Open Access Nano Express

Cathodoluminescence spectra of gallium nitride nanorods

Chia-Chang Tsai1, Guan-Hua Li1, Yuan-Ting Lin1, Ching-Wen Chang1, Paritosh Wadekar1, Quark Yung-Sung Chen1, Lorenzo Rigutti2, Maria Tchernycheva2, François Henri Julien2 and Li-Wei Tu1*

Author Affiliations

1 Department of Physics and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan, 80424, Republic of China

2 Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud XI, Orsay Cedex, 91405, France

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Nanoscale Research Letters 2011, 6:631  doi:10.1186/1556-276X-6-631

Published: 14 December 2011

Abstract

Gallium nitride [GaN] nanorods grown on a Si(111) substrate at 720°C via plasma-assisted molecular beam epitaxy were studied by field-emission electron microscopy and cathodoluminescence [CL]. The surface topography and optical properties of the GaN nanorod cluster and single GaN nanorod were measured and discussed. The defect-related CL spectra of GaN nanorods and their dependence on temperature were investigated. The CL spectra along the length of the individual GaN nanorod were also studied. The results reveal that the 3.2-eV peak comes from the structural defect at the interface between the GaN nanorod and Si substrate. The surface state emission of the single GaN nanorod is stronger as the diameter of the GaN nanorod becomes smaller due to an increased surface-to-volume ratio.

Keywords:
gallium nitride; nanorod; cathodoluminescence; scanning electron microscopy