• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.243.1-243.1
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• 2013

본 연구에서는 산소 분압과 열처리 온도에 따른 ITZO 박막 트랜지스터의 전기적 특성 향상을 목적으로 실험을 진행하였다. 1) ITZO 박막 증착 시 산소 분압 가변($O_2/(Ar+O_2)$ 30~40%), 열처리 온도 고정($350^{\circ}C$)과 2) ITZO 박막 증착 시 산소 분압 고정(30%), 열처리 온도($200{\sim}400^{\circ}C$)를 가변하여 실험을 진행하였다. 두 실험 모두 특성향상을 위해 산소 분위기에서 열처리를 진행하였다. 산소의 분압이 증가할수록 산소 빈자리를 채우면서 전자 농도가 감소하여 채널 전도 효과가 줄어들면서 Hump 현상이 발생하였고, 스윙이 증가, 문턱 전압이 음의 방향으로 이동하였다. 이에 $O_2/(Ar+O_2)$)의 30%에서 30%일때, 문턱전압은 1.98 V, 전계 효과 이동도는 28.97 $cm2/V{\cdot}s$, sub-threshold swing은 280 mv/dec, on-off 비율은 ~107로 가장 우수한 전기적 특성을 보였다. 또한 열처리 온도 가변 시 $400^{\circ}C$에서 전계 효과 이동도는 28.97 $cm^2/V{\cdot}s$로 $200^{\circ}C$의 전계 효과 이동도는 11.59 $cm^2/V{\cdot}s$에 비해 약 3배 증가하였고, 소자의 스위칭 척도인 sub-threshold swing은 약 180 mv/dec 감소하였다. 문턱 전압은 0.97V, on-off ratio는 약 107을 보였다. 동일한 산소 분압의 분위기에서 $400^{\circ}C$ 열처리 시 가장 우수한 전기적 특성을 보였고, 저온 공정으로 인한 플렉서블 디스플레이 투명 디스플레이 적용 가능성을 확인하였다.

• Composites Research
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• v.37 no.4
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• pp.286-290
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• 2024

The rapid increase in the demand for energy has put huge pressure on fossil fuels. The continuous overutilization of these existing non-renewable energy sources has been causing severe environmental concerns. In these regards, electrochemical water splitting has gained huge attention for producing green hydrogen, a superior energy source with high gravimetric energy density (120 MJ/kg), as compared with conventional options. Electrochemical water splitting is a viable option for generating green hydrogen. However, the various limitations of state-of the art Pt/C and RuO₂- based electrocatalysts has motivated the scientific community to develop novel cathode (hydrogen evolution reaction (HER)) and anode (oxygen evolution reaction (OER)) electrocatalysts. In our present study, we have achieved a new milestone by fabricating the NiMo-based transition metal LDHs coupled V₂C MXene support based heterocatalyst. The synergistic impact of NiMo LDHs (corrosion resistance, favorable intrinsic catalytic properties, etc.) and V₂C (high electrical conductivity, pseudocapacitive behavior, etc.) has resulted in the HER and OER at smaller overpotential of 135 and 370 mV at the current density of 10 and 30 mA cm-2 in an alkaline (1.0 M KOH) environment.

• Journal of Sensor Science and Technology
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• v.16 no.4
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• pp.259-262
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• 2007

This paper describes the electrical characteristics of polycrystalline (poly) 3C-SiC thin film diodes, in which poly 3C-SiC thin films on n-type and p-type Si wafers, respectively, were deposited by APCVD using HMDS, $H_{2}$, and Ar gas at $1150^{\circ}C$ for 3 hr. The schottky diode with Au/poly 3C-SiC/Si (n-type) structure was fabricated. Its threshold voltage ($V_{bi}$), breakdown voltage, thickness of depletion layer, and doping concentration ($N_{D}$) value were measured as 0.84 V, over 140 V, 61 nm, and $2.7{\times}10^{19}cm^{-3}$, respectively. Moreover, for the good ohmic contact, Al/poly 3C-SiC/Si (n-type) structure was annealed at 300, 400, and $500^{\circ}C$, respectively for 30 min under the vacuum condition of $5.0{\times}10^{-6}$ Torr. Finally, the p-n junction diodes fabricated on the poly 3C-Si/Si (p-type) were obtained like characteristics of single 3CSiC p-n junction diode. Therefore, poly 3C-SiC thin film diodes will be suitable for microsensors in conjunction with Si fabrication technology.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.103-115
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• 1981

