TY - JOUR
T1 - Effect of Zn and Te beam intensity upon the film quality of ZnTe layers on severely lattice mismatched sapphire substrates by molecular beam epitaxy
AU - Nakasu, Taizo
AU - Sun, W.
AU - Kobayashi, M.
AU - Asahi, T.
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017/6/15
Y1 - 2017/6/15
N2 - Zinc telluride layers were grown on highly-lattice-mismatched sapphire substrates by molecular beam epitaxy, and their crystallographic properties were studied by means of X-ray diffraction pole figures. The crystal quality of the ZnTe thin film was further studied by scanning electron microscopy, X-ray rocking curves and low-temperature photoluminescence measurements. These methods show that high-crystallinity (111)-oriented single domain ZnTe layers with the flat surface and good optical properties are realized when the beam intensity ratio of Zn and Te beams is adjusted. The migration of Zn and Te was inhibited by excess surface material and cracks were appeared. In particular, excess Te inhibited the formation of a high-crystallinity ZnTe film. The optical properties of the ZnTe layer revealed that the exciton-related features were dominant, and therefore the film quality was reasonably high even though the lattice constants and the crystal structures were severely mismatched.
AB - Zinc telluride layers were grown on highly-lattice-mismatched sapphire substrates by molecular beam epitaxy, and their crystallographic properties were studied by means of X-ray diffraction pole figures. The crystal quality of the ZnTe thin film was further studied by scanning electron microscopy, X-ray rocking curves and low-temperature photoluminescence measurements. These methods show that high-crystallinity (111)-oriented single domain ZnTe layers with the flat surface and good optical properties are realized when the beam intensity ratio of Zn and Te beams is adjusted. The migration of Zn and Te was inhibited by excess surface material and cracks were appeared. In particular, excess Te inhibited the formation of a high-crystallinity ZnTe film. The optical properties of the ZnTe layer revealed that the exciton-related features were dominant, and therefore the film quality was reasonably high even though the lattice constants and the crystal structures were severely mismatched.
KW - A1. X-ray diffraction
KW - A3. Molecular beam epitaxy
KW - B1. Sapphire
KW - B1. Zinc compounds
KW - B2. Semiconducting II-VI materials
KW - B3. Heterojunction semiconductor devices
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U2 - 10.1016/j.jcrysgro.2016.11.035
DO - 10.1016/j.jcrysgro.2016.11.035
M3 - Article
AN - SCOPUS:85006722212
VL - 468
SP - 635
EP - 637
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
ER -