• Title/Summary/Keyword: Reflectance and transmittance

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Optical properties and applications of $TiO_2$ films prepared by ion beam sputtering (이온빔 스퍼터링으로 증착한 $TiO_2$박막의 광학적 특성 및 응용)

  • 이정환;조준식;김동환;고석근
    • Journal of the Korean Vacuum Society
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    • v.11 no.3
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    • pp.176-182
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    • 2002
  • Amorphous $TiO_2$ thin films were deposited on glass substrates by ion beam sputtering in which the ratio of $O_2$/Ar gas used as discharged gas was varied from 0 to 2. After optical and microstructure properties and chemical composition of thin films was analyzed, antireflection coating layers were fabricated with $SiO_2$/$TiO_2$ multi-layers. Thin films deposition was performed at room temperature and ion beam voltage and ion current density for sputtering of target were fixed at 1.2 kV and 200 $\mu\textrm{A}/\textrm{cm}^2$, respectively. Refractive indexs of the deposited $TiO_2$films were 2.40-2.45 at a wavelength of 633 nm. $TiO_2$films had high transmission and stoichiometry when ratio of $O_2$/Ar was 1. Rms roughness of deposited $TiO_2$ film was below 7 $\AA$. In excessive $O_2$ environments, however Rms roughness increased over 50 $\AA$. Transmittance decreased by scattering of rough surface. Reflectance of $SiO_2$/$TiO_2$multi-layers was below 1% in visible light.

Selective Transmission Properties of Al-Ti Based Oxide Thin Films (Al-Ti계 산화물 박막의 조성에 따른 선택적 투과 특성)

  • Bang, Ki Su;Jeong, So Un;Lim, Jung Wook;Lee, Seung-Yun
    • Journal of the Korean Vacuum Society
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    • v.22 no.1
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    • pp.13-19
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    • 2013
  • It is expected that progress in building-integrated photovoltaic (BIPV) systems, improving the functionality and design of buildings, will be accelerated in the coming years. While the dye sensitized solar cell is considered one of the most important technologies in the BIPV field, the transparent silicon based thin film solar cell fabricated by thin film processes has drawn attention as a novel alternative. When the selective transmitting layer is applied to the solar cell, the conversion efficiency is improved due to the re-reflection of infrared light into an absorber layer with the transmission of visible light through the solar cell. In this work, we prepared Al-Ti based oxide thin films using cost-effective sputter deposition and examined their selective transmitting characteristics with various compositions. The transmittance and reflectance of the Al-Ti based oxide thin film changed with the variation of its composition, and the selective transmitting property was observed in the sample with the 25 nm-thick AlTiO layer. It is considered that the realization of transparent solar cells and the improvement of their conversion efficiency can be achieved by introducing the Al-Ti based selective transmitting layer.