The cathodic reactions of lead anodic films formed in phosphoric acid, oxalic acid and sodium hydroxide solutions and the reactivities of Di-iso-butylnitrosoamine (DBNA) in sea water at $15\sim30^{\circ}C$ were studied by means of constant current-potential method. Besides, various contants and thermodynamic quantities obtained in the experiment were also do-scribed to explain the reactivities of protons that entered in the anodic film by being transferred across the metal-oxide interface. The electrode reactions of lead anodic film formed in sodium hydroxide solution in 60mM DBNA+0.5M NaCl did not occur because of complete insulator formed on anodic film. The values of $(\partial\triangle E_{H^+}/\partial T)_{i=const}$, estimated with Bead anodic films formed in phosphoric acid in 60mM DBNA+0.5M NaCl and 60mM $DBNA+6\%_{\circ}$ sea water were $-0.006\;V/^{\circ}C\;and\;-0.005\;V/^{\circ}C$, thus being nearly coincided, but the values of $(\partial E_o/\partial T)_{i=o}$ were $0.002\;V/^{\circ}C\;and\;-0.002\;V/^{\circ}C$, being completely inversed.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.146-150
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• 2005

Two new barium vanadium borophosphate compounds, $(NH_4)_2(C_2H_{10}N_2)_6[Ba(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}8H_2O$, Ba- VBPO1 and $(NH_4)_8(C_3H_{12}N_2)_4[Ba(H_2O)_7][V_2P_2BO_{12}]_6{\cdot}17H_2O$, Ba-VBPO2 have been synthesized by interdiffusion methods in the presence of diprotonated ethylenediamine and 1,3-diaminopropane. Compound Ba-VBPO1 has an infinite chain anion (${[BaH_2O)_5]_2[V_2P_2BO_{12}]_6}$$^{14-}$, whereas Ba-VBPO2 has a discrete cluster anion {[$Ba(H_2O)_7][V_2P_2BO_{12}]_6$}$^{16-}$. Crystal Data: $(NH_4)_2(C_2H_{10}N_2)_6[Ba(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}8H_2O$, triclinic, space group P$\overline{1}$ (no. 2), a = 13.7252(7) $\AA$, b = 15.7548(8) $\AA$, c = 15.8609(8) $\AA$, α = 63.278(1)$^{\circ}$, $\beta$ = 75.707(1)$^{\circ}$, $\gamma$ = 65.881(1)$^{\circ}$, Z = 1; $(NH_4)_8(C_3H_{12}N_2)_4[Ba(H_2O)_7][V_2P_2BO_{12}]_6{\cdot}17H_2O$, monoclinic, space group C2/c (no. 15), a = 31.347(2) $\AA$, b = 17.1221(9) $\AA$, c = 22.3058(1) $\AA$, $\beta$ = 99.303(1)$^{\circ}$, Z = 4.

• Food Science and Preservation
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• v.21 no.4
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• pp.506-511
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• 2014

In Gyeongsangbuk-do seongju area, hundreds of tons of spoiled oriental melon are harvested annually. Therefore, ways to prevent such spoilage are needed. This study was conducted to investigate the quality characteristics of spoiled oriental melon juice after enzyme treatment for the production of oriental melon concentrate. The treatment of the oriental melon juice with three kinds of enzymes with variable concentrations showed the following results. PECE(1), which was compounded pectinase and cellulase at 0.01% (v/v), gave the melon a 0.16 brown color and 0.01 turbidity, and the highest L value of 97.00. The detected free sugar contents were fructose, glucose and sucrose, with the amount of sucrose the highest at roughly 4,000 mg%. The mixture of different enzyme treatments resulted in a 0.15 brown color and 0.01 turbidity at 60 minutes, and the L value was high at 97.25. The enzyme treatment temperatures of $50^{\circ}C$ and $60^{\circ}C$ yielded a low-level brown color and low turbidity, but the L values were high at $60^{\circ}C$ and $70^{\circ}C$. These results showed that 0.01% (v/v) mixing enzyme, i.e., pectinase and cellulose compounded at $60^{\circ}C$ for 60 min, must be used for the production of oriental melon concentrate.

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.715-722
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• 1994

Thermochromic $Vo_{2}$ thin films for "smart windows" were prepared by electron beam evaporationmethod on a glass substrate and spectral transmittances were examined by spectrophotometer. Substratetemperature of $300^{\circ}C$ and annealing temperature of $400^{\circ}C$ were found to be effective to give athermochromism on $Vo_{2}$ thin film due to the crystallization of the thin film. Furthermore, annealing of$Vo_{2}$ thin film affected the spectral transmittance and reduced the transmittance significantly at wavelengthbelow 500nm.$V_{0.95}W_{0.05}O_{2}$ thin film doped by 5 atomic percent of W showed semiconductor-metal transition around 0$0^{\circ}V_{0.995}W_{0.005}O_{2}$thin film which contains 0.5 atomic percent Sn showed therrnochrornisrn when it was depositedat substrate temperature of $300^{\circ}C$ and annealed at $450^{\circ}C$ for 5 hours in argon gas. The transitiontemperature of the $V_{0.995}W_{0.005}O_{2}$ thin film was found to be about $25^{\circ}C$ and showed some hysterisis. and showed some hysterisis.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.7-12
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• 2003

