, monopalmitin and monostearin on the characteristics of ice cream did not show any difference. The unsaturated fatty acid of monoglycerides, however, such as monocaprin and monoolein, was drastically enhanced the viscosity and easily happened the overrun of ice cream mixture which were resulted in the condensation of the fat droplet. Also the condensed fat droplet had the sterical network-structure. When the ratio of monostearin and monoolein becomed about 30:70, especially, it was confirmed the curdling of fat sphere increase to a maximun so that type-keeping and heat stability of ice cream were improved.

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