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, Takayuki Sota, M. Kawasaki, S. F. Chichibu

    Research output: Contribution to journalArticle

    24 Citations (Scopus)

    Abstract

    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.

    Original languageEnglish
    Pages (from-to)2841-2845
    Number of pages5
    JournalPhysica Status Solidi (A) Applied Research
    Volume201
    Issue number12
    DOIs
    Publication statusPublished - 2004 Sep

    Fingerprint

    Positron annihilation
    Epilayers
    Defect density
    positron annihilation
    Photoluminescence
    Point defects
    photoluminescence
    life (durability)
    point defects
    Vacancies
    defects
    Defects
    Growth temperature
    Positrons
    Substrates
    positrons
    Scattering
    room temperature
    scattering
    Temperature

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Electronic, Optical and Magnetic Materials

    Cite this

    Direct comparison of photoluminescence lifetime and defect densities in ZnO epilayers studied by time-resolved photoluminescence and slow positron annihilation techniques. / Koida, T.; Uedono, A.; Tsukazaki, A.; Sota, Takayuki; Kawasaki, M.; Chichibu, S. F.

    In: Physica Status Solidi (A) Applied Research, Vol. 201, No. 12, 09.2004, p. 2841-2845.

    Research output: Contribution to journalArticle

    @article{bc3c7913d7194d5dac282c2c7cf4dc83,
    title = "Direct comparison of photoluminescence lifetime and defect densities in ZnO epilayers studied by time-resolved photoluminescence and slow positron annihilation techniques",
    abstract = "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.",
    author = "T. Koida and A. Uedono and A. Tsukazaki and Takayuki Sota and M. Kawasaki and Chichibu, {S. F.}",
    year = "2004",
    month = "9",
    doi = "10.1002/pssa.200405035",
    language = "English",
    volume = "201",
    pages = "2841--2845",
    journal = "Physica Status Solidi (A) Applied Research",
    issn = "0031-8965",
    publisher = "Wiley-VCH Verlag",
    number = "12",

    }

    TY - JOUR

    T1 - Direct comparison of photoluminescence lifetime and defect densities in ZnO epilayers studied by time-resolved photoluminescence and slow positron annihilation techniques

    AU - Koida, T.

    AU - Uedono, A.

    AU - Tsukazaki, A.

    AU - Sota, Takayuki

    AU - Kawasaki, M.

    AU - Chichibu, S. F.

    PY - 2004/9

    Y1 - 2004/9

    N2 - 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.

    AB - 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.

    UR - http://www.scopus.com/inward/record.url?scp=6344258317&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=6344258317&partnerID=8YFLogxK

    U2 - 10.1002/pssa.200405035

    DO - 10.1002/pssa.200405035

    M3 - Article

    AN - SCOPUS:6344258317

    VL - 201

    SP - 2841

    EP - 2845

    JO - Physica Status Solidi (A) Applied Research

    JF - Physica Status Solidi (A) Applied Research

    SN - 0031-8965

    IS - 12

    ER -