• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1199-1202
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• 2007

The improvement of the electron injection is of critical importance for obtaining efficient and stable organic light-emitting diodes(OLEDs). Here, we report some of our recent results on the development of new cathode interlayer materials for OLEDs. Some of our new materials show performance superior to that of LiF.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.428-430
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• 2008

We demonstrated high power efficiency and long lifetime for organic light-emitting diode (OLED) using a new electron transport material (ETM-1). A power efficiency of the device with ETM-1 was improved compared to a standard device using tris(8-hydroxy-quinolinate)aluminum ($Alq_3$). Moreover, the lifetime was 4 times longer than the standard device.

• International Journal of Internet, Broadcasting and Communication
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• v.4 no.2
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• pp.22-27
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• 2012

The design characteristics of circular vertical-cavity surface-emitting lasers are studied by using a newly developed equivalent network. Optical parameters, such as the stop-band or the reflectivity of periodic mirrors and the resonance wavelength, are explored for the design of these structures. To evaluate the differential quantum efficiency and the threshold current density, a transverse resonance condition of modal transmission-line theory is also utilized. This approach dramatically reduces the computational time as well as gives an explicit insight to explore the optical characteristics of circular vertical-cavity surface-emitting lasers (VCSELs).

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1404-1407
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• 2005

We have fabricated organic light-emitting diodes using poly(N-vinylcarbazole)(PVK) doped with N,N'- diphenyl-N,N'-bis(3-methylphenyl)-[l,l'-biphenyl]- 4,4/-diamine (TPD) as the hole transport layer. TPD molecules act as the trapping sites in PVK and reduce the hole mobility, which can enhance the electronhole balance in the emitting layer, resulting in the enhanced device performance. We have found the optimum ratio of TPD to PVK for the EL efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.156-156
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• 2010

We have developed highly efficient blue phosphorescent organic light-emitting devices (OLED) with simplified architectures using blue phosphorescent material. The basis device structure of the blue PHOLED was anode / emitting layer (EML) / electron transport layer (ETL) / cathode. The dopant was partially doped into the host layer for investigating recombination zone, current efficiency, and emission characteristics of the blue PHOLEDs.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.261-264
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• 2000

Organic light emitting diodes(OLEDs) have been expected to find an application as a new type of display since C. W. Tang and VanSlyke first reported on high performance OLEDs. This paper has been stuied a green organic EL device using dye doped emitting layer such as C6(Coumarin 6). In the Alq-based e]ectroluminescence diodes, we applied highly fluorescent molecular(Coumarin 6) and obtained enhancement in the electroluminescence efficiency.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.37-40
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• 2000

This paper has been studied on characteristics of organic light-emitting device with various cathode materials. These catode materials were Al：Li(5%), Al, Cu, CsF/Al. And in these devices, HTL(hole transfer layer) was TPD and EML(emitting layer) was Alq$\sub$3/. We studied the I-V characteristics for each device. And then, the turn-on voltage of device for Al-Li(5%), Al, Cu, CsF/Al cathode were 7, 9, 13, 3V respectively. So, the CsF/Al cathode is superior to other cathode materials for I-V characteristics.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.172-173
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• 2004

Recently there has been many understood the basis device physics OLEDs and their basic operating principle. We demonstrate that there have many relation in order to improve luminescence efficiency both emitting light material physics characteristics and luminary. Efficient Electro Luminescence from organic materials was first reported in 1987 at Kodak. OLEDs emitting light material use tris-(8-hydroxyquinoline)(Alq3). Sudied maximum luminescence efficiency about structure of optimized emitting light layer of OLED which do observing change of luminescence efficiency by structure change of organic material in this paper.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.137-140
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• 2005

Organic light emitting transistors (OLET) which are vertically combined with the organic static induction transistor (OSIT) and organic light emitting diode (OLED) are fabricated and the device characteristics are investigated. High luminance modulations by relatively low gate voltages are obtained. In order to realize the flexible electronic circuits and displays, we have fabricated OSIT on plastic substrates. The OSIT fabricated on plastic substrate show almost same characteristics comparing with those of nonflexible OSIT on glass substrate. The OLET described here is a suitable element for flexible sheet displays.

• Transactions on Electrical and Electronic Materials
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• v.6 no.3
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• pp.97-100
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• 2005

Dynamic response of organic light-emitting diodes were analyzed in $ITO/Alq_3$(100 nm)/Al device structure with a variation of voltage an frequency. At low frequency region, complex impedance is mostly governed by resistive component, and at high frequency region by capacitive component. Also, we have evaluated resistance, capacitance and permittivity of devices.