• 대한방사선기술학회지:방사선기술과학
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• 제10권1호
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• pp.43-47
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• 1987

Authors have tested on the characteristics, image qualities and clinical applications of Konica Hi-ortho X-ray film MGH. The results are as followed; 1. The speeds of KM/MG, MGH were as about 2.7 times, and those of KR/MG, MGH were as about 4.5 times as compared with LT-II/A and the tube voltage influenced upon KM/MG, MGH over 80 kVp, upon KR/MG, MGH over 90kVp. 2. Good image definition by the detection of Burger Phanton KM/MGH, KM/MG, and LT-II/A, and good I.Q. values by the detection of Hawlet Chart LT-II/A, KM/MGH, and KM/MG in that order. Therefore, MGH film could reduce the patient dose steeply, and furthermore, provide high image quality by the high contrast and then, it will be very useful to abdominal angiography and cerebral angiography.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.456-459
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• 2004

Analog film/screen systems have been being changed to a digital x-ray imaging device using direct conversion materials. Photocoductors for a direct detection flat-panel imager require high x-ray absorption, ionization and charge collection, low leakage current and large area deposition. In this work, $HgI_2$ films with excellent properties for x-ray detector were deposited by screen printing method. The thickness of $HgI_2$ film was about $150\;{\mu}m$. The passivation layer is fabricated using a-Se and parlyene, the both fabrication $HgI_2$ film were compared for analyzing the leakage current reduction. We measured electrical properties-leakage current, photosensitivity, SNR though I-V measurement, As the result, $HgI_2$ film using a-Se passivation layer had the greater

• 대한치과기공학회지
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• 제27권1호
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• pp.97-104
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• 2005

The effect of Nb on interfacial bonding characteristics of Ni-Cr alloy for porcelain fused to metal crown (PFM) has been studied in order to investigate oxide layer. A specimens, which is 0.8mm in thickness, were fired at 1,000$^{\circ}C$ with four tests such as air, vacuum, air for 5 minutes and vacuum for 5 minutes in order to examine an oxide behavior of alloy surface generated by the adding of Nb to be controlled at a rate of 0, 1, 3 and 5. It observed oxide film form of the fired specimens with optical microscope and scanning electron microscope (SEM), and chemical formation of them with energy disperse X-ray spectroscopy (EDX). The other specimens, which is 2mm in thickness, were fired at 1,000$^{\circ}C$ with air and vacuum in order to analyze the diffusion behaviors of alloy-porcelain interface by X-ray dot mapping. The results of this study were as follows: 1. The observation of microstructure of specimens by SEM showed that the more Nb content is high, the more much intermediate compound of rich Nb is observed. 2. The surface morphology of oxide film is most dense in 3% Nb. The heat treatment in air constitutes denser oxide film than heat treatment under vacuum. 3. The diffusion behavior of oxide layer by X-ray dot mapping showed that Si, Al of porcelain diffuse toward metal.

• 한국자기학회지
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• 제17권1호
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• pp.18-21
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• 2007

Pulsed laser deposition(PLD) 박막 증착법을 이용하여 hexagonal $HoMn_{1-x}-Fe_xO_3$(x=0.0, 0.05) 물질을 박막으로 $Pt/Ti/SiO_2/Si$ 기판 위에 증착하였다. 또한 x-ray diffraction(XRD), atomic force microscopy(AFM), scanning electron microscope(SEM), 및 x-ray photoelectron spectroscopy(XPS)를 통하여 박막의 결정학적 및 미세 구조를 분석하였고, conversion electron $M\"{o}ssbauer$ spectroscopy(CEMS)를 이용하여 자기적 특성에 관해 연구하였다. 결정구조는 hexagonal 구조로써 space group이 $P6_3cm$로 분석되었고, single crystal과는 달리 (110) 방향으로 우선 배향성을 가지고 증착되었다. $HoMn_{0.95}Fe_{0.05}O_3$ 박막의 경우 single crystal과 비교했을 때 hexagonal unit cell의 $c_0$ 축은 일정하나 $a_0$ 축은 다소 감소함으로 분석되었다. 이는 박막 증착에 사용된 $Pt/Ti/SiO_2/Si$ 기판과의 lattice mismatch 때문으로 해석된다. Fe가 미량 치환된 $HoMn_{0.95}Fe_{0.05}O_3$ 박막을 상온에서 CEMS 측정을 수행한 결과, $HoMn_{0.95}^{57}Fe_{0.05}O_3$ 분말의 경우 magnetic $T_N$이 72K 부근이므로, 상온에서 doublet absorption spectrum이 관측되었고, 전기사중극자 분열값(quadrupole splitting; ${\Delta}E_Q$)이 $1.62{\pm}0.01mm/s$로 비교적 큰 값을 가짐을 확인하였다.

