• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.270-270
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• 2010

OLED device is one of the most attractive and alternative display components, which stems primarily from the self-emission, large intrinsic viewing angle, and fast switching speed. However, because of its relatively short history of development, much remains to be studied in terms of its basic device physics, manufacturing processes, and reliability etc. Especially among several issues, it should be noted that the device characteristics are very sensitive to the surface properties of transparent conducting oxide (TCO) electrode materials. In this study, we have investigated the performance of OLED devices as a function of sheet resistance and surface roughness of TCO thin films. For this purpose, ITO and IZO thin films were deposited by r. f. magnetron sputtering under various ambient gases (Ar, Ar+O2 and Ar+H2, respectively). The crystal structure and surface morphology were examined by using XRD and FESEM. Also, electrical and optical properties were Investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.275-276
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• 2005

Organic Light Emitting Diodes(OLEDs) are attractive as alternative display components because of their relative merits of being self-emitting, having large intrinsic viewing angle and fast switching speed. But because of their relatively short history of development, much remains to be studied in terms of their basic device physics and design, manufacturing techniques, stability and so on. We invested electrical properties of N,N-diphenyl-N,N bis (3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD) and tris-8-hydroxyquinoline aluminum($Alq_3$) when their thicknesses were changed variedly from 3:7 to 7:3 of their thickness ratios. And we also studied properties of OLEDs depend on their deposition rate between 0.05$\sim$0.2 [nm/s].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.74-75
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• 2005

Organic Light Emitting Diodes are attractive as alternative display components because of their relative merits of being self-emitting, having large intrinsic viewing angle and fast switching speed. But because of their relatively short history of development, much remains to be studied in terms of their basic device physics and design, manufacturing techniques, stability and so on. We invested electrical properties of N, N-diphenyl-N, N bis (3-methyphenyl)-1, 1'-biphenyl-4, 4'-diamine and tris-8-hydroxyquinoline aluminum when their thickness were changed variedly from 3:7 to 7:3 of their thickness ratios. And we also studied their optimal thickness respectively.

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.23-29
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• 2011

Bistable chiral splay nematic liquid crystal display (BCSN LCD) is a memory type liquid crystal display using splay and $-\pi$ twist states as two stable states. When the cell thickness to pitch (d/p) ratio is 0.25, splay and $-\pi$ twist states have permanent memory time. However, when the transition from $-\pi$ twist state to splay state is caused by a fringe field, pixel regions show that the splay state is not perfect, but rather includes a contribution from the $-\pi$ twist state. In this paper, we propose a reflective BCSN LCD using $-\pi$ twist state in which the two stable states do not coexist. The fabricated reflective BCSN LC cell shows a high contrast ratio of over 30:1 and response times of 950 ms and 450 ms in vertical and fringe field switching, respectively. The proposed cell also shows wide viewing angle characteristics of $180^{\circ}$ in left- and right directions.