• Title/Summary/Keyword: $TiO_2$ Thickness

Search Result 672, Processing Time 0.03 seconds

A Study of Photo-electric Efficiency Improvement using Ultrasonic and Thermal Treatment on Photo-electrode of DSC (염료감응형 태양전지 광전극의 초음파 열처리를 통한 광전효율 개선에 관한 연구)

  • Kim, Hee-Je;Kim, Yong-Chul;Choi, Jin-Young;Kim, Ho-Sung;Lee, Dong-Gil;Hong, Ji-Tae
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.5
    • /
    • pp.803-807
    • /
    • 2008
  • A making process of DSC(dye sensitized solar cell) was presented. In general, Photo electrodes of DSC was made by using colloid paste of nano $TiO_2$ and processing of Doctor-blade printing and high temperature sintering for porous structure. These methods lead to cracks on $TiO_2$ surface and ununiform of $TiO_2$ thickness. This phenomenon is one factor that makes low efficiency to cells. After $TiO_2$ printing on TCO glass, a physical vibration was adapted for reducing ununiform of $TiO_2$ thickness. And a thermal treatment at low temperature(under $75^{\circ}C$) was adapted for reducing cracks on $TiO_2$ surface. In this paper, we have designed and manufactured an ultrasonic circuit (100W, frequency and duty variable) and a thermal equipment. Then, we have optimized forcing time, frequency and duty of ultrasonic irradiation and thermal heating for surface treatment of photo-electrode of DSC. In I-V characteristic test of DSC, ultrasonic and thermal treated DSC shows 19% improved its efficiency against monolithic DSC. And it shows stability of light-harvesting from drastically change of light irradiation test.

Super Hydrophilic Properties of SiO2-TiO2 Thin Film Prepared by Sol-Gel Method (졸-겔법에 의한 SiO2-TiO2 박막의 초친수성)

  • Park, Min-Jung;Lee, Kyoung-Seok;Kang, Jong-Bong;Mun, Chong-Soo
    • Korean Journal of Materials Research
    • /
    • v.17 no.3
    • /
    • pp.125-131
    • /
    • 2007
  • [ $TiO_{2}-solution$ ] was aaded in $SiO_{2}-solution$ by various composition. $SiO_{2}-TiO_{2}$ thin films were obtained by the dip-coating method on the $SiO_{2}$ glass substrates, and then heat-treated at various temperature. Nano-size $TiO_{2}$ particles dispersed $SiO_{2}-TiO_{2}$ films showed absorption peak by quantum size effect at short wavelength region $350{\sim}400nm$, which made them good candidates for non-linear optical materials and photo-catalytic materials. The thickness of $SiO_{2}-TiO_{2}$ films were $300{\sim}430nm$. The contact angle of $SiO_{2}-TiO_{2}$ films for water was $5.3{\sim}47.9^{\circ}$, and therefore it is clear that $SiO_{2}-TiO_{2}$ films have super hydrophilic properties and the self-cleaning effects.

Characterization of 0.5 % Ce-doped Ba($Zr_{0.2}Ti_{0.8}$)$O_3$ Thin Films Grown by RF Magnetron Sputtering Method (RF 마그네트론 스퍼터링법으로 성장시킨 0.5 % Ce-doped Ba($Zr_{0.2}Ti_{0.8}$)$O_3$(BCZT) 박막의 특성분석)

  • 최원석;박용섭;이준신;홍병유
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.07a
    • /
    • pp.301-304
    • /
    • 2002
  • We investigated the structural and electrical properties of Ce-doped Ba($Zr_{0.2}Ti_{0.8}$)$O_3$(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 m (RMS at $500^{\circ}C$, Ar:6 scrim, $O_2$:6 sccm). We have found that annealing procedure after top electrode deposit can reduce the dissipation factor.

  • PDF

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

  • 최원석;박용섭;이준신;홍병유
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.5
    • /
    • pp.361-364
    • /
    • 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.

Characteristics of Nano-Size Au Fine Particles Doped TiO2 Thin Films by Sol-Gel Method (졸-겔법에 의한 나노크기 Au 미립자 분산 TiO2 박막의 특성)

  • Park, Min-Jung;Koo, Se-Na;Lee, Kyoung-Seok;Mun, Chong-Soo
    • Journal of the Korean Ceramic Society
    • /
    • v.43 no.2 s.285
    • /
    • pp.114-120
    • /
    • 2006
  • Nano-size Au particle doped $TiO_2$ films were prepared with $Ti(OC_3H_7^i)_4$, polyvinylpyrrolidone(PVP), $HAuCl_4$ and $C_3H_7OH$ etc. by sol-gel method. $TiO_2$ gel films were obtained by the dip-coating method on the $SiO_2$ glass substrates, and then heat-treated at $700^{\circ}C$ for 10 min. The thickness of $TiO_2$ films were $0.7\~1.8\;{\mu}m$. It was found that the thickness of films prepared from PVP containing solution was about $2\~8$ times higher values than that of thin films without PVP. The size of Au particles doped in the films were about $350\~750\;nm$. Nano-size Au particle dispersed $TiO_2$ films showed high absorption peak at visible region 450nm, which made them good candidates for non-linear optical materials and photo-catalytic materials. The contact angle of $TiO_2$ film for water was $12.5^{\circ}$, and therefore it is clear that $TiO_2$ films have very high hydrophilic properties and the self-cleaning effects.

