• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.7
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• pp.780-790
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• 1988

We have studied the hot-carrier-induced degradation caused by the high channel electric field due to the decrease of the gate length of MOSFET used in VLSI. Under DC stress, the condition in which maximum substrate current occures gave the worst degradation. Under AC dynamic stress, other conditions, the pulse shape and the falling rate, gave enormous effects on the degradation phenomena, especially at 77K. Threshold voltage, transconductance, channel conductance and gate current were measured and compared under various stress conditions. The threshold voltage was almost completely recovered by hot-injection stress as a reverse-stress. But, the transconductance was rapidly degraded under hot-hole injection and recovered by sequential hot-electron stress. The Si-SiO2 interface state density was analyzed by a charge pumping technique and the charge pumping current showed the same trend as the threshold voltage shift in degradation process.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.30-33
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• 2002

We have shown that it is possible to form a fibrilar network of fibronectin on a polyelectrolyte polymer film whose dimensions are similar to those reported on the extra cellular matrix. The fibronectin network was observed to form only when the charge density of the polymer was in excess of the natural charge density of the cell wall. Furthermore, the self-organized fibronectin layer was much thicker than the polymer film, indicating that long ranged interaction may playa key role in the assembly process. It is therefore important to understand the structure of the polymer layer/protein interface. Here we report on a neutron reflectivity study where we explore the structure of the polyelectrolyte layer, in this case sulfonated polystyrene (PSSx,), with varying degree of sulfonation (x<30%), as a function of sulfur content and counter ion concentration. These results are then correlated with systemic study of the adsorption and the multilayer formation of fibronectin as a function of incubation time for various sulfonation levels of $PSSx.^1$

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.273-277
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• 2002

In the electrode fabrication of unit cell, we found that optimal the electrochemical characteristics were obtained with at 90 wt.% of activated carbon(BP-20), 5 wt.% of conducting agent(Ppy, Super P) and 5 wt.% of P(VdF-co-HFP)/PVP mixed binder. The electrochemical characteristics of unit cell with Ppy improver were as follows : 37.6 F/g of specific capacitance, 0.98 $\Omega$ of AC-ESR, 2.92 Wh/kg and 6.05 Wh/L of energy density, and 754 W/kg and 1,562 W/L of power density. It was confirmed that internal resistance were reduced due to the increase of electrical conductivity and filling density by the introduction of conductivity agent, and content of conducting agent was suitable in the range of 4~6 wt.%. According to the impedance measurement of the electrode with conductivity agent, we found that it was possible to charge rapidly by the fast steady-state current convergence due to low equivalent series resistance(AC-ESR), fast charge transfer rate at interface between electrode and electrolyte, and low RC time constant.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.7
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• pp.1042-1048
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• 1990

The approximations of charge relationships at normally doped semiconductor interfaces were qualitatively derived basis on electrical neutrality conditions. Effects of ion adsorptions, activation processes, interfacial structures, rectifying phenomena, and effects of surface potential barriers at the p- and n-Si/CsNO3 aqueous electrolytes, and the p-Si/(1HF:3HNO3:6H2O) electrolyte solutions were investigated using a cyclic voltammetric method. The space charge acts the most important role for the pn junction structures, the rectifying phenomena, and the activation processes. The Current-Voltage (I-V) characteristics curves significantly depend on developing of the Helmholtz double layers and charging of the show surface states during the activation processes. A linear Current-Voltage characteristics region was observed at the p-Si/(1HF:3HNO3: 6H2O) electrolyte solution interface.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.904-906
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• 2009

Organic field-effect transistor (OFET) memory is an emerging device for its potential to realize light-weight, low cost flexible charge storage media. Here we report on a solution-processed poly[9,9-dioctylfluorenyl-2,7-diyl]-co-(bithiophene)] (F8T2) nano floating-gate memory (NFGM) with top-gate/bottom-contact device configuration. A reversible shift in the threshold voltage ($V_{Th}$) and the reliable memory characteristics were achieved by incorporation of thin Au nanoparticles (NPs) as charge storage sites for negative electrons at the interface between polystyrene and cross-linked poly(4-vinylphenol).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.8
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• pp.693-699
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• 2003

