RF 마그네트론 스퍼터링을 이용한 p 타입 투명전도 산화물 SrCu₂O₂ 박막의 제조

석혜원,김세기,이현석,임태영,황종희,최덕균,Seok, Hye-Won,Kim, Sei-Ki,Lee, Hyun-Seok,Lim, Tae-Young,Hwang, Jong-Hee,Choi, Duck-Kyun 한국재료학회 2010 한국재료학회지 Vol.20 No.12

Most TCOs such as ITO, AZO(Al-doped ZnO), FTO(F-doped $SnO_2$) etc., which have been widely used in LCD, touch panel, solar cell, and organic LEDs etc. as transparent electrode material reveal n-type conductivity. But in order to realize transparent circuit, transparent p-n junction, and introduction of transparent p-type materials are prerequisite. Additional prerequisite condition is optical transparency in visible spectral region. Oxide based materials usually have a wide optical bandgap more than ~3.0 eV. In this study, single-phase transparent semiconductor of $SrCu_2O_2$, which shows p-type conductivity, have been synthesized by 2-step solid state reaction at $950^{\circ}C$ under $N_2$ atmosphere, and single-phase $SrCu_2O_2$ thin films of p-type TCOs have been deposited by RF magnetron sputtering on alkali-free glass substrate from single-phase target at $500^{\circ}C$, 1% $H_2$/(Ar + $H_2$) atmosphere. 3% $H_2$/(Ar + $H_2$) resulted in formation of second phases. Hall measurements confirmed the p-type nature of the fabricated $SrCu_2O_2$ thin films. The electrical conductivity, mobility of carrier and carrier density $5.27{\times}10^{-2}S/cm$, $2.2cm^2$/Vs, $1.53{\times}10^{17}/cm^3$ a room temperature, respectively. Transmittance and optical band-gap of the $SrCu_2O_2$ thin films revealed 62% at 550 nm and 3.28 eV. The electrical and optical properties of the obtained $SrCu_2O_2$ thin films deposited by RF magnetron sputtering were compared with those deposited by PLD and e-beam.

“IT는 방송용이 아니라고요?”

석혜원 (사)방송기자연합회 2014 방송기자 Vol.20 No.-

반응성 RF 마그네트론 스퍼터링에 의한 AlN 박막 제조 및 유압 감지 특성

석혜원,김세기,강양구,홍연우,이영진,주병권,Seok, Hye-Won,Kim, Sei-Ki,Kang, Yang-Koo,Hong, Yeon-Woo,Lee, Young-Jin,Ju, Byeong-Kwon 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.12

Aluminum nitride (AlN) thin film and TiN film as a buffer layer were deposited on INCONEL 600 substrate by reactive RF magnetron sputtering at room temperature(R.T.) under 25~75% $N_2/Ar$ atmosphere. The as-deposited AlN films at 25~50% $N_2/Ar$ showed a polycrystalline phase of hexagonal AlN, and an amorphous phase. The peak of AlN (002) plane, which was determinant on a performance of piezoelectric transducer, became strong with increasing the $N_2/Ar$ ratio. Any change in the preferential orientation of the as-deposited AlN films was not observed within our $N_2$ concentration range. The piezoelectric sensing properties of AlN module were performed using pressure-voltage measurement system. The output signal voltage of AlN module showed a linear behavior between 20~80 mV in 1~10 MPa range, and the pressure-sensing sensitivity was calculated as 3.6 mV/MPa.

