분무열분해법으로 성장된 In2O3:Cd 박막의 구조와 광학적 전기적 특성

서동주 한국물리학회 2009 새물리 Vol.59 No.2

In2O3:Cd films were deposited on the glass substrates by spray pyrolysis. The crystal structure of In2O3:Cd films prepared with Cd concentration up to 10 at% were identified as Cd-doped In2O3 (In2O3:Cd) with preferred orientation (222) of a cubic structure. There are no new compounds in the In2O3:Cd. The optical transmission of the samples deposited with various Cd concentration were about 80∼95 % in the wavelength range from 400 to 1200 nm. The optical energy gap of the In2O3:Cd films deposited with a Cd concentration of 7 at% was 3.611 eV. The optical energy gaps of the In2O3:Cd films decreased with increasing Cd concentration up to 3 at.% and there after it slightly increased for the higher Cd concentration. Electric resistivity, carrier concentration, Hall coefficient and mobility of the In2O3:Cd films deposited with a Cd concentration of 7 at% were 1.45×10-3Ω·cm, 6.80×1019cm-3, 91.72m2/C. 5.46×103cm2/V·s respectively. In2O3:Cd 박막을 분무열분해법으로 유리기판 위에 성장시켰다. Cd를 0∼10 at%까지 첨가하여 성장시킨 In2O3:Cd 박막의 결정구조는 입방구조이며, (222)면이 뚜렷하게 성장되었고 Cd이 불순물로 첨가된 In2O3 (In2O3:Cd) 박막으로 확인되었다. In2O3:Cd 박막의 광학적 투과율은 400∼ 1200 nm 영역에서 75∼95 %이었다. Cd을 7 at% 첨가하여 성장시킨 In2O3:Cd 박막의 광학적 에너지 띠간격은 3.611 eV이었고, In2O3:Cd 박막의 광학적 에너지 띠간격은 Cd의 농도가 3 at%까지는 감소하는 반면 그 이상의 농도에서는 거의 일정하였다. Cd를 7 at% 첨가하여 성장시킨 시료의 경우 p-형 전도성이 다른 시료보다 좋았는데, 이 시료의 비저항, 운반자농도, 홀계수, 이동도는 각각 1.45×10-3Ω·cm, 6.80×1019cm-3, 91.72m2/C. 5.46×103cm2/V·s 이었다.

진공증착법에 의해 제작된 Cd₂GeSe₄와 Cd₂GeSe₄:Co<SUP>2+</SUP> 박막의 물리적 특성

이정주(Jeoung Ju Lee),성병훈(Byeong Hoon Sung),이종덕(Jong Duk Lee),박창영(Chang Young Park),김건호(Kun Ho Kim) 한국진공학회(ASCT) 2009 Applied Science and Convergence Technology Vol.18 No.6

