Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Alloy inhomogeneity and carrier localization in AlGaN sections and AlGaN/AlN nanodisks in nanowires with 240–350 nm emission

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4904989· OSTI ID:22395528
We present structural and optical studies of AlGaN sections and AlGaN/AlN nanodisks (NDs) in nanowires grown by plasma-assisted molecular beam epitaxy. The Al-Ga intermixing at Al(Ga)N/GaN interfaces and the chemical inhomogeneity in AlGaN NDs evidenced by scanning transmission electron microscopy are attributed to the strain relaxation process. This interpretation is supported by the three-dimensional strain distribution calculated by minimizing the elastic energy in the structure. The alloy inhomogeneity increases with the Al content, leading to enhanced carrier localization signatures in the luminescence characteristics, i.e., red shift of the emission, s-shaped temperature dependence, and linewidth broadening. Despite these effects, the emission energy of AlGaN/AlN NDs can be tuned in the 240–350 nm range with internal quantum efficiencies around 30%.
OSTI ID:
22395528
Journal Information:
Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 24 Vol. 105; ISSN APPLAB; ISSN 0003-6951
Country of Publication:
United States
Language:
English