Ni-Zn 레독스 플로우 전지에 있어서 양극의 전기화학적 특성에 미치는 쉬트 형상의 Ni 나노분말 첨가 효과

석혜원,김세기,강양구,홍연우,이영진,김범수,주병권,Seok, Hye-Won,Kim, Sei-Ki,Kang, Yang-Koo,Hong, Yeon-Woo,Lee, Young-Jin,Kim, Beom-Su,Ju, Byeong-Kwon 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.9

3 mol% Co-added $Ni(OH)_2$ fine powders, which showed ${\beta}$-phase, as positive electrode materials have been fabricated using $NiSO_4{\cdot}6H_2O$ aqueous solution by ultrasonic spray-chemical precipitation and subsequent hydrothermal method, and sheet-like Ni nanopowder was fabricated by mechano-chemical reduction method. The addition effects of the sheet-like Ni nanopowder on the electrochemical properties of the positive electrode in Ni-Zn Redox flow battery were investigated. Impedance spectroscopy revealed that the addition of the sheet-like Ni nanopowder resulted in decrease in the electrical resistivity; 10 wt.% addition reduced the electrical properties by a fifth. Cyclic voltammetry showed the addition of the sheet-like Ni nanopowder resulted in decrease in the potential difference of oxidation and reduction; this means the increase in the reversability for electrode reduction. Charge/discharge measurement confirmed that the addition of the sheet-like Ni nanopowder resulted in the increase in the discharge efficiency.

Pressure Sensing Properties of AlN Thin Films Sputtered at Room Temperature

석혜원 ( Hye Won Seok ),김세기 ( Sei Ki Kim ),강양구 ( Yang Koo Kang ),이영진 ( Youn Jin Lee ),홍연우 ( Yeon Woo Hong ),주병권 ( Byeong Kwon Ju ) 한국센서학회 2014 센서학회지 Vol.23 No.2

Aluminum nitride (AlN) thin films with a TiN buffer layer have been fabricated on SUS430 substrate by RF reactive magnetron sputtering at room temperature under 25~75% N2 /Ar. The characterization of film properties were performed using surface profiler, X-ray diffraction, X-ray photoelectron spectroscopy(XPS), and pressure-voltage measurement system. The deposition rates of AlN films were decreased with increasing the N2 concentration owing to lower mass of nitrogen ions than Ar. The as-deposited AlN films showed crystalline phase, and with increasing the N2 concentration, the peak of AlN(100) plane and the crystallinity became weak. Any change in the preferential orientation of the as-deposited AlN films was not observed within our N2 concentration range. But in the case of 50% N2/Ar condition, the peak of (002) plane, which is determinant in pressure sensing properties, appeared. XPS depth profiling of AlN/TiN/SUS430 revealed Al/N ratio was close to stoichiometric value (45:47) when deposited under 50% N2/Ar atmosphere at room temperature. The output signal voltage of AlN sensor showed a linear behavior between 26~85 mV, and the pressure-sensing sensitivity was calculated as 7 mV/MPa.

상온에서 성막한 고감도의 Al1-xScxN 박막의 압력 감지 특성

석혜원 ( Hye Won Seok ),김세기 ( Sei Ki Kim ),강양구 ( Yang Koo Kang ),이영진 ( Young Jin Lee ),홍연우 ( Yeon Woo Hong ),주병권 ( Byeong Kwon Ju ) 한국센서학회 2014 센서학회지 Vol.23 No.6

Aluminum-scandium nitride (Al1-xScxN) thin films with a TiN buffer layer have been fabricated on SUS430 substrate by RF reactive magnetron sputtering at room temperature under 50% N2/Ar. The effect of Sc-doping on the structure and piezoelectric properties of AlN films has been investigated using SEM, XRD, surface profiler and pressure-voltage measurements. The as-deposited AlN films showed polycrystalline phase, and the Sc-doped AlN film, the peak of AlN (002) plane and the crystallinity became very strong. With Sc-doping, the crystal size of AlN film was grown from ~20 nm to ~100 nm. The output signal voltage of AlN sensor showed a linear behavior between 15~65 mV, and output signal voltage of Sc-doped AlN sensor was increased over 7 times. The pressure-sensing sensitivity of AlN film was calculated about 10.6mV/MPa, and Al0.88Sc0.12N film was calculated about 76 mV/MPa.

