Energy-dispersive x-ray imaging of an InGaN/GaN bilayer on sapphire

K. P. O'Donnell; P. G. Middleton; C. Trager-Cowan; C. Young; S. C. Bayliss; I. Fletcher; W. Van der Stricht; I. Moerman; P. Demeester

doi:10.1063/1.122742

Energy-dispersive x-ray imaging of an InGaN/GaN bilayer on sapphire

K. P. O'Donnell, P. G. Middleton, C. Trager-Cowan, C. Young, S. C. Bayliss, I. Fletcher, W. Van der Stricht, I. Moerman, P. Demeester

Physics

Research output: Contribution to journal › Article › peer-review

8 Citations (Scopus)

Abstract

In this letter we discuss the potential and the limitations of quantitative characterization of the distribution of In and Ga atoms in III-N mixed alloys using energy dispersive x-ray (EDX) analysis. Spatial fluctuations of the indium content in an InGaN epilayer are found to correspond to changes in luminescence efficiency. Large hexagonal pyramids, which appear sparsely in such layers, appear to be relatively deficient in indium. Monte Carlo simulations, used to profile the GaK_a x-ray fluorescence, highlight several limitations of the EDX technique in this context, but confirm our interpretation of the data. Finally, we identify differential growth rates as a possible explanation for the concentration/efficiency variations in InGaN layers.

Original language	English
Pages (from-to)	3273-3275
Number of pages	3
Journal	Applied Physics Letters
Volume	73
Issue number	22
DOIs	https://doi.org/10.1063/1.122742
Publication status	Published - 1 Nov 1998

Keywords

InGaN layers
x-ray fluorescence
sapphire

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10.1063/1.122742

Cite this

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title = "Energy-dispersive x-ray imaging of an InGaN/GaN bilayer on sapphire",

abstract = "In this letter we discuss the potential and the limitations of quantitative characterization of the distribution of In and Ga atoms in III-N mixed alloys using energy dispersive x-ray (EDX) analysis. Spatial fluctuations of the indium content in an InGaN epilayer are found to correspond to changes in luminescence efficiency. Large hexagonal pyramids, which appear sparsely in such layers, appear to be relatively deficient in indium. Monte Carlo simulations, used to profile the GaKa x-ray fluorescence, highlight several limitations of the EDX technique in this context, but confirm our interpretation of the data. Finally, we identify differential growth rates as a possible explanation for the concentration/efficiency variations in InGaN layers.",

keywords = "InGaN layers, x-ray fluorescence, sapphire",

author = "O'Donnell, {K. P.} and Middleton, {P. G.} and C. Trager-Cowan and C. Young and Bayliss, {S. C.} and I. Fletcher and {Van der Stricht}, W. and I. Moerman and P. Demeester",

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doi = "10.1063/1.122742",

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T1 - Energy-dispersive x-ray imaging of an InGaN/GaN bilayer on sapphire

AU - O'Donnell, K. P.

AU - Middleton, P. G.

AU - Trager-Cowan, C.

AU - Young, C.

AU - Bayliss, S. C.

AU - Fletcher, I.

AU - Van der Stricht, W.

AU - Moerman, I.

AU - Demeester, P.

PY - 1998/11/1

Y1 - 1998/11/1

N2 - In this letter we discuss the potential and the limitations of quantitative characterization of the distribution of In and Ga atoms in III-N mixed alloys using energy dispersive x-ray (EDX) analysis. Spatial fluctuations of the indium content in an InGaN epilayer are found to correspond to changes in luminescence efficiency. Large hexagonal pyramids, which appear sparsely in such layers, appear to be relatively deficient in indium. Monte Carlo simulations, used to profile the GaKa x-ray fluorescence, highlight several limitations of the EDX technique in this context, but confirm our interpretation of the data. Finally, we identify differential growth rates as a possible explanation for the concentration/efficiency variations in InGaN layers.

AB - In this letter we discuss the potential and the limitations of quantitative characterization of the distribution of In and Ga atoms in III-N mixed alloys using energy dispersive x-ray (EDX) analysis. Spatial fluctuations of the indium content in an InGaN epilayer are found to correspond to changes in luminescence efficiency. Large hexagonal pyramids, which appear sparsely in such layers, appear to be relatively deficient in indium. Monte Carlo simulations, used to profile the GaKa x-ray fluorescence, highlight several limitations of the EDX technique in this context, but confirm our interpretation of the data. Finally, we identify differential growth rates as a possible explanation for the concentration/efficiency variations in InGaN layers.

KW - InGaN layers

KW - x-ray fluorescence

KW - sapphire

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JF - Applied Physics Letters

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ER -

Energy-dispersive x-ray imaging of an InGaN/GaN bilayer on sapphire

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