Hot - wall epitaxy에 의한 Zn - chalcogenide 에피층의 성장 및 구조적 특성

유영문(Young-Moon Yu),남성운(Sungun Nam),이종광(Jongkwang Rhee),오병성(Byungsung O),이기선(Ki-Seon Lee),최용대(Yong Dae Choi),이종원(J. W. Lee) 한국진공학회(ASCT) 1999 Applied Science and Convergence Technology Vol.8 No.4(1)

열벽적층성장법으로 ZnS 및 ZnTe 단결정 박막을 GaAs(100)와 GaP(100) 기판에 성장하였다. 성장한 박막의 방향성 및 결정성을 알아보기 위하여 X-ray 회절과 이중 결정 요동 곡선(DCRC)을 측정하였다. 성장한 박막은 (100) 방향의 zinc-blende 구조를 갖는 단결정임을 알았다. ZnTe 단결정 박막은 93 arcsec의 아주 좋은 DCRC 반치폭 값을 얻었고 ZnS 단결정 박막도 매우 양호한 결과를 얻었다. 두께에 따른 DCRC 반치폭의 변화로부터 단결정 박막 내에 남아있는 스트레인은 격자부정합에 의한 영향뿐만 아니라 열팽창계수 차이에 의한 것도 있음을 알았다. ZnS and ZnTe epilayers were grown on GaAs(100) and GaP(100) substrates by hot-wall epitaxy. X-ray diffraction revealed that the epilayers have zinc-blende structure and were grown in (100) direction. The small values of the full width at half maximum (FWHM) of double crystal rocking curve (DCRC) showed high quality of the epilayers. From the thickness dependence of the FWHM of DCRC, the strain remaining in films is found to be due to the thermal expansion difference as well as due to the lattice mismatch.

표준기록관리시스템(RMS)의 기능 현황 및 발전방향 10년의 운영 경험과 기능 개선 사항을 중심으로

유영문,Yu, Young Moon 한국기록학회 2018 기록학연구 Vol.0 No.57

전자기록물이 중앙행정기관에서 생산된 후 국가기록원까지 이관되고 있다. 전자기록물에 하자 또는 오류가 없는 경우에 범정부 전자기록관리 체계가 정상적으로 작동되고 있다는 방증이다. 이 과정에서 다양한 문제 점이 도출되었고, 현재도 해결해야 할 문제점이 남아 있다. 그 중심에는 표준기록관리시스템이 있고, 지속적인 기능 개선이 이루어져 왔다. 본고에 서는 표준기록관리시스템의 기록관리 기능에 대한 기능별 개선 내용을 소 개하고 있다. 이 중 중요 사안은 기능 개선된 배경이나 사유 및 개선 사항 을 사례를 들어 설명하였다. 그리고 표준기록관리시스템의 발전방향을 기 록관리 종사자의 인식전환, 사용자와 개발자 간의 협력 강화, 메타데이터 품질 개선, 유관시스템 연계, 기록관리 자동화 및 IT 환경 변화 등의 측면 에서 살펴보았다. Electronic records produced by central administrative agencies are transferred to the National Archives of Korea. In the absence of defects or errors in electronic records, it is a proof that the government’s electronic records management system is operating normally. Various problems have been found in this process, and there still remain problems to be solved. At the heart of it is a standard records management system, which has been continuously improved. In this paper, I introduce the functional improvement of the record management functions of the standard records management system. Among them, the important matters describe the background and reason for the improvement. In addition, the direction of development of the standard records management system was examined in terms of recognition conversion of recordkeepers, strengthen collaboration between recordkeepers and developers, improving records management metadata quality, linking related systems, automating records management, and IT environment change.

수열법에 의한 청색수정의 성장

이영국,유영문,정석종,고재천,박로학,Lee Young Kuk,Yu Young Moon,Jung Suk Jong,Koh Jae Cheon,Bak Ro Bak 한국결정학회 1997 韓國結晶學會誌 Vol.8 No.1