• 한국결정성장학회지
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• 제24권3호
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• pp.94-98
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• 2014

$LiCoO_2$는 박막 베터리의 양극재료로써 많은 관심을 받고 있다. 본 연구에서는 스핀 코터를 이용한 졸-겔 합성공정과 열처리 과정에 의해서 Au 지지체 위에 $LiCoO_2$ 박막을 합성하였다. 합성된 박막의 구조는 X-선회절분석, 라만분광 광도계를 이용하여 분석하였다. 박막의 입자 형태는 전자현미경에 의해 관찰하였다. X-선회절분석, 라만분광광도계의 결과로부터, $550^{\circ}C$와 $750^{\circ}C$에서 합성된 박막은 스피넬구조와 층상 암염 형 구조를 가지는 박막으로 보이며, $650^{\circ}C$에서 합성된 박막은 층상 암염 형 구조와 스피넬 구조가 혼재되어져 있는 것으로 생각된다. $750^{\circ}C$에서 합성된 박막은 다른 낮은 온도에서 합성된 박막보다 큰 결정질의 균일한 분포의 입자를 가지는 것으로 확인되었다.

• Current Photovoltaic Research
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• 제5권1호
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• pp.20-24
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• 2017

Recently, three-dimensional (3D) light harvesting structures are highly attracted because of their high light harvesting capacity and charge collection efficiencies. In this study, we have fabricated $Cu_2ZnSn(S_xSe_{1-x})_4$ based 3D thin film solar cells on PR patterned Molybdenum (Mo) substrates using photolithography technique. Specifically, Mo patterns were deposited on PR patterned Mo substrates by sputtering and the thin Cu-Zn-Sn stacked layer was deposited over this Mo patterns by sputtering technique. The stacked Zn-Sn-Cu precursor thin films were sulfo-selenized to form CZTSSe pattern. Finally, CZTSSe absorbers were coated with thin CdS layer using chemical bath deposition and ZnO window layer was deposited over CZTSSe/CdS using DC sputtering technique. Fabricated 3-D solar cells were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) analysis, Field-emission scanning electron microscopy (FE-SEM) to study their structural, compositional and morphological properties, respectively. The 3% efficiency is achieved for this kind of solar cell. Further efforts will be carried out to improve the performance of solar cell through various optimizations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.398-398
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• 2013

The electronic properties and the local structure of tantalum oxide thin film with variation of oxygen flow rate ranging from 9.5 to 16 sccm (standard cubic centimeters per minute) have been investigated by X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results show that the Ta4f spectrum for all films consist of the strong spin-orbit doublet $Ta4f_{7/2}$ and $Ta4f_{5/2}$ with splitting of 1.9 eV. The oxygen flow rate of the film results in the appearance of new features in the Ta4f at binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV, these peaks attribute to $Ta^{1+}$, $Ta^{2+}$, $Ta^{4+}$/$Ta^{2+}$, and $Ta^{5+}$, respectively. Thus, the presence of non-stoichiometric state from tantalum oxide ($TaO_x$) thin films could be generated by the oxygen vacancies. The REELS spectra suggest the decrease of band gap for tantalum oxide thin films with increasing the oxygen flow rate. The absorption coefficient ${\mu}$ and its fine structure were extracted from the fluorescence mode of extended X-ray absorption fine structure (EXAFS) spectra. In addition, bond distances (r), coordination numbers (N) and Debye-Waller factors (${\sigma}^2$) each film were determined by a detailed of EXAFS data analysis. EXAFS spectrapresent both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the increase of oxygen flow rate.

