Abstract
We investigate visible photoluminescence properties of the AlN films deposited by sputtering. The influence of defects and impurities in the crystal on the visible emission is presented. The photoluminescence spectra show a broad emission band in the range from 2.2 to 3.3 eV, which consists of two components of the bands centered at 2.5 eV and 3.1 eV. When the native defects reduce and the crystal quality is improved by annealing in nitrogen atmosphere, the shoulder band around 2.5 eV declines. The center of luminescence around 3.1 eV shifts to low energy as the oxygen content increases from 1.1 at. % to 8.5 at. %. The intensity and the center of the emission vary mostly linearly with the oxygen content. Combining the results of X-ray diffraction and X-ray photoelectron spectroscopy, the emission around 3.1 eV can be attributed to the transition from the shallow donor to the deep acceptor related to the oxygen impurity, while the emission at 2.5 eV may originate from transition from the shallow donor to the deep acceptor related to the native defect.
Keywords
AlN films, Sputtering, Photoluminescence, X-ray photoelectron spectroscopy.
Citation
DA CHEN, WEI LI, XU YAN, JINGJING WANG, LUYIN ZHANG, The investigation of the visible photoluminescence in AlN films deposited by sputtering, Optoelectronics and Advanced Materials - Rapid Communications, 4, 7, July 2010, pp.960-964 (2010).
Submitted at: April 5, 2010
Accepted at: July 14, 2010