• 한국재료학회지
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• 제31권1호
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• pp.8-15
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• 2021

Transparent, photocatalytic, and self-cleaning TiO2 thin film is developed by TiO2 sol-gel coating on glass and polycarbonate (PC) substrates. Acetyl acetone (AcAc) suppresses the precipitation of TiO2 by forming a yellowish (complex) transparent sol-gel. XPS analysis confirms the presence of Ti2p and O1s in the thin films on glass and PC substrates. The TiO2-sol is prepared by stabilizing titanium (IV) isopropoxide (TTIP) with diethylamine and methyl alcohol. The addition of AcAcsilane coupling solution to the TiO2-sol instantaneously turns to yellowish color owing to the complexing of titanium with AcAc. The AcAc solution substantially improves the photocatalytic property of the TiO2 coating layer in MB solutions. The coated TiO2 film exhibits super hydrophilicity without and with light irradiation. The TiO2 thin film stabilized by adding 8.7 wt% AcAc shows the highest photo-degradation for methylene blue (MB) solution under UV light irradiation. Also, the optimum photocatalytic activity is obtained for the 8.7 wt% AcAc-stabilized TiO2 coating layer calcined at 450 ℃. The thin-films on glass exhibit fast self-cleaning from oleic acid contamination within 45 min of UV-light irradiation. The appropriate curing time at 140 ℃ improves the anti-fogging and thermal stability of the TiO2 film coated on PC substrate. The watermark-free PC substrate is particularly beneficial to combat fogging problems of transparent substrates.

• 한국전기전자재료학회논문지
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• 제23권9호
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• pp.681-684
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• 2010

The $TiO_2$/ZnS/Ag/ZnS/$TiO_2$ multilayered structure for the transparent electrodes in plasma display panel was designed by essential macleod program (EMP) and the multilayered film was deposited on a glass substrate by direct-current (DC)/radio-frequency (RF) magnetron sputtering system. During film deposition process, the Ag layer in $TiO_2$/Ag/$TiO_2$ structure became oxidized and the filter characteristic was degraded easily. In this study, ZnS layer was adopted as a diffusion blocking layer between $TiO_2$ and Ag to prevent the oxidation of Ag layer efficiently in $TiO_2$/ZnS/Ag/ZnS/$TiO_2$ structure. Based on the AES depth profiling analysis, the Ag layer was effectively protected by the ZnS layer as compared with the $TiO_2$/Ag/$TiO_2$ multilayered films without ZnS as an antioxidant layer. The 3 times stacked $TiO_2$/ZnS/Ag/ZnS/$TiO_2$ films have low sheet resistance of $1.22{\Omega}/{\square}$ and luminous transmittance was as high as 62% in the visible ranges.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.511-511
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• 2007

Low-emissivity (low-e) coatings with visible transparency have attracted increased interest m reducing heat radiation loss through window panes from ecological and sustainable aspects. $TiO_2$-silver transparent thin films for low-e have good properties for UV and IR blocking as well as photocatalyst compared to that with commercial UV blocking films such as fluorine doped oxide (FTO), antimony doped tin oxide (ATO), etc. In this study, transparent $TiO_2$-silver thin films were prepared by successive ink-jet printing of commercial nano silver and $TiO_2$ sol. The $TiO_2$ sol, as ink for ink-jet printing, were synthesized by hydrothermal process in the autoclave externally pressurized with $N_2$ gas of 200 bar at $120^{\circ}C$ for 10 hrs. The synthesized $TiO_2$ sols were all formed with brookite phase and their particle size was several to 30 nm. At first nano sized silver sol was coated on glass substrate, after that $TiO_2$ sol was coated by ink-jet printing. With increasing coating thickness of $TiO_2$-silver multilayer by repeated ink-jet coating, the absorbance of UV region (under 400nm) and IR region (over 700nm) also increase reasonably, compared to that with commercial UV blocking films.

• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.107-109
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• 1998

The $SnO_2$, Sn-doped $In_2O+3\; and \;Ce-doped\; TiO_2$ films have been prepared by RF sputtering method, and their opto-electrochemical properties were investigated in view of the applicability as counter electrodes in the electrochromic window system. These oxide films could reversibly intercalate $Li^+$ ions owing to the nanocrystalline texture, but remained colorless and transparent. The high transmittance of the lithiated films could be attributed to the prevalence of the $Sn^{4+}/Sn^{2+}\; and\; Ce^{4+}/Ce^{3+}$ redox couples having 5s and 6s character conduction bands, respectively. For the Ce-doped $TiO_2$ film, $(TiO_2)_{1-x}(CeO_2)_x$, an optimized electrochemical reversibility was found in the film with the composition of x = 0.1.

• 열처리공학회지
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• 제28권6호
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• pp.296-299
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• 2015

$In_2O_3/Ti$ bi-layered films were deposited on glass substrate at room temperature with radio frequency (RF) and direct current (DC) magnetron sputtering to consider the effect of Ti buffer layer on the electrical and optical properties. In a comparison of figure of merit, $In_2O_3$ 90 nm/Ti 10 nm thin films show the higher opto-electrical performance of $3.0{\times}10^{-4}{\Omega}^{-1}$ than that of the $In_2O_3$ single layer films ($2.6{\times}10^{-4}{\Omega}^{-1}$). From the observed results, it is supposed that the $In_2O_3\;90nm/TiO_2$ 10 nm bi-layered films may be an alternative candidate for transparent electrode in a transparent thin film transistor device.

• 한국표면공학회지
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• 제40권4호
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• pp.190-196
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• 2007

Dye sensitized solar cells(DSSC) are the most promising future energy resource due to their high energy efficiency, low production cost, and simple manufacturing process. But one problem in DSSC is short life time compared to silicon solar cells. This problem occurred from photocatalytic degradation of dye material by nanometer sized $TiO_2$ particles. To prevent dye degradation as well as to increase its life time, the transparent coating film is needed for UV blocking. In this study, we synthesized nanometer sized $TiO_2$ particles in sols by increasing its internal pressure up to 200 bar in autoclave at $120^{\circ}C$ for 10 hrs. The synthesized $TiO_2$ sols were all formed with brookite phase and their particle size was several nm to 30 nm. Synthesized $TiO_2$ sols were coated on the backside of fluorine doped tin oxide(FTO) glass by ink jet printing method. With increasing coating thickness by repeated ink jet coating, the absorbance of UV region (under 400 nm) also increases reasonably. Decomposition test of titania powders dispersed in 0.1 mM amaranth solution covered with $TiO_2$ coating glass shows more stable dye properties under UV irradiation, compared to that with as-received FTO glass.

• 한국광학회지
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• 제13권4호
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• pp.363-369
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• 2002

디스플레이 기기에 사용할 수 있는 전도성 투과필터를 저방출(low-emissivity) 코팅인 [유전체|Ag|유전체] 구조를 이용하여 설계하였다. [$TiO_{2}$|Ti|Ag|$TiO_{2}$] 구조를 반복하고 어드미턴스 방법을 이용하여 가시광선 영역의 투과율을 높이고, 근적외선의 투과율은 낮게 하였다. 전도성 투과필터를 radio frequency(RF) 마그네트론 스퍼터링 방법으로 증착하고 설계한 스펙트럼과 비교하였으며, 필터의 광학적, 구조적, 전기적 특성들을 조사하였다. Ag 박막의 두께는 전기전도성을 높이기 위해 13㎚ 이상으로 증착하고, $TiO_{2}$박막은 가시광선 영역에서 투과율이 최대가 되는 24㎚로 증착하였다. 또한 Ag 박막의 산화를 막기 위해 매우 얇은 Ti 산화방지막을 증착하였으며, 다층구조로 갈수록 산화방지막의 두께를 더 두껍게 증착해야 하는 것을 확인하였다. 최종적으로 [$TiO_{2}$|Ti|Ag|$TiO_{2}$] 기본구조를 3번 반복하여 증착한 필터는 근적외선 차단 효과가 우수하고, 전자파 장해(electromagnetic interference; EMI)를 효과적으로 방지할 수 있는 2Ω/□ 이하의 낮은 면저항을 보였다.

