• Title/Summary/Keyword: 펄스 레이저 증착법

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Growth Conditions of $SrTiO_3 $ Film on Textured Metal Substrate for $YBa_2CU_3O_{7-\delta}$ Coated Conductor ($YBa_2CU_3O_{7-\delta}$ coated Conductor 완충층으로의 응용을 위한 $SrTiO_3 $ 박막의 성장 조건)

  • Chung, J.K.;Ko, R.K.;Song, K.J.;Park, C.;Kim, C.J.
    • Korean Journal of Crystallography
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    • v.14 no.2
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    • pp.51-55
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    • 2003
  • SrTiO₃ (STO) thin fims were deposited on the biaxially textured Ni-3 wt%W alloy substrates to be used as a single buffer layer for YBa₂CU₃O/sub 7-8/(YBCO) coated conductor. Thin films of YBCO and STO were deposited using pulsed laser. The deposition condition for epitaxial growth of STO on the textured metal was identified, and YBCO coated conductor with a single STO buffer layer with critical current density of 1.2 MA㎠ at 77 K under zero magnetic field and critical temperature of 86 K, was fabricated.

Photoluminescence Characteristics of the ZnGa2O4 Phosphor Thin Films as a Function of Post-annealing Temperature (후열처리 온도에 따른 ZnGa2O4 형광체 박막의 발광 특성)

  • Yi, Soung-Soo;Jeong, Jung-Hyun
    • Journal of Sensor Science and Technology
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    • v.11 no.1
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    • pp.60-65
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    • 2002
  • $ZnGa_2O_4$ thin film phosphors have been deposited using a pulsed laser deposition method on Si(100) substrates at a substrate temperature of $550^{\circ}C$ with oxygen pressures of 100mTorr, and subsequently to investigate their photoluminescence characteristics after post-annealed at $600^{\circ}C$ and $700^{\circ}C$. As a result for X-ray diffraction, $Ga_2O_3$ shape appeared with increasing annealing temperature. The luminescent spectra show a broad band extending from 350 to 600nm peaking at 460nm. A post-annealing treatment of $ZnGa_2O_4$ thin films led to the different shape of luminescent intensity and grain size.

Photoluminescence Behaviors of the ZnGa2O4 Phosphor Thin Films on Al2O3 substrates as a Function of Oxygen Pressures (Al2O3 기판위에 증착한 ZnGa2O4 형광체 박막의 산소분압에 따른 형광특성)

  • Yi, Soung-Soo
    • Journal of Sensor Science and Technology
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    • v.11 no.2
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    • pp.118-123
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    • 2002
  • $ZnGa_2O_4$ thin film phosphors have been deposited using a pulsed laser deposition technique on $Al_2O_3$(0001) substrates at a substrate temperature of $550^{\circ}C$ with various oxygen pressures 100, 200 and 300 mTorr. The films grown under different growth oxygen pressures have been characterized using microstructural and luminescent measurements. The different photoluminescence (PL) characteristics with the increase in oxygen pressures may result from the change of the crystallinity and the composition ratio of Zn and Ga in the films. The luminescent spectra show a broad band extending from 300 to 600 nm peaking at 460 nm. The PL brightness data obtained from the $ZnGa_2O_4$ films grown under optimized conditions have indicated that the sapphire is a promising substrate for the growth of high quality $ZnGa_2O_4$ thin film phosphor.

Dependence of Electrical and Optical Properties on Substrate Temperatures of AZO Thin Films (기판온도에 의한 AZO 박막의 전기적 및 광학적 특성 변화)

  • Seong-Jun Kang;Yang-Hee Joung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.6
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    • pp.1067-1072
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    • 2023
  • We prepared AZO (Al2O3 : 3 wt %) thin films according to the substrate temperature using the pulsed laser deposition method and the structural, electrical, and optical properties of the thin films were investigated. The AZO thin film deposited at 400℃ showed the best (002) orientation and the FWHM was 0.38°. As a result of the investigation of electrical properties, it was confirmed that the carrier concentration and mobility increased and the resistivity decreased as the substrate temperature increased. The average transmittance in the visible light region showed a high value of 85% or more regardless of the substrate temperature. The Burstein-Moss effect, in which the carrier concentration would increase with increasing substrate temperature thereby widening the energy band gap, was also observed. The resistivity and the figure of merit of the AZO thin film deposited at a substrate temperature of 400℃ were 6.77 × 10-4 Ω·cm and 1.02 × 104-1·cm-1 respectively, showing the best value.