Development of Multi-layered TiO2/Al, Cr/TiO2 Pearl Pigment Processed by DC and RF Magnetron Sputtering Process (DC와 RF Magnetron Sputtering 공법을 이용한 다층 TiO2/Al, Cr/TiO2 진주안료 개발)

  • Jeong Jae-Il;Lee Jeong-Hun;Jang Gun-Eik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.19 no.8
    • /
    • pp.764-768
    • /
    • 2006
  • For the possible application of pearl pigment, multi-layered $TiO_2/Al,\;Cr/TiO_2$ thin film were deposited on $SiO_2$ substrate by using sputtering method, $TiO_2$ and Al or Cr was selected as a possible high and low refraction material at the film interface respectively. Optical properties including color effect were systematically studied in terms of different film thickness and film layers by using spectrometer. In order to expect the experimental results, the simulation program, the Essential Macleod Program(EMP) was adopted and compared with the experimental data. The film consisting of $TiO_2/Al,\;Cr/TiO_2$ layers shows a wavelength range of $430{\sim}760nm$, typically color ranges between bluish purple and red. It was confirmed that this experimental result was quite well consistent with the experimental one.

Photo Catalytic Ability of Acicular Shaped TiO$_{2}$ Rutile Powder in Aqueous Metal-EDTA Solutions

  • Kim, Sun-Jae;chang-Joo choi;Park, Soon-Dong;Hwang, Jong-Sun;Han, Byung-Sung
    • Transactions on Electrical and Electronic Materials
    • /
    • v.2 no.2
    • /
    • pp.37-41
    • /
    • 2001
  • Photo catalytic characteristics of nano-sized TiO$_2$ powder with rutile phase produced using homogeneous precipitation process at low temperatures (HPPLT) were compared with those of commercial P-25 powder by Degussa Co. The TiO$_2$ powder by HPPLT showed very higher photoactivity in the removal rate, showing lower pH values in the solution, than the P-25 powder when eliminating metal ions such as Pb and Cu from aqueous metal-EDTA solutions. This can be inferred the more rapid photo-oxidation or -reduction of metal ions from the aqueous solution, together with relatively higher efficiencies in the use of electron-hole pair formed on the surface of TiO$_2$ particle, under UV light irradiation. Also, in the view of the TiO$_2$ particle morphology, compared to the well-dispersed spherical P-25 particle, the agglomerated TiO$_2$ particle by HPPL T consists of acicular typed primary particle with the thickness ranged of 3∼7 nm, which would be more effective to the photocatalytic reactions without electron-hole recombination on the surface of the TiO$_2$ particle under the UV light irradiation. It is, therefore, thought that the higher photo activity of the rutile TiO$_2$ powder by HPPLT in the aqueous solutions resulted from having its higher specific surface area as well as acicular shape primary particle with very thin thickness.

  • PDF

A Study on the Operational Variables of the UV-TiO$_2$ Based Photocatalytic Air Cleaning System (UV-TiO$_2$ 광촉매 기반의 공기 정화 시스템의 운전조건에 대한 연구)

  • Han, Chang-Seok;Chang, Hyuk-Sang
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.30 no.3
    • /
    • pp.293-301
    • /
    • 2008
  • A study on the operational variables of the UV-TiO$_2$ based photocatalytic air cleaning system was tried. In this study, to examine effects as various air cleaning system conditions, a duct-type reactor was made, and TiO$_2$ was immobilized on a stainless mesh. Benzene was chosen as a target compound. Removal experiments for benzene were done under different initial benzene concentration, air velocity, TiO$_2$ loading, area coated TiO$_2$ as the same TiO$_2$ loading, and UV light intensity conditions. During the experiments, relative humidity was 55%, and reactor temperature was 45$^{\circ}C$. As a result, the photocatalytic degradation of benzene decreased as the inlet concentration increased. But the photocatalytic degradation increased as the concentration boundary layer thickness, amount of TiO$_2$, area coated TiO$_2$ as the same amount of TiO$_2$, and UV light intensity increased. Based on results of current study, they can be applied to the design of air cleaning system over low level VOCs in the indoor air.

Brazing characteristics of $ZrO_2$ and Ti-6Al-4V brazed joints with increasing temperature (브레이징 온도 변화에 따른 $ZrO_2$와 Ti-6Al-4V의 접합 특성)

  • Kee, Se-Ho;Park, Sang-Yoon;Heo, Young-Ku;Jung, Jae-Pil;Kim, Won-Joong
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.50 no.3
    • /
    • pp.169-175
    • /
    • 2012
  • Purpose: In this study, brazing characteristics of $ZrO_2$ and Ti-6Al-4V brazed joints with increasing temperature were investigated. Materials and methods: The sample size of the $ZrO_2$ was $3mm{\times}3mm{\times}3mm$ (thickness), and Ti-6Al-4V was $10mm(diameter){\times}5mm(thickness)$. The filler metal consisted of Ag-Cu-Sn-Ti was prepared in powder form. The brazing sample was heated in a vacuum furnace under $5{\times}10^{-6}$ torr atmosphere, while the brazing temperature was changed from 700 to $800^{\circ}C$ for 30 min. Results: The experimental results shows that brazed joint of $ZrO_2$ and Ti-6Al-4V occurred at $700-800^{\circ}C$. Brazed joint consisted of Ag-rich matrix and Cu-rich phase. A Cu-Ti intermetallic compounds and a Ti-Sn-Cu-Ag alloy were produced along the Ti-6Al-4V bonded interface. Thickness of the reacted layer along the Ti-6Al-4V bonded interface was increased with brazing temperature. Defect ratios of $ZrO_2$ and Ti-6Al-4V bonded interfaces decreased with brazing temperature. Conclusion: Thickness and defect ratio of brazed joints were decreased with increasing temperature. Zirconia was not wetting with filler metal, because the reaction between $ZrO_2$ and Ti did not occur enough.