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Takafumi Yao

Researcher at Tohoku University

Publications -  591
Citations -  14672

Takafumi Yao is an academic researcher from Tohoku University. The author has contributed to research in topics: Molecular beam epitaxy & Photoluminescence. The author has an hindex of 49, co-authored 591 publications receiving 14287 citations. Previous affiliations of Takafumi Yao include National Institute of Advanced Industrial Science and Technology.

Papers
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Lattice Deformation in a-Plane ZnO Films Grown on r-Plane Al2O3 Substrates Grown by Plasma-Assisted Molecular-Beam Epitaxy

Seok-Kyu Han, +5 more
- 20 Jul 2012 - 
TL;DR: In this paper, the lattice deformation of a-ZnO films on r-plane Al2O3 substrates, grown by plasma assisted molecular-beam epitaxy (PAMBE), is strongly dependent on growth temperature.
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Stress dependence on N/Ga ratio in GaN epitaxial films grown on ZnO substrates

Tsutomu Minegishi, +5 more
- 01 Nov 2004 - 
TL;DR: In this article, the authors theoretically calculated the thermal stress caused by the difference of thermal expansion coefficients between GaN and ZnO, and evaluated the changes of stress and critical thickness for HT and LT GaN buffer grown under Ga-rich and N-rich conditions.
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Preparation and characterization of room-temperature ferromagnetism GaMnN based on ion implantation

Jiqing Wang, +10 more
- 01 Oct 2003 - 
TL;DR: In this article, the fabrication of GaMnN ferromagnetic semiconductor on GaN substrate by high-dose Mn ion implantation was reported and the structural and optical properties for Mn+-implanted GaN material were studied by X-ray diffraction, Raman scattering and photoluminescence.
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Photoluminescence of dislocations in plastically deformed GaN

Ichiro Yonenaga, +4 more
- 01 Apr 2006 - 
TL;DR: In this paper, photoluminescence (PL) studies at 11 K showed that the near band edge (3.48 eV) luminescence intensity decreased drastically in the deformed GaN, attributed to the introduction of a high density of non-radiative recombination centers during plastic deformation.
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Investigation of the luminescence properties of ZnO tetrapods and clusters grown on Si substrates

Mina Jung, +7 more
- 01 Mar 2006 - 
TL;DR: In this article, the variation of structural and optical properties of ZnO nanostructures was investigated using Zn powder without catalyst, and the substrate temperature was controlled from 450 to 600 Â c. The results showed that strong luminescence, UV emission at 3.21 Â eV and green emission at 2.5 Ã eV, were observed at room temperature.