Effect of the Deposition Time onto Structural Properties of Cu2ZnSnS4 Thin Films Deposited by Pulsed Laser Deposition (펄스 레이저 증착법으로 제작한 Cu2ZnSnS4 박막의 구조 특성 변화에 대한 증착 시간 효과)

  • Byeon, Mirang;Bae, Jong-Seong;Hong, Tae-Eun;Jeong, Euh-Duck;Kim, Shinho;Kim, Yangdo
    • Korean Journal of Materials Research
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    • v.23 no.1
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    • pp.7-12
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    • 2013
  • The $Cu_2ZnSnS_4$ (CZTS) thin film solar cell is a candidate next generation thin film solar cell. For the application of an absorption layer in solar cells, CZTS thin films were deposited by pulsed laser deposition (PLD) at substrate temperature of $300^{\circ}C$ without post annealing process. Deposition time was carefully adjusted as the main experimental variable. Regardless of deposition time, single phase CZTS thin films are obtained with no existence of secondary phases. Irregularly-shaped grains are densely formed on the surface of CZTS thin films. With increasing deposition time, the grain size increases and the thickness of the CZTS thin films increases from 0.16 to $1{\mu}m$. The variation of the surface morphology and thickness of the CZTS thin films depends on the deposition time. The stoichiometry of all CZTS thin films shows a Cu-rich and S-poor state. Sn content gradually increases as deposition time increases. Secondary ion mass spectrometry was carried out to evaluate the elemental depth distribution in CZTS thin films. The optimal deposition time to grow CZTS thin films is 150 min. In this study, we show the effect of deposition time on the structural properties of CZTS thin film deposited on soda lime glass (SLG) substrate using PLD. We present a comprehensive evaluation of CZTS thin films.

Effect of Targets on Synthesis of Aluminum Nitride Thin Films Deposited by Pulsed Laser Deposition (펄스레이저법으로 증착 제조된 AlN박막의 타겟 효과)

  • Chung, J.K.;Ha, T.K.
    • Transactions of Materials Processing
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    • v.29 no.1
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    • pp.44-48
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    • 2020
  • Aluminum nitride (AlN), as a substrate material in electronic packaging, has attracted considerable attention over the last few decades because of its excellent properties, which include high thermal conductivity, a coefficient of thermal expansion that matches well with that of silicon, and a moderately low dielectric constant. AlN films with c-axis orientation and thermal conductivity characteristics were deposited by using Pulsed Laser Deposition (PLD). The epitaxial AlN films were grown on sapphire (c-Al2O3) single crystals by PLD with AlN target and Y2O3 doped AlN target. A comparison of different targets associated with AlN films deposited by PLD was presented with particular emphasis on thermal conductivity properties. The quality of AlN films was found to strongly depend on the growth temperature that was exerted during deposition. AlN thin films deposited using Y2O3-AlN targets doped with sintering additives showed relatively higher thermal conductivity than while using pure AlN targets. AlN thin films deposited at 600℃ were confirmed to have highly c-axis orientation and thermal conductivity of 39.413 W/mK.

Pulsed laser deposition of YBCO thin films using modified melt-textured grown targets (Modified melt-textured growth 법으로 제작한 타겟을 사용한 YBCO 박막의 펄스레이저 증착)

  • Kim, Chang-Hoon;Kim, In-Tae;Hong, Kug-Sun;Kim, Young-Hwan;Choi, Sang-Sam;Hahn, Taek-Sang
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.115-119
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    • 1999
  • Ba$_2Cu_3O_{7-{\delta}}$ (YBCO) thin films were deposited by pulsed laser deposition using differently prepared targets: One was a conventionally solid-state sintered (SSS) target and the other was a modified melt-textured grown (MTC) target. Compared with SSS targets, MTG targets showed a well-connected microstructure consisting of much larger grains and the surface was Bess roughened with the cumulative laser incidence. YBCO films deposited from MTC targets showed a denser and smoother surface of the basal film than the case of SSS targets. The investigations of ${\alpha}$-axis outgrowths in the films indicated that the deposition using MTG targets would result in a more homogeneous and stable film growth as compared to the SSS targets. Also, TEM analysis revealed that the film deposited from MTG targets had a less granular microstructure that would reduce weak-link effects in the film.