고온고압용 autoclave에서 $Na_2CO_3$를 광화제로 하여 청색수정 단결정을 수열성장하고, 성장온도와 코발트 함입량과의 관계를 고찰하였다. $5wt.\%$의 $Na_2CO_3$ 수열용액, $343^{\circ}C$의 성장온도, $22^{\circ}C$의 온도구배, 950기압의 조건에서 $100{\times}50{\times}35mm^3$ 크기의 청색수정을 성장하였으며, 성장속도는 0.55 mm/day였다. 가시영역에서의 흡수 스펙트럼을 측정한 결과 545, 570 및 643 nm 근처에서 흡수피크가 관찰되었다. 청색의 농도는 원료내 코발트의 농도와는 무관하며 성장온도와 밀접한 관계가 있음을 확인하였다. Single crystals of Co-doped quartz (blue quartz) were grown hydrothermally from the $Na_2CO_3$ solution. The size of as-grown crystal was $100{\times}50{\times}35mm^3$ and the growth rate was 0.55 mm/day under the growth condition of $5wt.\%\;Na_2CO_3$ mineralizer, growth temperature of $343^{\circ}C$ and temperature gradient of $22^{\circ}C$. Visible spectrum showed a typical absorption feature of the synthetic blue quartz near 545, 570 and 643 nm. The concentration of color of the as-grown blue quartz related not to the concentration of cobalt in raw material but to the growth temperature.

Er과 Yb이 동시 도핑된 YCa₄B₃O₁₀의 광 특성

장원권,유영문,Jang, Won-Kweon,Yu, Young-Moon 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.12

Optical characteristics of $YCOB(YCa_4B_3O_{10})$, known as a crystal of self frequency doubling, was investigated when Yb and Er ions were co-doped 20 % and 2 %, respectively. The absorption cross section of Er,Yb:YCOB crystal at $1.0\;{\mu}m$ was larger than that of Yb:YCOB, which means that the former was profitable for more energy absorption than the latter. The fluorescent lifetime at $1.5\;{\mu}m$ was measured to be 1.27 ms at room temperature, and lengthened to 1.54 ms and 1.62 ms at low temperatures of 77 K and 6 K, respectively. The line widths of fluorescent spectrum at $1.5\;{\mu}m$ were getting narrower as lowering temperature. However, we didn't observe a temperature dependent peak wavelength shift.

Yb:YCa₄O(BO₃)₃ 단결정 성장과 분광 및 열적 특성 연구

김충렬,이현준,유영문,Kim, Choong-Ryeul,Lee, Hyeon-Jun,Yu, Young-Moon 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.8

융액인상법으로 질소분위기 하에서 $Yb^{3+}$ 이온이 20at% 고용된 $Yb:YCa_4O(BO_3)_3$ (Yb:YCOB) 단결정을 이리듐 도가니를 사용하여 성장시켰다. 양질의 단결정을 성장시키기 위한 인상속도와 회전속도는 각각 1.5∼2 mm/h와 10∼20 rpm이었다. 분광물성 측정 결과, 흡수단이 236 nm에 있었으며, 전형적인 $Yb^{3+}$ 이온의 흡수 스펙트럼이 관찰되었다. Yb:YCOB의 열팽창계수는 320∼650 K의 측정범위에서 결정학적 축 a, b 그리고 c에 대해 12.1×$10^{-6}$ /K, 5.9${\times}10^{-6}$/K, 12.9${\times}10^{-6}$이었다. 비열은 330 K에서 0.162 $cal/g{\cdot}K$이었다. Yb:$YCa_4O(BO_3)_3$ (Yb:YCOB) single crystal, in which the concentration of $Yb^{3+}$ ion 20 at%, was grown by the Czocharalski method using an iridium crucible under N2 atmosphere. The optimum growth parameters to get a high quality of single crystals were found to be 1.5∼2 mm/h of pulling rate and 10∼20 rpm of rotation rate. According to the results of spectroscopic properties, absorption edge of Yb:YCOB was 236 nm. Two strong absorption line due to $Yb^{3+}$ ions were observed at 900 and 975 nm. Thermal expansion coefficients of Yb:YCOB crystal along a, b and c crystallographic axes from 320 to 650 K were 12.1${\times}10^{-6}$/K, 5.9${\times}10^{-6}$/K, 12.9${\times}10^{-6}$/K, respectively. Specific heat was 0.162 $cal/g{\cdot}K$ at 330 K.

