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

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.

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.

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.

2 차원 정현파 가진을 받는 강체블록의 록킹진동에 있어서의 카오스 : 미끄럼이 없는 경우에 대하여 In the Case of No Sliding Occurrence

김지훈,김정호,양인영,정만용,양광영 한국산업안전학회 1999 한국안전학회지 Vol.14 No.2

This research deals with the non-linearities associated with impact and sliding for the rocking behavior of rigid block subjected to two dimensional excitation of horizontal and vertical direction. The non-linearities examined of impact between block and base: The transition of two governing rocking equations, the abrupt reduction in kinetic energy associated with impact. In this study, the rocking vibration system of two types are considered for several friction condition. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation at impact. The response analysis by non-dimensional rocking equation is carried out for the change of excitation amplitude. The chaos responses were discovered in the wide response region, particularly, in the case of high vertical excitation and their chaos characteristics are examined by Poincare map, power spectra and Lyapunov Exponent. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. Therefore, Poincare map will be a significant material in order to understand chaos of rocking system.

MEMS 및 센서 시스템 ; FET 형 이온센서용 무선원격측정시스템

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

A wireless telemetry measurement system, using ISFETs, was developed for environmental monitoring applications, industrial processes, medical treatments and so on. This system is composed of the measurement part located at remote site and a personal computer(PC) which control whole instrument process. The measurement part transmits measured data to the PC by RF transceiver, and transmitted data are analyzed and handled in the PC. Proposed system utilizing time division multiplexing for the transmission of 3channel ISFET signal. The measurement part has an identification number(ID) so that the PC controls many measurement parts separately. Experiments were performed using pH-ISFETs, and the implemented system operates well within designed specification and accuracy of 0.1 pH.

질소이온주입에 따른 생체안전성 티타늄 임플란트의 마모특성

변응선,최종운,손선희,정용수 한국산업안전학회 1999 한국안전학회지 Vol.14 No.4

In this study, plasma source ion implantation was used to improve the wear properties of biocompatible titanium implant. In order to observe the effect of ion energy and dose on wear property of titanium implant, pin-on-disk type wear tests in Hank's solution were carried out. The friction coefficient of ion implanted specimens were increased from 0.47 to 0.65 under high energy and ion dose conditions. As increasing ion energy and ion dose, the amount of wear was reduced.

화재완화를 위한 소듐 루프 건물의 구획화

김병호,권상운,정경채,김광락,황성태 한국산업안전학회 1998 한국안전학회지 Vol.13 No.3

Analysis on the study for the sodium fire mitigation was carried out using the CONTAIN-LMR code. Sodium loop building was partitioned into the many cells, in which the safety venting systems were installed for the purpose of improving the sodium fire safety and minimizing its effect on the sodium loop building. The effects of sodium fire on sodium loop building partitioned into the many cells and not partitioned were investigated. The peak pressure and temperature of each cell accompanied by sodium fire in sodium loop building partitioned were lower than those of sodium loop building not partitioned. In the case of partitioning sodium loop building, the pressures, temperatures and aerosols into cells were transferred through propagation path of CONTAIN-LMR sodium fire model simulated by this study, and the effect of sodium spray fire on sodium loop building was mitigated by partitioning building. In addition, the excessive rise of pressure into cells was prevented by installing the over-pressure exhaust valve and under-pressure exhaust valve on the flow path between cells.

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.