TY - JOUR
T1 - Optimization of the growth conditions for molecular beam epitaxy of Mg xZn1-xO (0 < x < 0:12) films on Zn-polar ZnO substrates
AU - Yuji, Hiroyuki
AU - Nakahara, Ken
AU - Tamura, Kentaro
AU - Akasaka, Shunsuke
AU - Nishimoto, Yoshio
AU - Takamizu, Daiju
AU - Onuma, Takeyoshi
AU - Chichibu, Shigefusa F.
AU - Tsukazaki, Atsushi
AU - Ohtomo, Akira
AU - Kawasaki, Masashi
PY - 2010/7
Y1 - 2010/7
N2 - We report on optimization of the growth conditions for Mg xZn1-xO (x = 0; 0:04; 0:05; 0:12) thin films grown on c-plane Zn-polar ZnO single crystal substrates by using plasma-assisted molecular beam epitaxy (PAMBE). A normal vector to the ZnO substrate surfaces was angled at 0:5 ± 0:1° off from the [0001] c-axis toward the [11̄100] direction, leading to a stable step-and-terrace structure. A growth temperature (Tg) higher than 800 °C led to the ZnO films presenting the first excited state luminescence of A-free excitons in photoluminescence (PL) spectra at 12 K. A Tg higher than 800 °C enhanced optical attributes of a MgxZn1-xO film. The longest PL lifetime of fast-decay components reached 3.5 ns in time-resolved PL measurement for an Mg0.12Zn0.88O film grown at 900 °C, indicating a concentration of nonradiative recombination centers is substantially eliminated compared to the previously reported PL lifetime of 60 ps for an Mg0.11Zn0.89O film grown by pulsed laser deposition.
AB - We report on optimization of the growth conditions for Mg xZn1-xO (x = 0; 0:04; 0:05; 0:12) thin films grown on c-plane Zn-polar ZnO single crystal substrates by using plasma-assisted molecular beam epitaxy (PAMBE). A normal vector to the ZnO substrate surfaces was angled at 0:5 ± 0:1° off from the [0001] c-axis toward the [11̄100] direction, leading to a stable step-and-terrace structure. A growth temperature (Tg) higher than 800 °C led to the ZnO films presenting the first excited state luminescence of A-free excitons in photoluminescence (PL) spectra at 12 K. A Tg higher than 800 °C enhanced optical attributes of a MgxZn1-xO film. The longest PL lifetime of fast-decay components reached 3.5 ns in time-resolved PL measurement for an Mg0.12Zn0.88O film grown at 900 °C, indicating a concentration of nonradiative recombination centers is substantially eliminated compared to the previously reported PL lifetime of 60 ps for an Mg0.11Zn0.89O film grown by pulsed laser deposition.
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U2 - 10.1143/JJAP.49.071104
DO - 10.1143/JJAP.49.071104
M3 - Article
AN - SCOPUS:77956536833
VL - 49
SP - 711041
EP - 711045
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 7 PART 1
ER -