진공증착법으로 Cd₂GeSe₄와 Cd₂GeSe₄:Co<SUP>2+</SUP> 박막을 ITO(indium tin oxide) 유리 기판 위에 제작하였다. 결정화는 증착된 박막들을 질소분위기의 전기로에서 열처리함으로서 이룰 수 있었다. X-선 회절 분석에 의하여 증착된 Cd₂GeSe₄와 Cd₂GeSe₄:Co<SUP>2+</SUP> 박막의 격자상수는 a = 7.405 Å, c = 36.240 Å와 a = 7.43 Å, c = 36.81 Å로서 능면체(rhombohedral) 구조이었고, 열처리 온도를 증가함에 따라 (113)방향으로 선택적으로 성장됨을 알 수 있었다. 열처리 온도를 증가시킴에 따라 입계 크기가 점차 커지고 판상구조로 결정화 되었다. 실온에서 측정한 광학적인 에너지 띠 간격은 열처리 온도의 증가에 따라 Cd₂GeSe₄ 박막의 경우 1.70 eV ~ 1.74 eV로 증가하였고, Cd₂GeSe₄:Co<SUP>2+</SUP> 박막의 경우 1.79 eV ~ 1.74 eV로 감소하였다. Cd₂GeSe₄와 Cd₂GeSe₄:Co<SUP>2+</SUP> 박막 내의 전하운반자들의 동역학적 거동을 광유기 방전 특성(PIDC : photoinduced discharge characteristics) 방법으로 조사하였다. Cd₂GeSe₄ and Cd₂GeSe₄:Co<SUP>2+</SUP> films were prepared on indium-tin-oxide(ITO)-coated glass substrates by using thermal evaporation. The crystallization was achieved by annealing the as-deposited films in flowing nitrogen. X-ray diffraction spectra showed that the Cd₂GeSe₄ and the Cd₂GeSe₄:Co<SUP>2+</SUP> films were preferentially grown along the (113) orientation. The crystal structure was rhomohedral(hexagonal) with lattice constants of a=7.405 Å and c=36.240 Å for Cd2GeSe4 and a=7.43 Å and c=36.81 Å for Cd₂GeSe₄:Co<SUP>2+</SUP> films. From the scanning electron microscope images, the Cd₂GeSe₄ and Cd₂GeSe₄:Co<SUP>2+</SUP> films were plated, and the grain size increased with increasing annealing temperature. The optical energy band gap, measured at room temperature, of the as-deposited Cd₂GeSe₄ films was 1.70 eV and increased to about 1.74 eV and of the as-deposited Cd₂GeSe₄:Co<SUP>2+</SUP> films was 1.79 eV and decreased to about 1.74 eV upon annealing in flowing nitrogen at temperatures from 200℃ to 500℃. The dynamical behavior of the charge carriers in the Cd₂GeSe₄ and Cd₂GeSe₄:Co<SUP>2+</SUP> films were investigated by using the photoinduced discharge characteristics technique.

Structural and Optical Properties of Cd2GeSe4 and Cd2GeSe4:Co2+ Films Prepared on Indium-tin-oxide Substrates

이정주,D. H. Han,이종덕,박창영,김건호 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.4

Cd2GeSe4 and Cd2GeSe4:Co2+ films were prepared on indium-tin-oxide (ITO)- coated glass substrates. X-ray diffraction spectra showed that the Cd2GeSe4 and the Cd2GeSe4:Co2+ films were preferentially grown with the (113) orientation. The crystal structure was rhombohedral (hexagonal)with lattice constants a = 7.405 °A and c = 36.24 °A for Cd2GeSe4 films and a = 7.43 °A and c = 36.81 °A for Cd2GeSe4:Co2+ films. From X-ray photoelectron spectroscopy, the binding energies of the Cd-3d, the Ge-3d, and the Se-3d core levels due to the formations of Cd2GeSe4and Cd2GeSe4:Co2+ were found to be 404.5 eV and 411.3 eV, 30.4 eV and 31.3 eV, and 54.7 eV and 58.9 eV, respectively. The optical energy band gaps, measured at room temperature, of the as-deposited Cd2GeSe4 and Cd2GeSe4:Co2+ films were 1.97 eV and 1.72 eV and those of the 400C-annealed films were 1.85 eV and 1.7 eV, respectively. The dynamical behaviors of the charge carriers in the Cd2GeSe4 and Cd2GeSe4:Co2+ films were investigated by using the photoinduced discharge characteristics (PIDC) technique.

레이더경보수신기용 CD대역 진폭비교 방향탐지 정확도 측정 시스템 개발

현예지,최남우,최혁재,조원택,김성훈 대한전자공학회 2022 전자공학회논문지 Vol.59 No.11

Radar Warning Receiver(RWR) is Electronic Warfare Support equipment, which detects and measures threat radar signal in high speed then provides real time warning. This paper describes the development of an amplitude comparison direction finding accuracy measuring system for CD band RWR, which is intended to be loaded on aircraft for the first time in Korea. The developed RWR equipment receives CD band signal from Blade Antenna, executes signal processing in RF and Digital module, and derives angle of arrival(AOA) using the amplitude comparison direction finding logic. Since CD band blade antenna has an unbalanced beam pattern, unlike EJ band or spiral antenna, this paper measures direction finding accuracy by adding a beam calibration algorithm. As a result of conducting a radiation test on the CD band in the anechoic chamber to verify the direction finding accuracy, the performance is confirmed that the average CD band direction finding accuracy is measured by 6.73% higher than the target performance of OO degree RMS in 360 degree azimuth and 45 degree elevation range.

