• 제목/요약/키워드: Doped TiO2 thin films

검색결과 33건 처리시간 0.024초

Enhanced Self-Cleaning Performance of Ag-F-Codoped TiO2/SiO2 Thin Films

  • Kim, Byeong-Min;Kim, Jung-Sik
    • 한국재료학회지
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    • 제28권11호
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    • pp.620-626
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    • 2018
  • Highly self-cleaning thin films of $TiO_2-SiO_2$ co-doped with Ag and F are prepared by the sol-gel method. The asprepared thin films consist of bottom $SiO_2$ and top $TiO_2$ layers which are modified by doping with F, Ag and F-Ag elements. XRD analysis confirms that the prepared thin film is a crystalline anatase phase. UV-vis spectra show that the light absorption of $Ag-F-TiO_2/SiO_2$ thin films is tuned in the visible region. The self-cleaning properties of the prepared films are evaluated by a water contact angle measurement under UV light irradiation. The photocatalytic performances of the thin films are studied using methylene blue dye under both UV and visible light irradiation. The $Ag-F-TiO_2/SiO_2$ thin films exhibit higher photocatalytic activity under both UV and visible light compared with other samples of pure $TiO_2$, Ag-doped $TiO_2$, and F-doped $TiO_2$ films.

SnO2가 도핑된 TiO2 박막의 합성 및 광촉매 효과 (Synthesis and Photoactivity of SnO2-Doped TiO2 Thin Films)

  • 정미원;곽윤정
    • 한국세라믹학회지
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    • 제44권11호
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    • pp.650-654
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    • 2007
  • [ $SnO_2$ ]-doped $TiO_2$ thin films were prepared from tin (IV) bis (acetylacetonate) dichloride and titanium diisopropoxide bis (acetylacetonate) with pluronic P123 or degussa P25 as a structural-directing agent. These hydrolyzed sol were spin coated onto Si(100) wafer substrate. The microstructure, morphology and bonding states of thin films were studied by field-emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of these films was investigated by using indigo carmine solution.

RF 마그네트론 스퍼터링법으로 성장시킨 0.5% Ce-doped Ba(Zr0.2Ti0.8)O3 (BCZT) 박막의 열처리 특성분석 (Characterization of the Annealing Effect of 0.5 % Ce-doped Ba(Zr0.2Ti0.8)O3 Thin Films Grown by Rf Magnetron Sputtering Method)

  • 최원석;박용섭;이준신;홍병유
    • 한국전기전자재료학회논문지
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    • 제16권5호
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    • pp.361-364
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    • 2003
  • It was investigated that the structural and electrical Properties of Ce-doped Ba(Zr$_{x}$Ti$_{1-x}$ )O$_3$ (BCZT) thin films with a mole fraction of x=0.2 and a thickness about 100 nm. BCZT films were prepared on Pt/Ti/SiO$_2$/Si substrate by a RF magnetron sputtering system. We have measured the thickness profile with Ar/O$_2$ ratio and the surface roughness. It was observed that the oxygen gas, which introduced during the film deposition, have an influence on the roughness of the film and the film roughness was reduced by annealing from 2.33 nm to 2.02 nm (RMS at 500 $^{\circ}C$, Ar:6 sccm, $O_2$:6 sccm). It was found that annealing procedure after top electrode deposit can reduce the dissipation factor.

Ti 첨가 Al2O3 코팅층의 두께와 열처리 조건이 LiCoO2 양극 박막의 미세구조와 전기화학적 특성에 미치는 영향 (Effect of Ti-Doped Al2O3 Coating Thickness and Annealed Condition on Microstructure and Electrochemical Properties of LiCoO2 Thin-Film Cathode)

