Structural and optical properties of nonpolar (1 1 −2 0) a-plane GaN grown on (1 −1 0 2) r-plane sapphire substrate by plasma-assisted molecular beam epitaxy

• Published in: Scripta materialia Vol. 65; no. 1; pp. 33 - 36
• Main Authors: Rajpalke, Mohana K., Roul, Basanta, Kumar, Mahesh, Bhat, Thirumaleshwara N., Sinha, Neeraj, Krupanidhi, S.B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2011
• Subjects: Emission spectroscopy; Epitaxial growth; Gallium nitrides; High-resolution X-ray diffraction; Molecular beam epitaxy; Nonpolar GaN; Optical properties; Photoluminescence; Raman spectroscopy; Sapphire; Stacking faults; Molecular beam epitaxy; High-resolution X-ray diffraction; Nonpolar GaN; Photoluminescence
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/j.scriptamat.2011.03.017

► Structural and optical study of a-plane GaN film grown on r-sapphire by PAMBE. ► HRXRD was used to determine the epitaxial relation of a-plane GaN with r-sapphire. ► The plane-view TEM reveals the formation of basal stacking faults in a-plane GaN. ► Low temperature PL emission was found to be dominated by basal stacking faults. ► Raman spectroscopy study shows that a-GaN film is compressively strained.
We report the structural and optical properties of
a-plane GaN film grown on
r-plane sapphire substrate by plasma-assisted molecular beam epitaxy. High resolution X-ray diffraction was used to determine the out-of-plane and in-plane epitaxial relation of
a-plane GaN to
r-plane sapphire. Low-temperature photoluminescence emission was found to be dominated by basal stacking faults along with near-band emission. Raman spectroscopy shows that the
a-GaN film is of reasonably good quality and compressively strained.