Direct comparison of photoluminescence lifetime and defect densities in ZnO epilayers studied by time-resolved photoluminescence and slow positron annihilation techniques

T. Koida, A. Uedono, A. Tsukazaki, T. Sota, M. Kawasaki, S. F. Chichibu

研究成果: Article査読

25 被引用数 (Scopus)

抄録

The roles of point defects and defect complexes governing nonradiative processes in ZnO epilayers were studied using time-resolved photoluminescence (PL) and slow positron annihilation measurements. The density or size of Zn vacancies (VZn) decreased and the nonradiative PL lifetime (τnr) increased with higher growth temperature for epilayers grown on a ScAlMgO4 substrate. Accordingly, the steady-state free excitonic PL intensity increased with increase in τnr, at room temperature. The use of a homoepitaxial substrate further decreased the V Zn concentration. However, no perfect relation between τnr and the density or size of VZn, or other positron scattering centers was found. The results indicated that nonradiative recombination processes are governed not solely by single point defects, but by certain defect species introduced by the presence of VZn such as vacancy complexes.

本文言語English
ページ(範囲)2841-2845
ページ数5
ジャーナルPhysica Status Solidi (A) Applied Research
201
12
DOI
出版ステータスPublished - 2004 9 1

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 凝縮系物理学

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