Indium clustering in a-plane InGaN quantum wells as evidenced by atom probe tomography
Fu, Wai Yuen
Massabuau, Fabien C -P
Martin, Tomas L
Bagot, Paul AJ
Moody, Michael P
Applied Physics Letters
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Tang, F., Zhu, T., Oehler, F., Fu, W. Y., Griffiths, J., Massabuau, F. C. -., Kappers, M., et al. (2015). Indium clustering in a-plane InGaN quantum wells as evidenced by atom probe tomography. Applied Physics Letters, 106 (072104)https://doi.org/10.1063/1.4909514
Atom probe tomography (APT) has been used to characterize the distribution of In atoms within non-polar a-plane InGaN quantum wells (QWs) grown on a GaN pseudo-substrate produced using epitaxial lateral overgrowth. Application of the focused ion beam microscope enabled APT needles to be prepared from the low defect density regions of the grown sample. A complementary analysis was also undertaken on QWs having comparable In contents grown on polar c-plane sample pseudo-substrates. Both frequency distribution and modified nearest neighbor analyses indicate a statistically non-randomized In distribution in the a-plane QWs, but a random distribution in the c-plane QWs. This work not only provides insights into the structure of non-polar a-plane QWs but also shows that APT is capable of detecting as-grown nanoscale clustering in InGaN and thus validates the reliability of earlier APT analyses of the In distribution in c-plane InGaN QWs which show no such clustering.
Quantum wells, Cluster analysis, Epitaxy, Statistical analysis, Transmission electron microscopy
The European Research Council has provided financial support under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 279361 (MACONS). This work was also funded in part by the EPSRC (Grant Nos. EP/H047816/1, EP/H0495331 and EP/J003603/1).
European Research Council (279361)
External DOI: https://doi.org/10.1063/1.4909514
This record's URL: https://www.repository.cam.ac.uk/handle/1810/247730