Journal of Sensor Science and Technology (센서학회지)

The Korean Sensors Society (한국센서학회)
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Effect of the hetero-epitaxial ZnO buffer layer for the formation of As-doped ZnO thin films

Hetero-epitaxial ZnO 버퍼층이 As-doped ZnO 박막의 증착조건에 미치는 영향

  • Lee, Hong-Chan (Thin Film Materials Research Center, Korea Institute of Science and Technology) ;
  • Choi, Won-Kook (Thin Film Materials Research Center, Korea Institute of Science and Technology) ;
  • Shim, Kwang-Bo (Department of Ceramic Engineering, Hanyang Univ.) ;
  • Oh, Young-Jei (Thin Film Materials Research Center, Korea Institute of Science and Technology)
  • 이홍찬 (한국과학기술연구원 박막재료연구센터) ;
  • 최원국 (한국과학기술연구원 박막재료연구센터) ;
  • 심광보 (한양대학교 세라믹공학과) ;
  • 오영제 (한국과학기술연구원 박막재료연구센터)
  • Published : 2006.05.31
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Abstract

ZnO thin films prepared by PLD method exhibit an excellent optical property, but may have some problems such as incomplete surface roughness and crystallinity. In this study, undoped ZnO buffer layers were deposited on (0001) sapphire substrates by ultra high vacuum pulse laser deposition (UHV-PLD) and molecular beam epitaxy (MBE) methods, respectively. After post annealing of ZnO buffer layer, undoped ZnO thin films were deposited under different oxygen pressure ($35{\sim}350$ mtorr) conditions. The Arsenic-doped (1, 3 wt%) ZnO thin layers were deposited on the buffer layer of undoped ZnO by UHV-PLD method. The optical property of the ZnO thin films was analyzed by photoluminescence (PL) measurement. The ${\theta}-2{\theta}$ XRD analysis exhibited a strong (002)-peak, which indicates c-axis preferred orientation. Field emission-scanning electron microscope (FE-SEM) revealed that microstructures of the ZnO thin films were varied by oxygen partial pressure, Arsenic doping concentration, and deposition method of the undoped ZnO buffer layer. The denser and smoother films were obtained when employing MBE-buffer layer under lower oxygen partial pressure. It was also found that higher Arsenic concentration gave the enhanced growing of columnar structure of the ZnO thin films.

Keywords

References

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