Energy band alignment at the ALD Zn<SUB>1-x</SUB>Mg<SUB>x</SUB>O/Cu(In,Ga)Se₂ interface for Cd-free CIGS solar cells

Chang-Soo Lee(이창수),Liudmila Larina(라리나),Young-Min Shin(신영민),Byung Tae Ahn(안병태) 한국신재생에너지학회 2012 한국신재생에너지학회 학술대회논문집 Vol.2012 No.06

Old Problems and New Challenges Recent Advances Of Endoscopy In Inflammatory Bowel Diseases

( Won Ho Kim ),( Jae Hee Cheon ) 대한소화기학회 2007 SIDDS Vol.9 No.-

Endoscopy plays a key role for the diagnosis and treatment in inflammatory bowel disease (IBD). The single most valuable tool for distinguishing the different forms of IBD is a complete ileocolonoscopy with mucosal biopsy. Endoscopic localization of disease not only aids in determining prognosis and appropriateness of medical therapies but also help decision making in those undergoing surgical therapy. In addition, obstructive symptoms caused by benign fibrotic strictures can be treated adequately by endoscopic balloon dilation. Epidemiological studies have demonstrated an increased risk of colorectal cancer in patients with both UC and colonic CD. In terms of cancer surveillance, colonoscopy is considered currently to be the gold standard. Published guidelines recommend that 2∼4 biopsies should be taken every 10 cm in the colorectum, rendering 20∼50 biopsies per examination. However, standard colonoscopy is far from perfect and may miss significant numbers of small lesions. Furthermore, it is very time-consuming and laborious. To overcome those problems, there have been many efforts to reduce biopsies taken and time of examinations through various novel techniques, including chromoendoscopy with or without magnification, fluorescence endoscopy, narrow band inaging (NBI), optical coherence tomography (OCT) and confocal laser endomicroscopy. Until recently the only way to evaluate the small bowel mucosa in a patient with CD was by barium small bowel radiographs and intubation of the distal terminal ileum. Both WCE (wireless capsule endoscopy) and DBE (double balloon enteroscopy) allow light to be used in the inspection of small bowel and may replace previous radiological methods. WCE is more convenient than DBE for probing small bowel mucosal changes, but only DBE allows biopsy to be obtained in deep small bowel studies, and these two examinations can be considered complementary. Because of recently invented technologies, that might be widely available in the near future, endoscopy will play an increasingly important role in the management of IBD.

진공증착법에 의한 p-Zn0.51Cd0.49Se 박막의 성장 및 물리적 특성의 온도의존성

한동헌,윤은정,이정주,강광용 한국물리학회 2015 새물리 Vol.65 No.8

Zn0.51Cd0.49Se thin films with thicknesses of about 430 nm were deposited on indium-tin-oxide (ITO)-coated glass substrates by using thermal evaporation of high-purity ZnSe and CdSe mixed tablets in high vacuum. X-ray diffraction spectra showed that the Zn0.51Cd0.49Se thin films had mixed ZnSe and CdSe cubic zincblende structures with a lattice constant a = 6.077 °A and that the crystals were preferentially grown with a (111) orientation. From the results of X-ray photoelectron spectroscopy, the intensities of the binding energies of the Zn 2p core levels were found to be increased with increasing annealing temperature and those of the Cd 3d and the Se 3d core levels to be decreased. The optical energy band gap of the as-deposited Zn0.51Cd0.49Se thin film was 2.32 eV. Especially, the optical energy band gaps of Zn0.51Cd0.49Se thin films annealed in a vacuum electric furnace at temperatures from 200 ℃ to 500 ℃ were about 2.30 eV ~ 2.08 eV. From measurements of the photoinduced discharge characteristics, the hole drifts in the Zn0.51Cd0.49Se thin films and the hole concentrations were found to increase with increasing annealing temperature but the hole mobilities were found to decrease. 진공증착법으로 ITO (indium-tin-oxide) 기판 위에 두께 약 430 nm의 Zn0.51Cd0.49Se 박막을 제작하였다. X-선 회절 분석에 의하여 Zn0.51Cd0.49Se 박막은 CdSe와 ZnSe가 혼합된 정육면체 섬아연광 구조를 하고 있었으며, 그 성장방향은 (111) 방향으로 우선 성장하였다. X-선 광전자 분광 결과로부터, 열처리 온도 증가에 따라 Zn 2p에 대한 결합에너지의 피크 적분 강도는 증가하고, Cd 3d와 Se 3d에 대한 결합에너지의 피크 적분 강도는 감소하였다. 증착된 Zn0.51Cd0.49Se 박막의 광학적인 에너지 띠 간격은 2.32 eV이었다. 특히, 200 ℃ ~ 500 ℃로 진공 열처리한 박막의 광학적 에너지 띠 간격은 2.30 eV ~ 2.08 eV이었다. 광유기 방전 특성으로 분석한 Zn0.51Cd0.49Se 박막은 p-형 (양공표류)이며, 열처리 온도 증가에 따라 양공의 이동도는 감소하고, 양공의 농도는 증가함을 보였다.