• 한국재료학회지
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• 제21권7호
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• pp.371-376
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• 2011

We report on the effects of $TiO_2$ doping power on the characteristics of multicomponent $TiO_2$-ITO (TITO) electrodes prepared by a multi-target sputtering system with tilted cathode guns. Both as-deposited and annealed TITO electrodes showed linearly increased sheet resistance and resistivity with increasing $TiO_2$ doping power. However, the TITO electrodes exhibited a fairly high optical transmittance regardless of the $TiO_2$ doping power due to the high transparency of the $TiO_2$. Although the annealed TITO showed much lower sheet resistance and resistivity relative to the as-deposited samples, the electrical properties of the annealed samples exhibited similar dependence on the $TiO_2$ power to the as-deposited samples. In addition, it was found that doping of an anatase $TiO_2$ in the ITO electrode prevented the preferred (222) orientation of the TITO electrodes. Although the TITO electrode showed higher sheet resistance and resistivity than that of the pure ITO electrode, it offers a very smooth surface and usage of a low-cost Ti element. It is thus considered a promising multicomponent transparent conducting electrode for cost-efficient flat panel displays and photovoltatics.

• 한국진공학회지
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• 제5권2호
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• pp.147-155
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• 1996

Optical properties of $TiO_2/M/Ag/M/TiO_2$ films have been changed with the diffusion barrier metal M. Optimum opticla properties of $TiO_2/M/Ag/M/TiO_2$ as the transparent heat mirror film, could be obtained with Ti among diffusion barrier metals of Ti, Cu, Zr and Al. $TiO_2/M/Ag/M/TiO_2$ film, which was fabricated by sputtering of 18 nm-thick $TiO_2$ and Ag, and 4nm-thick Ti, showed maximum transimittance of 89% at visible wavelength and infrared reflectance of 97% at wavelength of 3000 nm. Optical properties of this film was not degraded by Xenon-sunshine weather test for 240 hours. For specimens with barrier layers of Cu, Zr, and Al, degradation of optical properties by weather test was increased in a sequence of films with Cu, Zr, and Al barrier layers.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.1-6
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• 2017

태양전지의 셀을 보호하기 위한 커버 글라스에는 반사방지 코팅 및 셀프클리닝과 같은 기능성 코팅이 적용되어왔다. 일반적으로 메조포러스 실리카를 이용한 반사방지 코팅은 빛의 투과를 증가시키며, $TiO_2$ 광촉매 필름은 셀프클리닝 코팅에 적용되어왔다. 본 연구에서는 $SiO_2/TiO_2$ 박막 코팅에 의한 투명 발수 반사방지 및 셀프클리닝 코팅을 sol-gel 공정과 dip-coating 공정으로 글라스 기판 위에 제조하였다. 기능성 코팅의 표면형상은 전계방출 주사전자현미경과 원자힘 현미경으로 분석하였고, 광학적 특성은 UV-visible 분광광도계로 분석하였다. 필름의 발수특성은 접촉각 측정으로 확인하였다. 그 결과 $TiO_2$ 필름은 기판인 슬라이드 글라스와 비슷한 수준의 높은 광 투과율을 나타내었다. 일반적으로 $TiO_2$ 나노입자는 필름에서 반사를 증가시키며, 결과적으로 투과율의 저하를 가져온다. 하지만 본 연구의 $SiO_2/TiO_2$ 박막으로 이루어진 기능성 코팅은 $110^{\circ}$의 접촉각을 나타내었으며, 파장 550 nm에서 기판인 슬라이드 글라스의 투과율보다 2.0% 증가한 93.5%의 광 투과율 특성을 나타내었다.