HWE 방법에 의한 CdSe 박막 성장과 광전기적 특성

신영진,홍광준,이상열,유상하,서상석,문종대,김택성,정태수,신용진,이관교,김혜숙,정준우,정경아 한국센서학회 1997 센서학회지 Vol.6 No.4

The CdSe thin films were grown on the Si(100) wafers by a hot wall epitaxy method (HWE). The source and substrate temperature are 600� and 430 respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. From Hall data, the mobility was increased in the temperature range 30K to 150K by impurity scattering and decreased in the temperature range 150K to 293K by the lattice scattering. In order to explore the applicability as a photoconductive cell, we measured the sensitivity(γ), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of 1.39 X 10^7, the MAPD of 335mW, and the rise and decay time of l0ms and 9.5ms, respectively

광전도체의 CdS 단결정 성장과 물리적 특성

신영진,신현길,김택성,유기수,정태수,유평열,정철훈,이훈,신영신,홍관준 한국센서학회 1993 센서학회지 Vol.2 No.1

A CdS single crystal was grown by using sublimation method. Lattice constants, a_o and c_o, obtained by using extrapolation were 4.1318 Å and 6.7122 Å, respectively. The carrier density was ∼10^(23) m^(-3) and the mobility was 2.93X10^(-2) ㎡/V-sec from measured Hall data at room temperature. The mobility has a increasing tendency in proportion to T^½ from 33 K to 150 K and a decreasing tendency in proportion to T^(-2) from 180 K to room temperature. The short wavelength band peak measured from photocurrent was due to intrinsic transition, and the energy value of this peak was equal to the energy band gap of CdS photoconductor.

Chemical Bath Deposition 방법으로 제작한 CdSe 박마의 특성

신영진,홍광준,이상열,유상하,서상석,문종대,신현길,김택성,송정훈,유기수,정태수 한국센서학회 1993 센서학회지 Vol.2 No.1

Polycrystalline CdSe thin films were grown on ceramic substrate using a chemical bath deposition (CBD) method. They were annealed at various temperature and X-ray diffraction patterns were measured by X-ray diffractometer in order to study CdSe polycrystal structure. Using extrapolation method of X-ray diffraction patterns for the CdSe samples annealed in N₂ gas at 450℃ it was found hexagonal structure whose lattice parameters a_o and c_o were 4.302 A and 7.014 A, respectively. Its grain size was about 0.3 ㎛. Hall effect on this sample was measured by Van der Pauw method and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by piezo electric scattering at temperature range of 33 K and 200 K, and by polar optical scattering at temperature range of 200 K and 293 K. We measured also spectral response, sensitivity (γ), maximum allowable power dissipation and response time on these samples.

R . F . magnetron sputtering 법으로 제작한 ITO 박막의 특성

정운조,박계춘,유용택 한국센서학회 1995 센서학회지 Vol.4 No.2

Indium Tin Oxide (ITO) thin films have been fabricated by the rf magnetron sputtering technique with a target of a mixture In₂O₃ (90mol%) and SnO₂ (10mol%). We prepared ITO thin films with substrate temperature 100, 300, 400, 500℃ and post-annealing temperature 300, 400, 500℃. And w e analyzed X-ray diffraction patterns, electrical properties, transmission spectra and SEM photographs. As a result, the crystallinity, electrical conductivity and transmittance of ITO thin films were improved with increasing substrate temperature. I3ut, as increasing post-annealing temperature in air. conductivity of the film was decreased. When the ITO thin film was fabricated with substrate temperature of 500℃ and thickness of 3,000 Å, its resistivity and transmittance were about 2×10^(-4)Ωcm and 55% or more, respectively.

핵연료 피복관용 Zr 합금의 열처리에 다른 미세조직 및 부식특성

정용환,이명호,박상윤,김환철 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.12

The effects of final annealing temperature on microstructure and corrosion behavior of Zr-based alloys were investigated. Four kinds of Zr alleys were used for microstructural study and corrosion teat. Corrosion tests were carried out in static mini autoclave under 400℃ steam condition. Microstructures were analyzed by using TEM/EDS and image analyzer. The grain size and precipitate size of Zircaloy-4 increased with increasing the annealing temperature. As the annealing temperature increased, the corrosion resistance of Zircaloy-4 also increased due to the increase of precipitate size and grain size. Therefore, the precipitate size and grain size play an important role on the control of corrosion resistance of Zircaloy-4. However, it was considered from this study that the corrosion resistance of Nb-containing alloys would be controlled by the characteristics of beta phase rather than precipitate size.

