• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.2
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• pp.53-61
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• 2004

Characteristics of half cells of graphite/lithium and LiCoO$_2$/lithium, and full cells of graphite/LiCoO$_2$/ were analyzed by the use of GISOC(the gradual increasing of the state of charge). GISOC analyses generated IIE(the initial intercalation efficiency), which represents lithium intercalation property of the electrode material, and IIC$_{s}$(the initial irreversible capacity by the surface), which represents irreversible reaction between the electrode surface and electrolyte. Linear-fit range of graphite and LiCo/O$_2$electrodes were respectively 370 and 150 mAh/g based on material weight. IIE of graphite and LiCo/O$_2$electrodes were respectively 93∼94 % and 94∼95 %, and IICs of graphite and LiCo/O$_2$electrodes were 15∼17 mAH/g and 0.3∼1.7 mAh/g, respectively. IIE of graphite/LiCo/O$_2$full cell for GX25 and DJG311 as graphite showed 89∼90 %, which IIE value was lower than IIE of half cell of the cathode and the anode. Parameters of IIE and IIC$_{s}$ can also be used to represent not only half cell but also full cell. The characteristics of the full cell can be simulated through the correlative interpretation of potential profile, IIE, and IIC$_{s}$ of half cells.cells.

• Journal of the Korean Chemical Society
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• v.21 no.6
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• pp.434-439
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• 1977

The electronic structures of 4-pyridone and lutidone are studied by the SCF MO-CI PPP method and by the configuration analysis method. The spectral data are consistent with the values calculated by the method. The polarization of $S_1({\pi},{\pi}^*)$ state is along the long molecular axis in both compounds. The lowest $({\pi},{\pi}^*)$1 state shows significant charge transfer (16∼18%) from ${\pi}$ bonding orbital of C=O moiety to ${\pi}^*$ antibonding orbital of divinyl amine moiety. The lowest triplet state shows much larger charge transfer (24∼29 %) but in opposite direction compared to that of $S_1({\pi},{\pi}^*)$ state.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.339-339
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• 2012

현재 MOS 소자에 사용되고 있는 $SiO_2$ 산화막은 그 두께가 얇아짐에 따라 Gate Leakage current와 여러 가지 신뢰성 문제가 대두되고 있고, 이를 극복하고자 High-k물질을 사용하여 기존에 발생했던 Gate Leakage current와 신뢰성 문제를 해결하고자 하고 있다. 본 실험에서는 High-k(hafnium) Gate Material에 온도 변화를 주었을 때 여러 가지 전기적인 특성 변화를 보는 방향으로 연구를 진행하였다. 기본적인 P-Type Si기판을 가지고, 그 위에 있는 자연적으로 형성된 산화막을 제거한 후 Hafnium Gate Oxide를 Atomic Layer Deposition (ALD)를 이용하여 증착하고, Aluminium을 전극으로 하는 MOS-Cap 구조를 제작한 후 FGA 공정을 진행하였다. 마지막으로 $300^{\circ}C$, $450^{\circ}C$로 30분정도씩 Annealing을 하여, 온도 조건이 다른 3가지 종류의 샘플을 준비하였다. 3가지 샘플에 대해서 각각 I-V (Gate Leakage Current), C-V (Mobile Charge), Interface State Density를 분석하였다. 그 결과 Annealing 온도가 올라가면 Leakage Current와 Dit(Interface State Density)는 감소하고, Mobile Charge가 증가하는 것을 확인할 수가 있었다. 본 연구는 향후 High-k 물질에 대한 공정 과정에서의 다양한 열처리에 따른 전기적 특성의 변화 대한 정보를 제시하여, 향후 공정 과정의 열처리에 대한 방향을 잡는데 도움이 될 것이라 판단된다.

• The Korean Journal of Ceramics
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• v.6 no.4
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• pp.339-342
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• 2000

In the present study, we attempted to apply DV-X$\alpha$ method to expressing the reactivity of materials. The expression of reactivity was discussed by comparison between ${\gamma}$-C$_2$G having hydraulic activity and ${\gamma}$-C$_2$S not having hydraulic activity at normal conditions. It was found that the model cluster used for calculation can finely reproduce the bulk and surface states using with and without point charge, respectively. The hydration state was also represented by placing OH￣ on the surface of the cluster. It was calculated that the bond strength of the first layer (as surface) was bigger than that of inner layers (as bulk) for ${\gamma}$-C$_2$S while that of the first layer for ${\gamma}$-C$_2$G was smaller than that of inner layers. Subsequently a model in which OH￣ is coordinated on Ca at the surface was also calculated. The bond strength with OH￣ was stronger than that without OH￣, while for ${\gamma}$-C$_2$G the bond strength with OH￣ was weaker than that without OH￣. From these results, it is concluded that the hydraulic activity depends on whether the bond strength for hydrated state becomes weaker than that unhydrated state or not.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.45-49
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• 2001