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Characteristics of $(Pb_{1-x}La_x)(Zr_{0.5}Ti_{0.5})O_3$ thin films as a function of La content ($(Pb_{1-x}La_x)(Zr_{0.5}Ti_{0.5})O_3$ 박막의 La 치환량에 따른 특성)

  • Jang, Nak-Won;Lee, Seong-Hwan;Yi, Dong-Young;Kim, Dong-Hun
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.8
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    • pp.894-900
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    • 2006
  • The electrical characteristics associated with crystal structure changes as a function of La content for $(Pb_{1-x}La_x)(Zr_{0.5}Ti_{0.5})O_3$ thin films were investigated for applications in memory capacitors. Tetragonality of PLZT films decreased with increasing La content. Thin films with La $\geq$ 20 mol% were found to be cubic. Films with La $\geq$ 12 mol% exhibited broader dielectric peaks compared to those of bulk ceramics and behaved as relaxer ferroelectrics. Tetragonal PLZT film with 12 mol% La had a dielectric constant maximum of 1330 at room temperature and a charge storage density of ${\sim}18{\mu}C/cm^2$ at 5 V. Decrease in coercive field and remnant polarization with increase in La content were resulting from less dipolar response caused by the decreased crystal anisotropy. The leakage current densities $<10^{-8}A/cm^2$ up to 5 V bias voltage were observed for the films with La $\geq$ 14 mol%.

The Effect of Thermal Annealing and Growth of ZnO Thin Film by Pulesd Laser Deposition (펄스 레이저 증착(PLD)법에 의한 ZnO 박막 성장과 열처리 효과)

  • Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.160-162
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    • 2003
  • ZnO epilayer were synthesized by the pulesd laser deposition(PLD) process on $Al_2O_3$ substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193nm) excimer laser. The substrate temperatures was $400^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are $8.27{\times}10^{16}\;cm^{-3}\;and\;299\;cm^2V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;3.3973\;eV\;-\;(2.69{\times}10^{-4}\;eV/K)T^2/(T\;+\;463K)$. After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Zn}$, Vo, $Zn_{int}$, and $O_{int}$ obtained by PL measurements were classified as a donors or accepters type.

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Preparation and Characterization of Multiferroic $0.7BiFeO_3-0.3BaTiO_3$ Thin Films by Pulsed Laser Deposition (펄스 레이저 증착법으로 제작된 다강체 $0.7BiFeO_3-0.3BaTiO_3$ 박막의 특성 연구)

  • Kim, Kyung-Man;Yang, Pan;Zhu, Jinsong;Joh, Young-Gull;Lee, Hee-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.88-88
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    • 2009
  • $BiFeO_3$(BFO), when forming a solid solution with $BaTiO_3$(BTO), shows structural transformations over the entire compositional range, which not only gives a way to increase structural stability and electrical resistivity but also applies a means to have better ferromagnetic ordering. In this respect, we have prepared and studied 0.7BFO-0.3BTO thin films on $Pt(111)/TiO_2/SiO_2/Si$ substrates by pulsed laser deposition. Various deposition parameters, such as deposition temperature and oxygen pressure, have been optimized to get better quality films. Based on the X-ray diffraction results, thin films were successfully deposited at the temperature of $600^{\circ}C$ and an oxygen partial pressure of 10mTorr. The dielectric, ferroelectric, and magnetic properties have then been characterized. It was found that the films deposited under lower oxygen pressure corresponded to lower leakage current. Magnetism measurement showed an induced ferromagnetism. The microstructures associated with. the magnetic and dielectric properties of this mixed-perovskite solid solutions were observed by transmission electron. microscopy, which revealed the existence of complicated ferroelectric domains, suggested that the weak spontaneous magnetization was closely associated with the decrease in the extent of rhombohedral distortion by a partial substitution of $BaTiO_3$ for $BiFeO_3$.

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