외측 인대 손상 환자들을 위한 발목 재활 보조 로봇

이소화,석혜원,김예지,신유진,최현진 제어로봇시스템학회 2023 제어로봇시스템학회 국내학술대회 논문집 Vol.2023 No.6

정서적 고갈과 수면의 질의 관계에 대한 심리적 분리의 매개효과

김보람,석혜원,장재윤 한국심리학회 2021 한국심리학회지 일반 Vol.40 No.2

This study investigated the indirect effect of psychological detachment on the relationship between emotional exhaustion and sleep quality. A daily survey (twice a day from Monday to Friday) was conducted to examine whether emotional exhaustion may predict sleep quality via psychological detachment at the within-person level. Results revealed that: 1) daily emotional exhaustion leaving the office was negatively related to the psychological detachment after work; 2) daily psychological detachment after work was positively related to the quality of sleep at night; 3) daily psychological detachment mediated the relationship between emotional exhaustion and sleep quality. These findings can enhance understanding of the process by which psychological mechanism contributes to sleep quality on a daily basis. This study also demonstrates that mentally “switch off” would supplement resources depleted at work and lessen the level of mental activation and arousal to get better sleep. 본 연구는 정서적 고갈과 수면의 질 간의 관계에서 심리적 분리의 간접효과를 검증하였다. 직무 요구상 여러 학생들을 대상으로 자신의 정서를 조절해야 하는 기혼 여교사 78명을 대상으로 일일 조사(월요일부터 금요일까지 하루 2회조사) 자료를 통해 개인 내 수준에서 정서적 고갈이 심리적 분리를 통해 수면의 질을 예측할 수 있는지 검증하였다. 본 연구의 결과는 다음과 같다. 첫째, 매일 퇴근 무렵 경험하는 정서적 고갈의 정도가 퇴근 후 심리적 분리와 부적인 관련성을 보였다. 둘째, 매일 퇴근 후 심리적 분리의 정도는 그날 밤 수면의 질과 정적인 관련성을 보였다. 셋째, 정서적 고갈을 많이 경험할수록 일로부터 심리적으로 분리하지 못하며, 이는 낮은 질의 수면으로 이어지는 심리적 분리의 매개효과가 나타났다. 마지막으로 본 연구의 시사점, 제한점 및 추후 연구방향을 논의하였다.

1인 가구와 다인 가구의 사회경제적 수준, 건강 행태와대사증후군에서의 차이: 성별과 세대에 따른 분석

조영경,심경원,석혜원,이홍수,이상화,변아리,이한나 대한가정의학회 2019 Korean Journal of Family Practice Vol.9 No.4