We have investigated physical and electrical properties of the Hf $O_2$/HfS $i_{x}$/ $O_{y}$ thin film for alternative gate dielectrics in the metal-oxide-semiconductor device. The oxidation of Hf deposited directly on the Si substrate results in the H $f_{x}$/ $O_{y}$ interfacial layer and the high-k Hf $O_2$film simultaneously. Interestingly, the post-oxidation N2 annealing of the H102/H1Si70y thin films reduces(increases) the thickness of an amorphous HfS $i_{x}$/ $O_{y}$ layer(Hf $O_2$ layer). This phenomenon causes the increase of the effective dielectric constant, while maintaining the excellent interfacial properties. The hysteresis window in C-V curves and the midgap interface state density( $D_{itm}$) of Hf $O_2$/HfS $i_{x}$/ $O_{y}$ thin films less than 10 mV and ~3$\times$10$^{11}$ c $m^{-2}$ -eV without post-metallization annealing, respectively. The leakage current was also low (1$\times$10-s A/c $m^2$ at $V_{g}$ = +2 V). It is believed that these excellent results were obtained due to existence of the amorphous HfS $i_{x}$/ $O_{y}$ buffer layer. We also investigated the charge trapping characteristics using Fowler-Nordheim electron injection: We found that the degradation of Hf $O_2$/HfS $i_{x}$/ $O_{y}$ gate oxides is more severe when electrons were injected from the gate electrode.e electrode.e.e electrode.e.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.137-138
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• 2017

본 논문에서는 각형 형태의 120Ah 고용량 배터리 ($LiNiMnCoO_2$; NMC)의 내부 파라미터 추출을 통해 배터리 관리 시스템(battery management system;BMS)에 중요한 팩터로 0.1C 및 0.25C 방전 조건에서 확장칼만필터(extended Kalman fileter;EKF) 기반으로 SOC(state-of-charge)를 추정하였다.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2003-2008
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• 2007

The aminolysis of diphenyl thiophosphinic chloride (2) with substituted anilines in acetonitrile at 55.0 oC is investigated kinetically. Kinetic results yield large Hammett ρX (ρnuc = ?3.97) and Bronsted βX (βnuc = 1.40) values. A concerted mechanism involving a partial frontside nucleophilic attack through a hydrogen-bonded, four-center type transition state is proposed on the basis of the primary normal kinetic isotope effects (kH/kD = 1.0-1.1) with deuterated aniline (XC6H4ND2) nucleophiles. The natural bond order charges on P and the degrees of distortion of 42 compounds: chlorophosphates [(R1O)(R2O)P(=O)Cl], chlorothiophosphates [(R1O)(R2O)P(=S)Cl], phosphonochloridates [(R1O)R2P(=O)Cl], phosphonochlorothioates [(R1O)R2P(=S)Cl], chlorophosphinates [R1R2P(=O)Cl], and chlorothiophosphinates [R1R2P(=S)Cl] are calculated at the B3LYP/ 6-311+G(d,p) level in the gas phase.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.9-17
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• 1996

Solid oxide electrolytes of 8mol% YSZ($Y_2O_3$ stabilized zirconia) were prepared at various sintering conditions and their ionic conductivities were measured. The highest ionic conductivity of $10^{-1}S.cm^{-1}$ was obtained when the sintering temperature was 1400oC and the sintering time was 10hr. Also the cathode material, $La_{1-x}Sr_xMnO_3$ was prepared by solid state reaction method and the overpotential, electrical conductivity, and charge transfer resistance between cathode material and YSZ electrolyte were studied. It was found that the optimum doping content of Sr for La was 50mo1%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.920-923
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• 2000

All solid-state thin film supercapacitor(TFSC) based on $RuO_2$ electrode was fabricated. Ruthenium oxide$(RuO_2)$ thin film was deposited on Pt/Ti/Si subsrate by d.c. magnetron sputtering. LiPON(lithium phosphorus oxynitride) thin film were deposited by r.f. reactive sputtering. X-ray diffraction patterns of $RuO_2$ and LiPON films revealed that crystal structures of both films were amorphous. To decrease resistivity of $RuO_2$ thin film, $RuO_2$ thin film was deposited with $H_2O$ vapor. In order to decide the maximum ionic conductivity, the LiPON films were prepared by various sputtering condition. The maximum ionic conductivity was $9.5\times{10}^7S/cm$. A charge-discharge measurements showed the capacity of $3\times{10-2}\;F/cm^2-\mu{m}$ for the as-fabricated TFSC. The discharging efficiency was decreased after 500 cycles by 40 %.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.117-127
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• 1994

In this paper, electrical and reliability properties of N$_2$O oxides, grown at the temperature of 95$0^{\circ}C$ and 100$0^{\circ}C$ to 74$\AA$, and 82$\AA$. respectively, using NS12TO gas in a conventional furnace, have been compared with those of pure oxide grown at the temperature of 850 to 84$\AA$ using O$_2$ gas. Initial IS1gT-VS1gT characteristics of N$_2$O oxides were similar to those of pure oxide, and reliability properties of N$_2$O oxides, such as charge trapping, interface state density and leakage current at low electric field under F-N stress, were improved much better than those of pure oxide. But, with increasing capacitor area. TDDB characteristics of N$_2$O oxides were more degraded than those of pure oxide and this degradation of TDDB characteristics was more severe in 100$0^{\circ}C$ N$_2$Ooxide than in 95$0^{\circ}C$ N$_2$O oxide. The improvement of reliability properties excluding TDDB in N$_2$Ooxides was attributed to the hardness of the interface improved by nitrogen pile-up at the interface of Si/SiO$_2$, but on the other hand, the degradation of TDDB characteristics in N$_2$O oxides was obsered due to the increase of local thinning spots caused by excessive nitrogen at interface during the growth of N$_2$O oxides.