  • 최지애;이성래;조원일;조병원
    • 한국재료학회지
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    • 제17권8호
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    • pp.447-451
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    • 2007
  • We investigated the dependence of the various annealing conditions and thickness ($6\sim45nm$) of the Ti-doped $Al_2O_3$ coating on the electrochemical properties and the capacity fading of Ti-doped $Al_2O_3$ coated $LiCoO_2$ films. The Ti-doped-$Al_2O_3$-coating layer and the cathode films were deposited on $Al_2O_3$ plate substrates by RF-magnetron sputter. Microstructural and electrochemical properties of Ti-doped-$Al_2O_3$-coated $LiCoO_2$ films were investigated by transmission electron microscopy (TEM) and a dc four-point probe method, respectively. The cycling performance of Ti-doped $Al_2O_3$ coated $LiCoO_2$ film was improved at higher cut-off voltage. But it has different electrochemical properties with various annealing conditions. They were related on the microstructure, surface morphology and the interface condition. Suppression of Li-ion migration is dominant at the coating thickness >24.nm during charge/discharge processes. It is due to the electrochemically passive nature of the Ti-doped $Al_2O_3$ films. The sample be made up of Ti-doped $Al_2O_3$ coated on annealed $LiCoO_2$ film with additional annealing at $400^{\circ}C$ had good adhesion between coating layer and cathode films. This sample showed the best capacity retention of $\sim92%$ with a charge cut off of 4.5 V after 50 cycles. The Ti-doped $Al_2O_3$ film was an amorphous phase and it has a higher electrical conductivity than that of the $Al_2O_3$ film. Therefore, the Ti-doped $Al_2O_3$ coated improved the cycle performance and the capacity retention at high voltage (4.5 V) of $LiCoO_2$ films.

N 도핑된 TiO2 광촉매 박막의 제조 및 특성분석 (Manufacturing and Characterization of N-doped TiO2 Photocatalytic Thin Film)

  • 박상원;남수경;허재은
    • 한국환경과학회지
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    • 제16권6호
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    • pp.683-688
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    • 2007
  • In this study, N doped $TiO_2$ (TiO-N) thin film was prepared by DC magnetron sputtering method to show the photocatalytic activity in a visible range. Various gases (Ar, $O_2\;and\;N_2$) were used and Ti target was impressed by 1.2 kW -5.8 kW power range. The hysteresis of TiO-N thin film as a function of discharge voltage wasn't observed in 1.2 and 2.9kW of applied power. Cross sections and surfaces of thin films by FE-SEM were tiny and dense particle sizes of both films with normal cylindrical structures. XRD pattern of $TiO_2$ and TiO-N thin films was appeared by only anatase peak. Red shift in UV-Vis adsorption spectra was investigated TiO-N thin film. Photoactivity was evaluated by removal rate measurement of suncion yellow among reactive dyes. The photodegradation rate of $TiO_2$ thin film on visible radiation was shown little efficiency but TiO-N was about 18%.

동시 스퍼터링법을 이용하여 Cu 도핑한 TiO2 박막의 구조적, 광학적 및 광분해 특성 (Structural, Optical and Photocatalyst Property of Copper-doped TiO2 Thin Films by RF Magnetron Co-sputtering)

  • 허민찬;홍현주;한성홍;김의정;이충우;주종현
    • 한국광학회지
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    • 제17권1호
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    • pp.104-109
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    • 2006
  • 동시 스퍼터링법으로 $TiO_2$ 박막과 구리를 도핑한 Cu/$TiO_2$ 박막을 제작하고, 금속의 도핑과 열처리 온도에 따른 구조적, 광학적, 광분해 특성을 조사하였다. XRD 측정 결과 구리 도핑의 경우에 입자의 결정 크기가 증가하였으며, SEM 결과 입자들의 크기가 균일하고 입자들의 뭉침이 더 작은 것을 확인 할 수 있었다. $900^{\circ}C$에서 열처리한 박막의 흡수단은 아나타제에서 루타일로의 상전이에 의해 밴드갭의 변화로 장파장 영역으로 이동하였고, 또한 입자 크기 증가에 따라 투과율이 급격히 감소하였다. Cu/$TiO_2$ 박막들은 순수$TiO_2$ 박막보다 광분해 특성이 더 우수하였다.

Preparation of Highly Visible-Light Photocatalytic Active N-Doped TiO2 Microcuboids

  • Zhao, Kang;Wu, Zhiming;Tang, Rong;Jiang, Yadong
    • 대한화학회지
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    • 제57권4호
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    • pp.489-492
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    • 2013
  • N-doped $TiO_2$ microcuboids were successfully prepared by a simple one-pot hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. It was found that the N-doped $TiO_2$ microcuboids enhanced absorption in the visible light region, and exhibited higher activity for photocatalytic degradation of model dyes. Based on the experimental results, a visible light induced photocatalytic mechanism was proposed for N-doped anatase $TiO_2$ microcuboids.