• Radiation Oncology Journal
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• 제16권4호
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• pp.505-515
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• 1998

목적 : 본 연구는 상용되는 CEA TVS 필름의 감성과 현탁재질을 Kodak X-Omat V 필름과 비교하여 이해하는 것을 목표로 한다. 대상 및 방법 : 이 목표를 위해 전자, 광자 및 가시광선의 복합방사선에 노출된 X 선 필름의 특성커브(H & D curve)에 대한 해석적 표현식을 유도해 내었다. 이 수학적 공식은 반응율 및 target-hit 이론에 근거하여 전개되었다. 기존의 표현식과는 다르게 이것은 필름의 광밀도를 AgBr 입자크기 및 함유량과 같은 현탁재질과 관련시킨다. 또한 광자와 전자에 대한 것과 상대하여 필름의 가시광선에 대한 반응성을 특징짓는 정량적 인자(양자)를 유도해 내었다. 즉, 우리는 필름의 현탁재질을 그것의 감성을 근거로 알게 해 주는 수식과 양자를 유도해 내었다. 이러한 해석적인 연구의 사용을 보이기 위하여 CEA와 Kodak Verification 필름을 전자, 광자, 및 가시광선으로 이루어진 복합방사선에 노출시키고 그 실험결과를 적절히 해석하였다. 결과 : 우리는 아래를 논증하였다. (1) 임계밀도는 AgBr 함유량이 증가함에 따라 증가한다. (2) 필름이 가시광선에 노출되었을 때 문턱선량까지 도달하는 데에 걸리는 시간은 AgBr 입자크기가 증가함에 따라 감소한다. (3) Kodak 필름이 보다 더 큰 입자를 함유한 반면 CEA 필름은 더 많은 양의 AgBr을 함유하고 있다. 이러한 결과는 차후에 필름제작자가 제공한 자료로 뒷받침되었다. 결론 : 본 연구는 X선 필름의 반응성을 그 현탁재질에 관련하여 이해하기 위한 해석적, 실험적인 도구를 제시하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.158-158
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• 2009

This paper focuses on improving organic thin film transistor (OTFT) characteristics by controlling the self-organization of pentacene molecules with an alignable high-dielectric-constant film. The process, based on the growth of pentacene film through high-vacuum sublimation, is a method of self-organization using ion-beam (IB) bombardment of the $HfO_2/Al_2O_3$ surface used as the gate dielectric layer. X-ray photoelectron spectroscopy indicates that the IB raises the rate of the structural anisotropy of the $HfO_2/Al_2O_3$film, and X-ray diffraction patterns show the possibility of increasing the anisotropy to create the self-organization of pentacene molecules in the first polarized monolayer. An effective mobility of $2.3{\times}10^{-3}cm^2V^{-1}s^{-1}$ was achieved, which is significantly different from that of pentacene films that are not aligned. The proposed OTFT devices with an ultrathin $HfO_2$ structure as the gate dielectric layer were operated at a gate voltage lower than 5 V.

• 센서학회지
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• 제16권2호
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• pp.85-90
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• 2007

This paper presents the growth conditions and characteristics of polycrystalline 3C-SiC (silicon carbide) thin films for M/NEMS applications related to harsh environments. The growth of the 3C-SiC thin film on the oxided Si wafers was carried out by APCVD using HMDS (hexamethyildisilane: $Si_{2}(CH_{3})_{6})$ precursor. Each samples were analyzed by XRD (X-ray diffraction), FT-IR (fourier transformation infrared spectroscopy), RHEED (reflection high energy electron diffraction), GDS (glow discharge spectrometer), XPS (X-ray photoelectron spectroscopy), SEM (scanning electron microscope) and TEM (tunneling electro microscope). Moreover, the electrical properties of the grown 3C-SiC thin film were evaluated by Hall effect. From these results, the grown 3C-SiC thin film is very good crystalline quality, surface like mirror and low defect. Therefore, the 3C-SiC thin film is suitable for extreme environment, Bio and RF M/NEMS applications in conjunction with Si fabrication technology.