Optical properties of nonpolar a-plane GaN layers

Authors :: Paskov, Plamen
Paskova, Tanja
Monemar, Bo
Figge, S.
Hommel, D.
Haskell, B.A.
Fini, P.T.
Speck, S.J.
Nakamura, S.
Paskov, Plamen
Paskova, Tanja
Monemar, Bo
Figge, S.
Hommel, D.
Haskell, B.A.
Fini, P.T.
Speck, S.J.
Nakamura, S.
Publication Year :: 2006
Abstract: We have studied optical properties of nonpolar a-plane GaN layers grown on r-plane sapphire by metalorganic chemical vapor deposition and hydride vapor phase epitaxy using different nucleation schemes. Several emission bands, which are not typical for c-plane GaN, are observed in the photoluminescence spectra and their excitation-intensity, temperature, and polarization dependencies are examined. In addition, the spatial distribution of the emissions was examined by cathodoluminescence imaging and relations of the different emissions with particular structural features in the layers are revealed. The results are discussed with emphasis on the origin of the emission line and particular recombination mechanisms. © 2006 Elsevier Ltd. All rights reserved.