• Title/Summary/Keyword: electrical & electronic engineering

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p-n Heterojunction Composed of n-ZnO/p-Zn-doped InP

  • Shim, Eun-Sub;Kang, Hong-Seong;Kang, Jeong-Seok;Pang, Seong-Sik;Lee, Sang-Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.1
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    • pp.1-3
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    • 2002
  • A p-n junction was obtained by the deposition of an n-type ZnO thin film on a p-type Zn-doped InP substrate. The Zn-doped InP substrate has been made by the diffusion of Zn with sealed ampoule technique. The ZnO deposition process was performed by pulsed laser deposition (PLD). The p-n junction was formed and showed typical I-V characteristics. We will also discuss about the realization of an ultraviolet light-emitting diode (LED). The structure of n-ZnO/p-Zn-doped InP could be a good candidate for the realization of an ultraviolet light-emitting diode or an ultraviolet laser diode.

Liquid Crystal Alignment Effect with in-situ Photoalignment on Plastic Substrates (플라스틱 기판을 이용한 in-situ 광배향법에 의한 액정배향 효과)

  • Hwang, Jeoung-Yeon;Nam, Ki-Hyung;Kim, Jong-Hwan;Kim, Kang-Woo;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.80-83
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    • 2003
  • We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with in-situ photoalignment method on polyimide (PI) surfaces using thin plastic substrates. The LC aligning capabilities and pretilt angle of the thin plastic substrates by in-situ photoalignment method were better than that of the glass substrate by general photoalignment. Also, the LC pretilt angle increased with increasing healing temperature and exposure time.

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Neural network modeling of Pretilt Angle on the Homogeneous Polyimide Surface (신경망을 이용한 공정변수에 따른 수평 폴리머 표면의 경사각에 관한 연구)

  • Lee, Jung-Hwan;Ko, Young-Don;Kang, Hee-Jin;Seo, Dae-Shik;Yun, Il-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.426-427
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    • 2006
  • In this paper, the neural network model of the pretilt angle in the nematic liquid crystal on the homogeneous polyimide surface with different surface treatments is investigated. The pretilt angle is one of the main factors to determine the alignment of the liquid crystal display. The pretilt angle is measured to analyze the variation of the characteristics on the various process conditions. The rubbing strength and the hard baking temperature are considered as input factors. Latin hypercube sampling was used to generate initial weights and biases.

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Evaluation of Low Power and High Speed CMOS Current Comparators

  • Rahman, Labonnah Farzana;Reaz, Mamun Bin Ibne;Marufuzzaman, Mohammad;Mashur, Mujahidun Bin;Badal, Md. Torikul Islam
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.6
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    • pp.317-328
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    • 2016
  • Over the past few decades, CMOS current comparators have been used in a wide range of applications, including analogue circuits, MVL (multiple-valued logic) circuits, and various electronic products. A current comparator is generally used in an ADC (analog-to-digital) converter of sensors and similar devices, and several techniques and approaches have been implemented to design the current comparator to improve performance. To this end, this paper presents a bibliographical survey of recently-published research on different current comparator topologies for low-power and high-speed applications. Moreover, several aspects of the CMOS current comparator are discussed regarding the design implementation, parameters, and performance comparison in terms of the power dissipation and operational speed. This review will serve as a comparative study and reference for researchers working on CMOS current comparators in low-power and high-speed applications.

Investigation on the Electrical Properties of Ion Implanted ZnO Thin Film (이온 주입된 ZnO 박막의 전기적 특성 연구)

  • Kang, Hong-Seong;Lim, Sung-Hoon;Chang, Hyun-Woo;Kim, Gun-Hee;Kim, Jong-Hoon;Lee, Sang-Yeol;Lee, Jung-Kun;Nastasi, Michael
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.49-50
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    • 2005
  • Nitrogen and phosphorus ions were implanted into ZnO thin film fabricated by pulsed laser deposition. ion implanted ZnO thin films were annealed from $700^{\circ}C$ to $1000^{\circ}C$ using rapid thermal annealing process. The electron concentration was changed form $10^{20}$ to $10^{18}/cm^3$. Effect of nitrogen and phosphorus in ZnO thin films was certified and the structural and optical properties of nitrogen and phosphorus doped ZnO thin films depending on concentration of nitrogen and phosphorus were investigated.