Background: The rising popularity of one-person households makes the health hazards they are prone to, highly relevant in epidemiological studies. This study aimed at comparing health-related characteristics like the socioeconomic status, health behavior, and metabolic syndrome of one-person households, to multi-person households in Korea. Methods: The participants required for this study included 9,423 Koreans aged 19 and above, who took the Sixth Korean National Health and Nutrition Examination Survey. The household types were classified into “one-person” and “multi-person.” The differences between the two, based on their annual socioeconomic status, health behavior, anthropometric variables, and blood test results were analyzed. Results: The percentage of men and women in one-person households was 7.2% and 10.5%, respectively. Such households had a lower annual income and education than multi-person households. The odds ratios (OR) for alcohol consumption (OR, 1.69; 95% confidence interval [CI], 1.16–2.46) and smoking (OR, 3.24; 95% CI, 1.77–5.95) were significantly higher for one-person households of women, aged 60 and above, compared to multi-person households. The OR for metabolic syndrome was considerably higher in one-person households of middle-aged people in contrast to multi-person households for both men (OR, 1.84; 95% CI, 1.14–2.95) and women (OR, 1.90; 95% CI, 1.21–2.99). Conclusion: The socioeconomic status was lower, and the health behaviors were worse in one-person households as compared to multi-person households. Considering the growing popularity of one-person households, it is suggested that medical plans be customized to suit the characteristics of the specific group. 연구배경: 우리나라는 최근에 핵가족을 넘어서 홀로 가구를 구성하여 거주하는 1인 가구가 급증하고 있다. 하지만 1인 가구에 대한연구는 많이 이루어지지 않았고, 1인 가구에 대한 대부분의 연구는노인 1인 가구에 집중되어 있다. 따라서 본 연구는 연령과 성별에 따라 1인 가구의 사회경제적 수준, 건강 행태와 대사증후군을 다인 가구와 비교해 보고자 수행되었다. 방법: 국민건강영양조사 6기 참여자 중 19세 이상의 성인 9,423명을대상으로 하였다. 가구의 형태는 1인 가구와 비1인 가구의 2가지 유형으로 구별하였다. 연구 대상자들의 소득 수준, 교육 수준, 흡연, 음주, 운동, 신체계측, 혈액검사 자료를 이용하여 성별과 연령에 따른 1인 가구와 다인 가구의 차이를 분석하였다. 결과: 연구 대상 중 1인 가구의 비율은 남성에서 7.2%였고, 여성에서는 10.5%였다. 1인 가구의 소득 수준과 교육 수준이 비 1인 가구와 비교하였을 때 더 낮게 나타났다. 1인 가구 노년 여성에서의 음주에 대한 교차비는 1.69 (95% confidence interval [CI], 1.16−2.46)로 유의하게높았고 흡연은 3.24 (95% CI, 1.77−5.95)로 유의하게 높았다. 대사증후군의 교차비는 1인 가구 중장년층 남성에서 1.84 (95% CI, 1.14−2.95),중장년층의 여성에서 1.90 (95% CI, 1.21−2.99)로 유의하게 높았다. 결론: 1인 가구는 비 1인 가구와 비교하였을 때 사회 경제적 수준이낮고 건강 행태 및 대사증후군에서 보다 취약한 것으로 나타났다. 1인 가구가 증가하는 추세를 미루어 볼 때 1인 가구에 대한 사회 전반적인 의료적 지원이 고려되어야 하며, 연령과 성별에 따라 집단별 특성에 맞춘 계획이 필요하다.

RF Magnetron Sputtering을 이용하여 제작한 불용성 촉매전극의 해수전기분해 특성

이현석,김세기,석혜원,김진호,최헌진,정하익,Lee, Hyun-Seok,Kim, Sei-Ki,Seok, Hye-Won,Kim, Jin-Ho,Choi, Hun-Jin,Jung, Ha-Ik 한국재료학회 2012 한국재료학회지 Vol.22 No.2

Insoluble catalytic electrodes were fabricated by RF magnetron sputtering of Pt on Ti substrates and the performance of seawater electrolysis was compared in these electrodes to that is DSA electrodes. The Pt-sputtered insoluble catalytic electrodes were nearly 150 nm-thick with a roughness of $0.18{\mu}m$, which is 1/660 and 1/12 of these values for the DSA (dimensionally stable anodes) electrodes. The seawater electrolysis performance levels were determined through measurements of the NaOCl concentration, which was the main reaction product after electrolysis using artificial seawater. The NaOCl concentration after 2 h of electrolysis with artificial seawater, which has 3.5% NaCl normally, at current densities of 50, 80 and 140 mA/$cm^2$ were 0.76%, 1.06%, and 2.03%, respectively. A higher current density applied through the electrodes led to higher electrolysis efficiency. The efficiency reached nearly 58% in the Pt-sputtered samples after 2 h of electrolysis. The reaction efficiency of DSA showed higher values than that of the Pt-sputtered insoluble catalytic electrodes. One plausible reason for this is the higher specific surface area of the DSA electrodes; the surface cracks of the DSAs resulted in a higher specific surface area and higher reaction sites. Upon the electrolysis process, some Mg- and Ca-hydroxides, which were minor components in the artificial seawater, were deposited onto the surface of the electrodes, resulting in an increase in the electrical resistances of the electrodes. However, the extent of the increase ranged from 4% to 7% within an electrolysis time of 720 h.