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Molecular Beam Epitaxial Growth of High-Quality GaN Nanocolumns



J E. Van Nostrand, J. E. Averett, R Cortez, J. Boeckl, C Stutz, Norman Sanford, Albert Davydov, M M. Maska


Vertically oriented gallium nitride GaN nanocolumns (NCs) approximately 90±10 nm wide and 0.75 microns tall were grown by plasma-assisted molecular beam epitaxy on Al_(2)O_(3)(0001) and Si(111). The dense packing of the NCs gives them the appearance of a continuous film in surface view, but cross-sectional analysis shows them to be isolated nanostructures. Low-temperature photoluminescence measurements of NCs show excitonic emission with a dominant, narrow peak centered at 3.472 eV and FWHM of 1.26 meV. This peak is identified as the ground state of the A free exciton as confirmed by reflection measurements. Cross-sectional transmission electron microscopy identifies the NC microstructure as wurtzite GaN and that the NCs are largely free of defects. The GaN NCs are subsequently utilized as a defect-free vehicle for optical studies of Si-doped GaN; and the donor state was identified through low-temperature photoluminescence experiments.
Journal of Crystal Growth


GaN nanocolumns, GaN photoluminescence, transmission electron microscopy


Van Nostrand, J. , Averett, J. , Cortez, R. , Boeckl, J. , Stutz, C. , Sanford, N. , Davydov, A. and Maska, M. (2006), Molecular Beam Epitaxial Growth of High-Quality GaN Nanocolumns, Journal of Crystal Growth, [online], (Accessed June 18, 2024)


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Created January 4, 2006, Updated October 12, 2021