다이캐스팅용 알루미늄의 성분 변화에 따른 LED 방열 특성 연구

여정규,허인성,유영문,이세일,최희락,Yeo, Jung-Kyu,Her, In-Sung,Yu, Young-Moon,Lee, Se-Il,Choi, Hee-Lack 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.8

Because of the development of LED technology, products due to high output and compact, the material with high thermal conductivity has been developed. Now that heat radiating part of the LED lamp is currently used for die casting of aluminum. The development of aluminum with excellent thermal conductivity is required. In this study, we measured the thermal properties and compared them while we produced the alloy by changing the component of die casting aluminum. From this study, the thermal conductivity and thermal resistance of the developed alloy were superior to die casting aluminum.

개인감성 충족을 위한 선박 다인실 침상 조명연구 및 개발

허제문(Je Moon Hoe),이성재(Sung Je Lee),유영문(Young Moon Yu) 한국조명·전기설비학회 2017 한국조명·전기설비학회 학술대회논문집 Vol.2017 No.11

색온도 가변 LED 조명 최적화 설계 및 제작

강다일,김근율,유영문,최희락,Kang, Da-Il,Kim, Kun-Yul,Yu, Young-Moon,Choi, Hee-Lack 한국광학회 2014 한국광학회지 Vol.25 No.2

본 논문에서는 현재 양산되고 있는 Red(621 nm), Green(530 nm), Blue(453 nm), Amber(590 nm) 등 4파장의 LED 조합을 이용하여 색온도가 가변되는 동안에도 평균연색지수 및 특별연색지수 R9 값이 높게 유지될 수 있도록 조명의 스펙트럼을 최적화하였다. 최적화 시 설계의 정확도를 높이기 위하여 실제 측정한 LED 스펙트럼을 사용하였고 광선과 기구물 사이의 상호 작용을 고려한 광선 추적 기법을 활용하여 수행하였다 또한 최적화 결과를 검증하기 위하여 색온도 가변 조명 장치를 직접 제작하였으며 광 특성을 평가한 결과 색온도가 3000 K에서 6000 K까지 변하는 동안 CRI 및 R9 값이 각각 87~90, 34~93을 나타내었다. In this paper the spectra of correlated color temperature (CCT) tunable white light-emitting diode (LED) luminaires, consisting of commercial red, green, blue, and amber LED chips, were optimized to increase color rendering index (CRI), and a special CRI of R9 for deep red color was obtained. To improve the design's accuracy, measured LED spectra were used instead of mathematically modeled ones. Real CCT tunable LED luminaires with CRIs of 87-90 and R9s of 34-93 were fabricated and demonstrated at CCTs of 3000-6000 K.

LED터널등 모듈의 폐열활용을 위한 열전소자의 발전 성능 분석

정지영(Ji-Young Jeong),허인성(In-Sung Her),이세일(Se-Il Lee),김명호(Myeong-Ho Kim),유영문(Young Moon Yu) 한국조명·전기설비학회 2015 조명·전기설비학회논문지 Vol.29 No.8

In this paper, we propose the LED(Light-Emitting-Diode) emergency lighting in a tunnel by using the thermoelectric devices. To achieve high generated power, thermoelectric device should be have high Seebeck coefficient and small contact area. Also, we reveal that a moderate heatsink required for high generated power. From the waste heat of LED tunnel lighting module (25W), the generated power was 0.062W by thermoelectric device, and it could illuminate for 1hour after charge the battery of emergency lighting during about 101hours.

열전소자 적용을 위한 LED 엔진 모듈 설계와 특성 분석

정지영(Ji-Young Jeong),강민규(Min-Gyu Kang),김승재(Seung-Jae Kim),유영문(Young Moon Yu) 한국조명·전기설비학회 2016 조명·전기설비학회논문지 Vol.30 No.7

Variation of thermal resistivity depending on temperature difference and measurement of thermal resistivity of thermoelectric device in LED lighting engine module were studied. Power generated from waste heat and photometric characteristics of LED engine module were measured. From the measured and analysed data, the followings were concluded. Control of temperature difference at the low temperature was advantageous for LED module compared to temperature difference control at high temperature. The sum of the measured thermal resistance of LED module and thermoelectric device was 2.654K/W and the measured total thermal resistance was 2.41K/W. In a thermal simulation, minimum LED p-n junction temperature was 69.3℃ when 23 pieces of pins with 1mm thickness were used. When 700mA was applied to the LED engine module, 0.086W of maximum power was obtained with 0.15A of load. Light efficiency of LED module with thermoelectric device was 126.9lm/W and 3.7lm/W of efficiency decrement.