Photoluminescence studies of GaN epilayer-nanocrystals grown on γ-LiAlO2 substrate
Journal
Physica E: Low-Dimensional Systems and Nanostructures
Journal Volume
40
Journal Issue
6
Pages
1971-1974
Date Issued
2008
Author(s)
Abstract
We report the optical studies of the properties of M-plane GaN/c-plane GaN nanocrystal heterostructure on γ-LiAlO2 substrate grown by plasma-assisted molecular beam epitaxy. In this structure, in addition to the M-plane epilayer, nanocrystals grown in c-direction could also be observed in the step edges of the M-plane GaN terraces and the hexagonal basis of the γ-LiAlO2 substrate. X-ray diffraction (XRD) with peaks at 2θ=32.295°, 34.680° and 34.505° are attributed to the M-plane GaN, LiAlO2 and c-plane GaN, respectively. Two peaks were observed in the photoluminescence spectra at low temperature. The peak at 3.33 to 3.35 eV is attributed to the emission from c-plane GaN nanocrystals and the peak at 3.50 eV is attributed to the emission from M-plane GaN epilayers. The relative intensity of these peaks is position-dependent. In the area with higher concentration of the GaN nanocrystals the emission for the nanocrystals is stronger and vice versa. Cathodoluminescence shows that the emission peak at 3.33-3.35 eV is originated from the nanocrystals GaN. © 2007 Elsevier B.V. All rights reserved.
Subjects
GaN; LiAlO2; Nanocrystal; Photoluminescence
SDGs
Other Subjects
Cathodoluminescence; Crystal growth; Epilayers; Gallium nitride; Heterojunctions; Lithium compounds; Molecular beam epitaxy; Photoluminescence; Emission peaks; Photoluminescence spectra; Nanocrystalline materials
Type
journal article