Growth and characterization of a-plane AlxGa1−xN alloys by metalorganic chemical vapor deposition

Autor: Jui-Yuan Chen, Huei Min Huang, Tien-Chang Lu, S. C. Wang, Jinchai Li, Hao-Chung Kuo, Shih-Chun Ling, Tsung-Shine Ko
Rok vydání: 2010
Předmět:
Zdroj: Journal of Crystal Growth. 312:869-873
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2009.12.064
Popis: The non-polar a -plane Al x Ga 1− x N alloys on GaN epitaxial layer with different Al compositions (0≤ x ≤0.2) were grown on r -plane (1 1¯ 0 2) sapphire substrates by using low-pressure metalorganic chemical vapor deposition (MOCVD) and the Al composition x were estimated from the X-ray diffraction measurements. According to the result of asymmetric X-ray reciprocal space mapping, AlGaN layer was coherently strained to the underlying GaN template. The a -plane AlGaN alloy with relatively lower Al composition showed a flat surface with reduction of pits. The best mean roughness of the surface morphology was 1.18 nm. The photoluminescence (PL) result revealed that the PL peak position shifted from 3.42 to 3.87 eV with 0≤ x ≤0.2. Apart from the shifted peak position with increasing Al content, the PL emission intensity and surface morphology of the a -plane AlGaN alloy with relatively low Al content show slightly better characteristics than that of the a -plane GaN and AlGaN with higher Al composition.
Databáze: OpenAIRE