동시 스퍼터링법에 이용하여 제작한 TiO2와 Ag/TiO2 광학 박막의 특성 (Characteristics of TiO2 and Ag/TiO2 optical thin film by Co-sputtering method)

  • 김상철;한성홍;김의정;이충우;주종현;김구철
    • 한국광학회지
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    • 제16권2호
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    • pp.168-173
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    • 2005
  • 고주파 마그네트론 동시 스퍼터링법을 이용하여 $TiO_2$ 박막에 Ag를 도핑한 $Ag/TiO_2$ 박막을 제작하고, 열처리 온도에 따른 박막의 물리적, 화학적 특성을 조사하였다. XRD 측정 결과로부터 금속을 도핑한 박막이 순수 $TiO_2$ 박막보다 결정크기가 더 작은 것을 확인하였으며, SEM 측정 결과로부터 $Ag/TiO_2$ 박막은 순수 $TiO_2$ 박막보다 골자의 크기가 작고 균일하다는 것을 알 수 있었다. 제작된 박막은 가시광선 영역에서 높은 투과율을 나타내었다. $600^{\circ}C$에서 열처리한 박막은 아나타제 결정상이 나타났으며, $900^{\circ}C$에서 열처리한 박막은 아나타제와 루타일상이 혼합되어 나타났다 특히, $900^{\circ}C$에서 열처리한 경우 아나타제에서 루타일로의 상전이에 따른 밴드갭 에너지의 변화에 의해 박막의 흡수단이 장파장 영역으로 이동하였다. 또한 박막 내의 흡수와 산란효과에 의해 투과율이 감소하였다. $Ag/TiO_2$ 박막의 광활성은 순수 $TiO_2$ 박막보다 우수함을 알 수 있었다.

유기 금속 화학 기상 증착법으로 제조된 자성반도체 Til-xCoxO2 박막의 Co 조성 변화에 따른 미세구조 및 자기적 특성 (Microstructure and Magnetic Properties of Til-xCoxO2 Diluted Magnetic Semiconductor Thin Films with Various Co Concentrations by Metal Organic Chemical Vapor Deposition)

  • 성낙진;오영남;조채룡;윤순길
    • 한국재료학회지
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    • 제13권11호
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    • pp.737-741
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    • 2003
  • Polycrystalline $Ti_{l-x}$ $Co_{x}$ $O_2$thin films on $SiO_2$ (200 nm)/Si (100) substrates were prepared using liquid-delivery metalorganic chemical vapor deposition. Microstructures and ferromagnetic properties were investigated as a function of doped Co concentration. Ferromagnetic behaviors of polycrystalline films were observed at room temperature, and the magnetic and structural properties strongly depended on the Co distribution, which varied widely with doped Co concentration. The annealed $Ti_{l-x}$ $Co_{x}$ $O_2$thin films with $x\leq$0.05 showed a homogeneous structure without any clusters, and pure ferromagnetic properties of thin films are only attributed to the X$l-x_{l-x}$ $Co_{x}$X$O_2$phases. On the other hand, in case of thin films above x = 0.05, Co-rich clusters formed in a homogeneous $Ti_{l-x}$ $Co_{x}$ $O_2$phase, and the overall ferromagnetic (FM) properties depended on both FMTCO and FMCo. Co-rich clusters with about 10-150 nm size decreased the value of Mr (the remanent magnetization) and increased the saturation magnetic field.

비휘발성 메모리 소자응용을 위한 Eu 첨가량에 따른 BET 박막의 강유전 특성 (Ferroelectric Properties of Bi3.25La0.75Ti3O12 Thin Films with Eu Contents for Non-volatile Memory Device Application)

  • 김경태;김종규;우종창;김관하;김창일
    • 한국전기전자재료학회논문지
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    • 제20권3호
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    • pp.223-227
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    • 2007
  • The effect of Eu contents on the ferroelectric properties of $Bi_{4-x}Eu_xTi_3 O_{12}$ (BET) thin films has been investigated. Bismuth Europium titanate thin films with a Eu contents were prepared on the $Pt/Ti/SiO_2/Si$ substrate by metal-organic decomposition technique. The structure and the morphology of the films were analyzed using X-ray diffraction (XRD) and field emission scanning microscopy (FE-SEM), respectively. From the XRD analysis, it was found that BET thin films have polycrystalline structure, and the layered-perovskite phase is obtained when the Eu contents exceeds 0.2 (x > 0.2). Also, the ferroelectric characteristics of the BET thin films were found to be dependent on the Eu content. Particularly, the BET films doped with x = 0.75 show better ferroelectric properties (remanent polarization 2Pr = 60.99 C/$cm^2$ and only a little polarization fatigue up to $3.5{\times}10^9$ bipolar switching cycling) than those doped with other Eu contents.