To improve thermal stability of Teflon FEP which is the most widely used materials for electret application, Teflon AF film of 1 $\mu\textrm{m}$ thick was spin coated on FEP film and the charge storage properties were investigated. The surface potential depend on aging temperature. Thermal Stimulated Current(TSC), Atomic Force Microscopy(AFM), and Fourier Transform-Infrared Spectroscope(FT-lR) measurements were carried out. It is shown that the AF/FEP dual film have more higher electrical property and thermal stability than that FEP film have caused by charge stored at interface of AF and FEP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.169-172
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• 1998

We have investigates a surface pressure, a displacement current and a charge measurement by distance of between electrode 1 and water surface of organic monolayers. And the displacement current was generated during compression of Arachidic acid mono1ayers at a air-water interface. The result from our work show that the displacement current of a Langmuir(L) film for Arachidic acid monolayers has the different maximum points according to the electrode distance. We are known that the displacement current and a charge was generated in inverse proportion to electrode distance d.

• Vacuum Magazine
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• v.2 no.2
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• pp.12-16
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• 2015

Organic photovoltaics (OPVs) have attracted significant interest in an interdisciplinary research field for the decades as a next-generation photovoltaic device due to their unique advantages. One of requirements for OPVs having high power conversion efficiency is the favorable energy level alignment between the electrode/organic and organic/organic interfaces to manage the exciton dissociation and improve the charge transport. In this review, strategies to enhance the OPV performance by controlling the energy level alignment are discussed. The insertion of an exciton blocking layer leads to the efficient dissociation of photogenerated excitons at the donor/acceptor interface enhancing the short-circuit current density. The choice of a donor having a high ionization energy and an acceptor having a low electron affinity increases the open-circuit voltage. The insertion of an appropriate work function modifier which reduces the charge injection barrier removes the S-kink in current density-voltage characteristics of OPVs and improves the fill factor. This review would give a valuable guide to design the efficient OPV structure.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.360-360
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• 2010

Very initial stage of oxidation process of Si (001) surface was investigated using large scale molecular dynamics simulation. Reactive force field potential was used for the simulation owing to its ability to handle charge variation associated with the oxidation reaction. To know the detail mechanism of both adsorption and desorption of water molecule (for simulating wet oxidation), oxygen molecule (for dry oxidation) and their atom constituents, interaction of one molecule with Si surface was carefully observed. The simulation is then continued with many water and oxygen molecules to understand the kinetics of oxide growth. The results show that possibilities of desorption and adsorption depend strongly on initial atomic configuration as well as temperature. We observed a tendency that H atoms come relatively into deeper surface or otherwise quickly desorbed away from the silicon surface. On the other hand, most oxygen atoms are bonded with first layer of silicon surface. We also noticed that charge transfer is only occur in nearest neighbor regime which has been pointed out by DFT calculation. Atomic structure of the interface between the oxide and Si substrate was characterized in atomic scale.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.408-411
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• 2019

ZTO/n-Si thin film is produced to investigate tunneling phenomena by interface characteristics by the depletion layer. For diversity of the depletion layer, the thin film of ZTO is heat treated after deposition, and the gpolarization is found to change depending on the heat treatment temperature and capacitance. The higher the heat treatment temperature is, the higher the capacitance is, because more charges are formed, the highest at $150^{\circ}C$. The capacitance decreases at $200^{\circ}C$ ZTO heat treated at $150^{\circ}C$ shows tunneling phenomena, with low non-resistance and reduced charge concentration. When the carrier concentration is low and the resistance is low, the depletion layer has an increased potential barrier, which results in a tunneling phenomenon, which results in an increase in current. However, the ZTO thin film with high charge or high resistance shows a Schottky junction feature. The reason for the great capacitance increase is the increased current due to tunneling in the depletion layer.