Fluorination of the exterior surface of AlN nanotube: A DFT study

Fluorination of a zigzag AlN nanotube (AlNNT) with one to four F atom(s) has been investigated using density functional theory in terms of energetic, geometric, and electronic properties. The results show that the F atoms preferably tend to be chemisorbed on Al atoms of the tube surface, releasing energies in the range of 3.79-4.25 eV per adsorbed atom along with charge transferring from the tube to the F atoms. Density of states analysis reveals that: (1) HOMO/LUMO energy gap (E-g) of the tube is reduced in all of the cases for F adsorptions. (2) The decrement of E-g depends on the number of adsorbed F atoms so that it is much more reduced when their number is odd. (3) Fluorination of the tube with odd number of F atoms transforms it to a p-type semiconductor with much narrower E-g. However, our results may lead to a new approach to tune the electronic properties of AlNNTs toward some modified nanoelectronic materials. (C) 2012 Elsevier Ltd. All rights reserved.