The $Bi_{3.3}La_{0.7}O_{12}$(BLT) capacitors with Metal-Ferroelectric-Insulator-Silicon structure were prepared on $SiO_2/Si$ substrates by using sol-gel method. The BLT thin films annealed at $650^{\circ}C$ and $700^{\circ}C$ showed randomly oriented perovskite crystalline structures. The full with at half maximum (FWHM) of the (117) main peak was decreased from $0.65^{\circ}$ to $0.53^{\circ}$ with increasing the annealing temperature from $650^{\circ}C$ to $700^{\circ}C$, indicating the improvement in the crystalline quality of the film. In addition, the grain size and $R_rms$ , values were increased with increasing the annealing temperatures, showing the rough film surface at higher annealing temperatures. From the capacitance-voltage (C-V) measurements, the memory window voltage of the BLT film annealed at $700^{\circ}C$ was found to be about 0.7 V at an applied voltage of 5 V. The leakage current density of the BLT film annealed at $700^{\circ}C$ was about $3.1{\times}10^{-8}A/cm^2$.

• Journal of Life Science
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• v.14 no.2
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• pp.362-367
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• 2004

For better understanding of the host infection mechanism of Vibrio, a Vibrio parahaemolyticus collagenase mutant was generated by insertional inactivation of a vppC gene encoding extracellular collagenase. A recombinant DNA containing vppC::nptII was cloned into a suicide plasmid pDMS197, resulted in pVCM03. The recombinant suicide plasmid pVCM03 contained in E. coli $\chi$7213 was transferred to a wild-type V. parahaemolyticus 04 through conjugation. The recombinant vppC::nptII DNA in pVCM03 was exchanged with wild-type allele by homologous recombination resulting vppC mutant, V. parahaemolyticus CM. The mutant was selected and screened on TCBS media containing 10% sucrose and kanamycin. The mutation by allele exchange was confirmed with the comparison of the size of DNAs amplified by PCR. V. parahaemolyticus CM showed at least 4-fold less collagen-degrading activity than those of wild-type, and the mutant exhibited less cytotoxicity than that of wild-type in MTT assay.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.71-71
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• 2000

본 연구에서는 차세대 마이크로파 유전체 소자로서의 응용을 목적으로 펄스 레이저 방식에 의하여 증착된 MgTiO3 박막의 전기적 특성을 종합적으로 연구 분석하였다. 이를 바탕으로 MgTiO3 박막의 유전손실 등과 같은 열화를 야기시키는 박막 내부 또는 박막과 기판간의 결함의 특성을 파악하여 열화 메카니즘을 분석하였다. MgTiO3는 마이크로파 영역에서의 우수한 유전특성과 같은 낮은 유전손실을 가지며, 온도 안정성 또한 우수하다. 현재까지 벌크 세라믹 MgTiO3 의 응용 광범위하게 연구되어 왔으나 박막의 제조공정 및 전기적 특성 분석은 미흡한 형편이다. 따라서 벌크 세라믹과는 특성이 상이한 박막의 전기적 특성분석 및 연구가 필요하다. 분석을 위한 소자의 기본 구조로서 Metal-Insulator-Semiconductor(MIS) 구조를 채택하였다. MgTiO3 박막을 증착하기 위한 기판으로는 n형 Si(100)기판과 p형 Si(100)기판을 사용하였고, Si 기판 위에 급속 열처리기 (RTP)를 이용하여 SiO2를 ~100 두께로 성장시킨 것과 성장시키지 않은 것으로 구분하여 제작하였다. MgTiO3 박막은 펄스 레이저 증착 방식(PLD)에 의하여 약 2500 두께로 증착되었으며, 200mTorr 압력의 산소 분위기 하에서 기판의 온도를 40$0^{\circ}C$~55$0^{\circ}C$까지 5$0^{\circ}C$간격으로 변화시키며 제작하였다. 상하부의 전극 금속으로는 Al을 이용하였으며, 열증발 증착기로 증착하였다. 증착된 MgTiO3 박막의 결정구조를 확인하기 위하여 XRD 분석을 수행하였으며, 박막의 전기적 특성을 분석하기 위해 Boonton7200 C-V 측정기와 HP4140P를 이용한 경우에는 C-V 곡선에 이력현상이 나타났으나, MgTiO3/SiO2를 이용한 경우에는 이력현상이 나타나지 않았고, 유전율은 감소하는 것으로 나타났다. I-V 측정 결과, 절연층으로 MgTiO3/SiO2를 이용한 경우에는 MgTiO3만을 절연층으로 사용한 경우에 비해 동일한 전계에서 낮은 누설전류 값을 가짐을 알 수 있었다. 또한 박막의 증착온도가 증가함에 따라서 C-V 곡선의 위치가 양의 방향으로 이동함을 확인하였다. 위의 현상은 기판의 종류에 관계없이 발생하는 것으로 보아 벌크 또는 계면에 존재하는 결함에 의한 것으로 추정된다. 현재 C-V 곡선의 이동 원인과 I-V 곡선의 누설전류 메카니즘을 분석 중에 있으며 그 결과를 학회에서 발표할 예정이다.