진공증착법에 의한 n-Zn0:12Cd0:88Te 박막의 성장 및 물리적 특성의 온도의존성

김도형,손종윤,이정주,강광용 한국물리학회 2017 새물리 Vol.67 No.3

Zn$_{0.12}$Cd$_{0.88}$Te thin films of about 470 nm in thickness were deposited on indium-tin-oxide(ITO)-coated glass substrates by using thermal evaporation of high-purity ZnTe and CdTe mixed tablets in high vacuum. X-ray diffraction spectra showed that the Zn$_{0.12}$Cd$_{0.88}$Te thin films were preferentially grown with a (111) orientation. The structure of the Zn$_{0.12}$Cd$_{0.88}$Te crystal was a mixture of the ZnTe and the CdTe zincblende structures with lattice constants $a$ = 6.481 Å~to $a$ = 6.335 Å~ for the CdTe and $a$ = 6.070 Å~ for the ZnTe. The optical energy band gap, measured at room temperature, of the as-deposited Zn$_{0.12}$Cd$_{0.88}$Te thin film was 1.79 eV and decreased to about 1.73 eV and then increased to 2.23 eV upon annealing in a vacuum electric furnace at temperatures from 200 $^{\circ}$C to 400 $^{\circ}$C. The dynamic behavior of the charge carriers in the Zn$_{0.12}$Cd$_{0.88}$Te thin film was investigated by using the photoinduced discharge characteristics (PIDC) technique. 진공증착법으로 ITO (indium-tin-oxide) 기판 위에 약 470 nm 두께의 Zn$_{0.12}$Cd$_{0.88}$Te 박막을 성장하였다. X-선 회절 분석에 의하여 Zn$_{0.12}$Cd$_{0.88}$Te 박막의 격자상수는 CdTe (111)면에 대하여 $a$ = 6.481 Å이었고, CdTe(220)면과 CdTe(311)면에 대하여는 각각 $a$ = 6.477 Å과 $a$ = 6.335 Å이었으며, ZnTe (222)면에 대하여는 $a$ = 6.070Å이었다. 또한 CdTe와 ZnTe가 서로 혼합된 섬아연광 구조를 하고 있었으며, 그 성장방향은 (111) 방향으로 우선 성장됨을 알 수 있었다. 증착된 Zn$_{0.12}$Cd$_{0.88}$Te 박막에 대하여 실온에서 측정한 광학적인 에너지 띠 간격은 1.79 eV이었고, 열처리 온도가 증가함에 따라 감소하였다가 증가하였으며, 200 $^{\circ}$C, 300 $^{\circ}$C, 400 $^{\circ}$C로 열처리한 박막의 광학적 에너지 띠 간격은 1.73 eV $\sim$ 2.23 eV이었다. Zn$_{0.12}$Cd$_{0.88}$Te 박막 내의 전하운반자들의 동역학적 거동을 광유기 방전 특성(photoinduced discharge characteristics, PIDC)법으로 조사하였다.

