• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.32-38
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• 2021

We developed an inductively coupled plasma (ICP) etcher for GaN etching using a parallel plasma electrode source with a multifunctional chuck matched to it in order for the low power consumption and low process cost in comparison with the conventional ICP system with a helical-type plasma electrode source. The optimization process condition using it for the micro light-emitting diode (µ-LED) chip fabrication was established, which is an ICP RF power of 300 W, a chuck power of 200 W, a BCl₃/Cl₂ gas ratio of 3:2. Under this condition, the mesa structure with the etch depth over 1 ㎛ and the etch angle over 75° and also with no etching residue was obtained for the µ-LED chip. The developed ICP showed the improved values on the process pressure, the etch selectivity, the etch depth uniformity, the etch angle profile and the substrate temperature uniformity in comparison with the commercial ICP. The µ-LED chip fabricated using the developed ICP showed the similar or improved characteristics in the L-I-V measurements compared with the one fabricated using the conventional ICP method

• Transactions on Electrical and Electronic Materials
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• v.6 no.4
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• pp.154-158
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• 2005

Organic molecules have many properties that make them attractive for electronic applications. We have been examining the progress of memory cell by using molecular-scale switch to give an example of the application using both nano scale components and Si-technology. In this study, molecular electronic devices were fabricated with amino style derivatives as redox-active component. This molecule is amphiphilic to allow monolayer formation by the Langmuir-Blodgett (LB) method and then this LB monolayer is inserted between two metal electrodes. According to the current-voltage (I-V) characteristics, it was found that the devices show remarkable hysteresis behavior and can be used as memory devices at ambient conditions, when aluminum oxide layer was existed on bottom electrode. The diode-like characteristics were measured only, when Pt layer was existed as bottom electrode. It was also found that this metal layer interacts with organic molecules and acts as a protecting layer, when thin Ti layer was inserted between the organic molecular layer and Al top electrode. These electrical properties of the devices may be applicable to active components for the memory and/or logic gates in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.16-16
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• 2009

발광다이오드 (Light-Emitting-Diode, LED)의 균일한 전류분포, 높은 광출력 및 내부양자효율 확보를 위해서는 활성영역으로의 균일한 전류주입이 필수적이며 이를 위해서는 최적화된 전극패턴 설계가 매우 중요하다. 따라서 현재까지지도 균일한 전류확산을 위한 전극 패턴 설계에 많은 연구가 다각도로 진행되고 있으며, 전극 패턴에 따른 LED의 성능향상 또한 보고되고 있다. 전극패턴과 더불어 중요시 되는 것은 바로 전류주입에 필수적인 전극 패드이다. 최근에는 LED가 대면적화 되어감에 따라, 패드의 개수가 증가하고 그 위치에 따른 영향력 및 중요성 또한 높아지고 있다. 본 연구에서는 동일한 전극 패턴을 갖는 Planar LED에서의 전류확산 극대화를 위한 패드의 위치에 따른 전기적 및 광학적 특성에 대해 연구하였다.

• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.193-196
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• 1996

A new type of electron emitter device of chemical-vapor-deposited diamond thin film is proposed. The device is a diode of metal-insulator-insulator-semiconductor (MIS) structure consisting of an intrinsic polycrystalline diamond film as the insulator, an aluminium electrode on one side, and hydrogenated diamond surface on the other side as the p-type semconductor with negative electron affinity (NEA). Electrons will be injected and/or excited to the conduction band of intrinsic diamond layer to be emitted from the hydrogenated diamond surface of NEA.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.974-979
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• 2009

We studied solution-processed single-layered phosphorescent organic light-emitting diodes (PHOLEDs), doped with ionic salt and treated with simultaneous electrical and thermal annealing. Because the simultaneous annealing causes the accumulation of salt ions at the electrode surfaces, the energy levels of the organic molecules are bent by the electric fields due to the adsorbed ions, i.e., the simultaneous annealing can induce the proper formation of an ionic p-i-n structure. As a result, an ionic p-i-n PHOLED with a peak luminescence of over ${\sim}35,000\;cd/m^2$ and efficiency of 27 cd/A was achieved through increased and balanced carrier-injections.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.33-41
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• 2003