핵연료 피복관용 Zircaloy-4 및 Zr-Nb 합금의 열처리에 따른 부식 및 기계적 특성 평가

김현길,정용환,이명호,윤영균 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.7

Effects of final annealing temperature on the corrosion and mechanical behavior, and microstructure were investigated for Zircaloy-4(Zr-1.3Sn-0.2Fe-0.1Cr), Alloy-1(Zr-0.4Nb-0.6Sn-0.4Fe-0.2Cu) and Alloy-2(Zr-1Nb). The corrosion tests were carried out in 360℃ water and 70 ppm LiOH solution in the static mini autoclaves. The mechanical tests were performed using the universal material test machine. The corrosion rate of Zircaloy-4 was not accelerated as the precipitates on Zircaloy-4 grew with the increase of annealing temperature after recrystallization. But the corrosion rate of Alloy-1 and 2 was accelerated due to the formation and growth of β-Zr phases with increasing the annealing temperature. Therefore, the corrosion resistance of the Zr-Nb alloy system could be improved by the control of heat treatment. It was also confirmed that the mechanical properties of Zr-based alloys were affected by the addition of alloying elements, the recrystallization, and the precipitation with annealing temperature.

Zr 합금의 석출물 및 부식특성에 미치는 Fe 와 Mn 첨가 영향

김현길,위명용,정용환,이명호,박상윤 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.11

In order to Investigate the effects of Fe and Mn on the precipitate and corrosion characteristics of Zr based alloys for nuclear fuel cladding, autoclave corrosion tests on the ternary(Zr-0.8Sn-X) alloys have been carried out at 360℃. The corrosion behavior of Zr-Sn-Fe alloy showed the cubic corrosion rate in the pre-transition region and the linear corrosion rate in the post-transition region. The good corrosion resistance in Zr-Sn-Fe alloy system was observed in Fe contents more than 0.2 wt%. The corrosion behavior of Zr-Sn-Mn alloy was significantly accelerated from the early stage. The lowest weight gain was observed in 0.2 wt% Mn. Based on the precipitate anallysis by TEM, it is thought that the corrosion of Zr-alloys would be related to the size of precipitate.

FET 형 용존 산소 센서의 유속에 의한 영향 조사와 감쇄 기법

김영진,손병기,이영철,정훈 한국센서학회 2001 센서학회지 Vol.10 No.3

Recently, FET type dissolved oxygen sensor was proposed to overcome the disadvantages of the amperometric Clark-type sensor. The inherent problem of the proposed sensor, however, is the flow dependence of the sensor perfomances since the proposed sensor detects the pH change in clue proximity to the working electrode. In this study, we decided the direction which minimize the flow effect in FIA(flow injection analysis) system. And a hydrodynamic buffer layer which can reduce the flow dependence were proposed. The suggested buffer-layers were formed onto sensing area and working electrode with mixed polymer matrix of TEOS(tetraethylorthosilicate) and DEDMS (diethoxydimethylsilane).

Zr-xNb 2원계 합금의 미세조직과 부식특성에 미치는 Nb 의 영향

김현길,임윤수,위명용,정용환 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.5

To develop the advanced Zr alloy for nuclear fuel cladding, the microstructure and corrosion characteristics of Zr-xNb binary alloys were studied of Nb addition. Microstructural observation and corrosion behavior of Zr-xNb alloys with niobium content were carried to develop an advanced nuclear fuel cladding materials. Niobium addition results in refining the final grain size, increasing precipitation in matrix and reducing corrosion resistance of the alloy in 360℃, 18.9㎫ water. The alloy with 0.2 wt.% Nb, especially, showed the highest corrosion resistance in this study which was related to columnar structure of the oxide and relatively high content of tetra-ZrO₂. This supports that the corrosion behavior of the Zr-Nb alloy significantly depended on the microstructure and composition of the oxide. mom the XRD analysis, SEM study and TEM observation on the oxide having equal oxide thickness, the 0.2 wt.% Nb alloy showing the best corrosion resistance had higher fraction of tetra-ZrO₂ and columnar structure than other alloys. Therefore, it is considered that the corrosion of Zr-xNb binary alloy would be controlled by the oxide characteristics like tetra-ZrO₂ and equiaxed structure.

다공질 박막을 이용한 FET 형 용존 산소 센서의 유속 의존성 개선

김영진,손병기,이영철,정훈 경북대학교 전자기술연구소 2001 電子技術硏究誌 Vol.22 No.2

FET type dissolved oxygen sensor was proposed to overcome the disadvantages of the amperometric Clark sensor. The inherent problem of the proposed sensor, however, is the flow dependence of the sensor performances since the proposed sensor detects the pH change in close proximity to the working electrode. In this study, a hydrodynamic porous thin film which can reduce the flow dependence were proposed the suggested porous thin film were formed onto sensing area and working electrode with mixed polymer matrix of TEOS and DEDMS.