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Electrical and Optical Characteristics of Plasma Display Panel Fabricated by Vacuum In-line Sealing (진공 인라인 실장에 의해 제작된 플라즈마 디스플레이 패널의 전기적.광학적 특성)

  • Park, Sung-Hyun;Lee, Neung-Hun;Kim, Jee-Hoon;Lee, Sang-Hoon;Chun, Seog-Hwan;Chu, Soon-Nam
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.594-597
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    • 2004
  • 본 연구에서는 진공 인라인 실장 기술을 이용하여 제작한 플라즈마 디스플레이 패널(PDP)의 전기적 광학적 특성을 측정하여, 일반적인 실장 방법을 이용한 PDP의 특성과 비교 분석하였다. 본 실험에 사용된 패널은 Screen Printer를 이용한 상 하부전극과 하판 유전체, 상판 투명유전체, 격벽 및 E-Beam Evaporation 방법을 이용하여 증착한 MgO 보호막으로 이루어져 있으며, 분위기 온도 $430^{\circ}C$, Ne-Xe(4%) 400[torr]압력 하에서 실장하였다. 높은 분위기 온도로 인하여 MgO에 Crack이 발생하였으나 지속적인 연구를 진행하여 최적의 실장 조건을 확립할 수 있었다. 이러한 진공 인라인 실장 기술은 추가적인 Annealing 공정이 필요하지 않아 공정의 단축을 모색할 수 있으며, MgO의 수화를 제거함으로써 일반적인 실장 방법을 이용한 패널보다 더 우수한 전기적 광학적 특성을 얻을 수 있었다.

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Liquid Crystal Alignment on the SiC Thin Film by the Ion Beam Exposure Method

  • Park, Chang-Joon;Hwang, Jeoung-Yeon;Kang, Hyung-Ku;Kim, Young-Hwan;Seo, Dae-Shik;Ahn, Han-Jin;Kim, Kyung-Chan;Kim, Jong-Bok;Baik, Hong-Koo
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.1
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    • pp.22-24
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    • 2005
  • We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of the SiC (Silicon Carbide) thin film. The SiC thin film exhibits good chemical and thermal stability. The good thermal and chemical stability makes SiC an attractive candidate for electronic applications. A vertical alignment of nematic liquid crystal by ion beam exposure on the SiC thin film surface was achieved. The about $87{\circ}$ of stable pretilt angle was achieved at the range from $30{\circ}$ to $45{\circ}$ of incident angle. The good LC alignment is maintained by the ion beam alignment method on the SiC thin film surface at high annealing temperatures up to $300{\circ}C$.

High Performance CMOS Charge Pumps for Phase-locked Loop

  • Rahman, Labonnah Farzana;Ariffin, NurHazliza Bt;Reaz, Mamun Bin Ibne;Marufuzzaman, Mohammad
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.5
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    • pp.241-249
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    • 2015
  • Phase-locked-loops (PLL) have been employed in high-speed data transmission systems like wireless transceivers, disk read/write channels and high-speed interfaces. The majority of the researchers use a charge pump (CP) to obtain high performance from PLLs. This paper presents a review of various CMOS CP schemes that have been implemented for PLLs and the relationship between the CP parameters with PLL performance. The CP architecture is evaluated by its current matching, charge sharing, voltage output range, linearity and power consumption characteristics. This review shows that the CP has significant impact on the quality performance of CP PLLs.

The Study of High Brightness Prism Patterned LGP using Optical Simulation Analysis

  • Ok, Chul-Ho;Han, Jeong-Min;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.4
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    • pp.178-181
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    • 2007
  • We have designed high performance prism light-guide plate (LGP) in 17 inch TFT-LCD. In test result to embody high brightness BLU in case of LGP of base and upper surface with 17 inch, thickness 8 mm adding prism construct, it is superior brightness improvement than previous that of printing form about some 20% and in this course to embody actual material it succeeded prism LGP production by 17 inch injection form process.