Molecular Beam Epitaxial Growth of High-Quality GaN Nanocolumns
J E. Van Nostrand, K L. Averett, R Cortez, J Boecki, C E. Stutz, Norman Sanford, Albert Davydov, J D. Albrecht
Vertically oriented GaN nanocolumns (NCs) approximately 90+10 nm wide and 0.75 microns tall were grown byt 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, K.
, Cortez, R.
, Boecki, J.
, Stutz, C.
, Sanford, N.
, Davydov, A.
and Albrecht, J.
Molecular Beam Epitaxial Growth of High-Quality GaN Nanocolumns, Journal of Crystal Growth
(Accessed December 2, 2023)