The optical properties of $ZnS_ySe_{1-\chi-y}:Te_{\chi}(\chi<0.08,y~0.11)$ alloys grown by molecular beam epitaxy (MBE) have been investigated by photoluminescence (PL) and PL-excitation (PLE) spectroscopy. Good optical properties and high crystal quality were established with lattice match condition to GaAs substrate. At room temperature, emission in the visible spectrum region from blue to green was obtained by varying the Te content of the ZnSSe:Te alloy. The efficient blue and green emission were assigned to $Te_1 and Te_n(n\geq2)$cluster bound excitons, respectively. Bright green (535 nm) and blue (462 nm) light emitting diodes (LEDs) have been developed using ZnSSe:Te system as an active layer. The turn-on voltage of 2.1 V in current-voltage characteristics is very small compared to that of commercial InGaN-based LEDs (>3.4 V), indicating the formation of a good ohmic contact due to the optimized p-ZnSe/p-ZnTe multi-quantum well (MQW) superlattice electrode layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.318-319
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• 2006

기존에 사용되고 있는 ITO(Indium-Tin-Oxide)의 저항보다 낮은 저항을 가지는 AZO(ZnO-Ag-ZnO) 전극을 Top emission 방식의 OLED(organic light emitting diode)에 적용하여 발광 소자를 제작하였다. AZO박막은 기존의 ITO박막이 수십 ${\Omega}$을 나타내던 것과 비교하여 $8{\Omega}$으로 매우 낮은 저항을 나타내었다. 투과율은 84%로 기존의 ITO박막과 유사한 성능을 나타내었다.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.1
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• pp.7-14
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• 2015

Recently, advances in nano-material researches have opened the door for various transparent conductive materials, which include carbon nanotube, graphene, Ag and Cu nanowire, and printable metal grids. Among them, Ag nanowires are particularly interesting to synthesize because bulk Ag exhibits the highest electrical conductivity among all metals. Here we reviewed recently-published research works introducing various devices from organic light emitting diode to tactile sensing devices, all of which are employing AgNW for a conducting material. They proposed methods to enhance the stretchability and reversibility of the transparent electrodes, and apply them to make various flexible and stretchable electronics. It is expected that Ag nanowires are applicable to a wide range of high-performance, low-cost, stretchable electronic devices.

• Journal of Information Display
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• v.7 no.1
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• pp.35-40
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• 2006

Organic light-emitting diode (OLED) display panel using the charge-pump (CP) pixel addressing scheme was fabricated, and the results show that it is applicable for information display. A CP-OLED panel with 64 ${\times}$ 64 pixels consisting of thin-film capacitors and amorphous silicon Schottky diodes was fabricated using conventional thin-film processes. The pixel drive circuit passes electrical current into the OLED cell during most of the frame period as in the thin-film transistor (TFT)-based active-matrix (AM) OLED displays. In this study, the panel was operated at a voltage level of below 4 V, and this operation voltage can be reduced by eliminating the overlap capacitance between the column bus line and the common electrode.

• Journal of Industrial Technology
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• v.16
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• pp.147-155
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• 1996

There is a considerable interest in tunable DFB-LD for their use in OFDM and coherent optical communications. In this paper, A modeling of ${\lambda}/4$-shifted tunable wavelength three electrode DFB-LD was performed considering the spatial hole burning within a laser diode cavity. The modeling will show design paramenters' requirement for high-speed and broad bandwidth lasers. The simulations of modeling prove that the continuous tuning range is about 3nm and the SMSR is about several dB. We showed that the optical power and carrier density distribution along z for several dc current with SHB. It was shown that prove that optical power and carrier density along cavity are changed and thismeans that modeling is correct.