• Transactions on Electrical and Electronic Materials
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• v.3 no.4
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• pp.32-35
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• 2002

In this work, we test electrode material of TFD (Thin Film Diode) device subject to flexible substrate. Al, that is ductile metal, was proper for flexible electrode to fabricate flexible display. The fabricated devices had symmetric electrode structure on both sides of insulation layer. The electrode was made of ductile Al so as to reduce the mismatch of properties between the electrode and substrate. The TFD device was successfully fabricated applying our own etch-free process. Electrical properties were improved by post-annealing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.73-76
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• 2002

박막 다이오드의 전기적 특성에 미치는 전극 구조의 영향을 관찰하였다. 박막 다이오드는 하부전극-절연층($Ta_{2}O_{5}$)-상부전극의 3층 구조로 설계 및 제작하였고, 하부 전극으로 Ta, 상부 전극으로 Cr 및 Ti를 각각 사용하였다. Cr을 상부 전극으로 사용한 결과 비대칭비가 1.8인 높은 비대칭 특성을 나타내었다. 그러나 Ti 상부 전극의 경우 반대의 경향을 나타내었다. 이들을 각각 $150^{\circ}C$에서 열처리한 결과 Cr 상부 전극 다이오드는 비대칭비가 1.4로 여전히 비대칭 경향을 나타내었으나, Ti 상부 전극의 박막 다이오드는 비대칭비가 1.1로 대칭에 가까운 우수한 특성을 나타내었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.897-902
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• 1998

We prepared Organic LED with a two layer structure by vacuum evaporation. The diode consisted of hole transfer layer (thickness of 30, 50, 70 nm) and electron transfer layer (thickness of 70, 50, 30 nm) material, which was N, N'-diphenyl- N, N'-bis-(3-methyl phenyl)-1,1'-diphenyl-4,4'-diamine)(TPD) and tris(8-hydroxy quinoline) aluminum(Alq3), respectively. We investigated EL properties of the LED with various thickness and cathode electrode. The best results were obtained when thickness of the electron layer is equal to that of emission layer and when AlLi alloy was used as a cathode. The EL intensity, luminance and efficiency of organic LED with equal of layer thick were improved seven, three and two times, respectively. Alq3 was ionized by carrier injection from cathode and could produce exitons. After electron-hole pairs were formed by combination of the electrons and holes at the emission layer, Alq3 layer emitted light.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.421.2-421.2
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• 2014

We report on the growth of ZnO nanorods (NRs) grown on graphite and silicon substrates via an all-solution process and characteristics of their heterojunctions. Structural investigations indicated that morphological and crystalline properties were not significantly different for the ZnO NRs on both substrates. However, optical properties from photoluminescence spectra showed that the ZnO NRs on graphite substrate contained more point defects than that on Si substrate. The ZnO NRs on both substrates showed typical rectification properties exhibiting successful diode formation. The heterojunction between the ZnO NRs and the graphite substrate showed a Schottky diode characteristic and photoresponse under ultraviolet illumination at a small reverse bias of -0.1 V. The results showed that the graphite substrate could be a good candidate for a Schottky contact electrode as well as a conducting substrate for electronic and optoelectronic applications of ZnO NRs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.882-885
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• 2004

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 nanoscale components and Si-technology. In this study, molecular electronic devices were fabricated with amion style derivatives as redox-active component to compare to the devices using Zn-Porphyrin derivatives. 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 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. Diode-like characteristics were measured only, when Pt layer was existed as bottom electrode. It was also found that this metal layer interacts with the organic molecules and acts as a protecting layer, when thin Ti layer was inserted between the organic molecular layer and the top Al electrode. These electrical properties of the devices may be applicable to active components for the memory and/or logic gates in the future.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.148-153
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• 2003

Electron transfer through an Langmuir-Blodgett(LB) monolayer film sandwiched between metal electrodes. We used an eicosanoic acid material and the material was very famous as a thin film insulating material. Eicosanoic acid monolayer was deposited by Langmuir-Blodgett(LB) technique and a subphase was a $CdCl_2$ solution as a 2${\times}10^{-4}$ mol/L. Also we used a bottom electrode as an Al/$Al_2O_3$ and a top electrode as a Al and Ti/Al. Here, the $Al_2O_3$ on the bottom electrode was deposited by thermal evaporation method. The $Al_2O_3$ layer was acted on a tunneling barrier and insulating layer in tunnel diode. It was found that the proper transfer surface pressure for film deposition was 25 mN/m and the limiting area per molecule was about 24 ${\AA}^2$/molecule. When the positive and negative bias applied to the molecular device, the behavior shows that a tunnel switching characteristics. This result were analyzed regarding various mechanisms.

• Toxicological Research
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• v.24 no.3
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• pp.227-233
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• 2008

To detect lead ions using electrochemical voltammetric analysis, Infrared Photo-Diode Electrode(IPDE) was applied via cyclic and square wave stripping voltammetry. Lead ions were deposited at 0.5 V(versus Ag/AgCl) accumulation potential. Instrumental measurements systems were made based on a simple and compact detection system. The stripping voltammetric and cyclic voltammetric optimal parameters were searched. The results yielded a cyclic range of $40{\sim}240mgl^{-1}$ Pb(II) and a square wave stripping working range of $0.5{\sim}5.00mgl^{-1}$ Pb(II). The relative standard deviation at 2 and 4 $mgl^{-1}$ Pb(II) was 0.04% and 0.02%(n=15), respectively, using the stripping voltammetric conditions. The detection limit was found to be 0.05 $mgl^{-1}$ with a 40 sec preconcentration time. Analytical interference ions were also evaluated. The proposed method was applied to determine lead ions in various samples.

• 전자공학회논문지 IE
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• v.46 no.3
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• pp.1-5
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• 2009

In this paper, we study the electrical characteristics of $RuO_2$/n-GaN Schottky diodes fabricated by using electrochemical metallization. The solution for GaN Schottky electrodes of $RuO_2$ is perchloric acid($HClO_4$). Thickness of $RuO_2$ layer depend on supplied voltage and dipping time. We verified the possibility of the rectifying and non-rectifying devices' electrode which was depend on the thickness of $RuO_2$ layer.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.7
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• pp.774-779
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• 1988

The homo and hetero-junction diodes were fabricated using BP-Si structure. After removal of Si substrates, schottky diodes were fabricated on the BP bulk. The electrical properties of the diode were examined through current-voltage characteristics curve. The schottky diode with Sb electrode has a cut-in voltage of 0.33V. This value is almost equal to that of the typical schottky diodes. The breakdown voltage of the schottky diode is 30V. When BP was used for photo cell as a window, the conversion efficiency improved from 6.5% to 8.3%, and optical transmissivity of BP invreased in short wavelength region.

• ETRI Journal
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• v.35 no.4
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• pp.603-609
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• 2013

In this paper, we present a 600-V reverse conducting insulated gate bipolar transistor (RC-IGBT) for soft and hard switching applications, such as general purpose inverters. The newly developed RC-IGBT uses the deep reactive-ion etching trench technology without the thin wafer process technology. Therefore, a freewheeling diode (FWD) is monolithically integrated in an IGBT chip. The proposed RC-IGBT operates as an IGBT in forward conducting mode and as an FWD in reverse conducting mode. Also, to avoid the destructive failure of the gate oxide under the surge current and abnormal conditions, a protective Zener diode is successfully integrated in the gate electrode without compromising the operation performance of the IGBT.