진공증착법에 의한 p-Zn0.31Cd0.69Se 박막의 성장 및 열처리 온도에 따른 물리적 성질

한동헌,윤은정,이정주,강광용 한국물리학회 2015 새물리 Vol.65 No.1

Zn0.31Cd0.69Se films were prepared on indium-tin-oxide(ITO)-coated glass substrates by using thermal evaporation. X-ray diffraction spectra showed that the Zn0.31Cd0.69Se films had a mixed ZnSe and CdSe zincblende structure with a lattice constant a = 6.077 °A and that the crystals were preferentially grown with a (111) orientation. The optical energy band gap, measured at room temperature, of the as-deposited Zn0.31Cd0.69Se film was 2.05 eV and decreased to about 2.04 eV ~ 1.96 eV upon annealing in a vacuum electric furnace at temperatures from 200 ℃ to 500 ℃. The dynamical behavior of the charge carriers in the Zn0.31Cd0.69Se film was investigated by using photoinduced discharge characteristics (PIDC) techniques. 진공증착 법으로 ITO (indium-tin-oxide) 기판 위에 Zn0.31Cd0.69Se 박막을 제작하였다. X-선 회절 분석에 의하여 박막의 살창상수는 a = 6.077 °A으로 ZnSe와 CdSe의 섬아연광 구조를 하고 있었으며, 그 성장방향은 (111) 방향으로 우선 성장됨을 알 수 있었다. 증착된 Zn0.31Cd0.69Se 박막에 대하여 실온에서 측정한 광학적인 에너지 띠 간격은 2.05 eV이었고, 열처리 온도를 증가함에 따라 감소하였으며, 200 ℃ to 500 ℃로 열처리한 박막의 광학적 에너지 띠 간격은 2.04 eV ~ 1.96 eV이었다. Zn0.31Cd0.69Se 박막 내의 전하운반자들의 동역학적 거동을 광유기 방전 특성 (PIDC: photoinduced discharge characteristics) 방법으로 조사하였다.

진공증착법에 의한 p-Zn0.44Cd0.56S 박막의 성장 및 열처리 온도에 따른 물리적 성질

윤은정,한동헌,박창영,이정주,이종덕,강광용 한국물리학회 2014 새물리 Vol.64 No.11

Zn0.44Cd0.56S films were prepared on indium-tin-oxide (ITO)-coated glass substrates by using thermal evaporation. X-ray diffraction spectra showed that the Zn0.44Cd0.56S films had a mixture of CdS and ZnS zincblende structures with a lattice constant a = 5.658 Α ~and that the crystals were preferentially grown in a zincblende structure with a (111) orientation. The optical energy band gap, measured at room temperature, of the as-deposited Zn0.44Cd0.56S film was 2.72 eV and decreased to about 2.71 eV and then increased to 2.77 eV upon annealing in a vacuum electric furnace at temperatures from 200℃ to 500℃. The dynamical behavior of the charge carriers in the Zn0.44Cd0.56S film was investigated by using photoinduced discharge characteristics (PIDC) techniques. 진공증착 법으로 ITO (indium-tin-oxide) 기판 위에 Zn0.44Cd0.56S 박막을 제작하였다. X-선 회절 분석에 의하면 박막의 살창상수는 a = 5.658 \AA 으로 CdS와 ZnS의 혼합인 정육면체 섬아연광 구조를 이루고 있었으며, 성장방향은 (111) 방향의 정육면체 섬아연광 구조로 우선 성장됨을 알 수 있었다. 실온에서 Zn0.44Cd0.56S 박막의 광학적인 에너지 띠 간격은 2.72 eV이었고, 열처리 온도가 증가함에 따라 에너지 띠 간격은 감소하다가 증가하였으며, 200℃ 부터 500℃ 로 열처리한 박막의 광학적 에너지 띠 간격은 2.71 eV ~ 2.77 eV이었다. Zn0.44Cd0.56S 박막 내에 분포하고 있는 전하운반자들의 동역학적 거동을 광유기 방전 특성 (PIDC: photoinduced discharge characteristics) 측정방법으로 조사하였다.