Large-scale AlN nano-tip arrays were fabricated via an easy catalysis-free approach using AlCl3 powder and NH3 as starting materials. These nano-tips exhibited two intense broad emissions centred at about 375 and 480nm. Neither band changed significantly or froze out at a low temperature, showing the features of photo-ionization of deep donor electrons. Photoluminescence and photoluminescence excitation spectral examination as well as the possible mechanism involved were systematically investigated. It revealed that the two bands were connected with the electronic states determined by the nitrogen vacancy and complex defects. The related energy structures were also provided. This work provided a possible mechanism for defect-related emissions in various AlN nanostructures.

Defect-Related Energy Structures of AlN Nanotips Probed by Photoluminescence. H.Chen, G.Chen, X.Zhou, W.Zhu, X.Chen, X.Zeng: Journal of Physics D, 2011, 44[50], 505304