Identifying threading dislocation types in ammonothermally grown bulk α-GaN by confocal Raman 3-D imaging of volumetric stress distribution

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date
2018-07-25
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Language
en
Pages
8
47-54
Series
JOURNAL OF CRYSTAL GROWTH, Volume 499
Abstract
This study demonstrates all-optical Raman scattering study of dislocations in ammonothermally grown α-GaN crystal and identifies an edge a-type threading dislocation (TD) using a confocal Raman 3-D imaging technique. These findings make possible the characterization of volumetric stress field and low TD density distributions over a large area on bulk α-GaN single crystal. The dislocation type effects on Raman shift are also discussed in detail (in order to identify the edge a-type and mixed a+c-type TDs, and theorize the invisibility of the screw c-type TDs). Authors are not aware of any previous reports using the confocal Raman 3-D imaging to identify the edge a-type and mixed a+c-type TDs.
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Keywords
Confocal Raman spectroscopy, Three-dimensional (3-D) imaging, Stress distribution, Dislocation types, Bulk hexagonal GaN, Ammonothermal crystal growth
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Citation
Holmi , J , Bairamov , B H , Suihkonen , S & Lipsanen , H 2018 , ' Identifying threading dislocation types in ammonothermally grown bulk α-GaN by confocal Raman 3-D imaging of volumetric stress distribution ' , Journal of Crystal Growth , vol. 499 , pp. 47-54 . https://doi.org/10.1016/j.jcrysgro.2018.07.024