Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1552621 | Superlattices and Microstructures | 2016 | 8 Pages |
Abstract
Yttrium (Y) adsorption and yttrium nitride (YN) thin film formation on the GaN(0001¯) surface are investigated using first principles total energy calculations. Results show that for Ga rich conditions the most stable configuration for Y adsorption is at a Bridge site. Nudged elastic band calculations show that the Y diffusion through the GaN surface is possible with low energy barriers. However, the most stable configuration corresponds to the geometry in which the Y atom migrates in to the first layer, forming an YN pair and displacing a Ga atom to the T4(2) site. Also, it is found that the increase of Y atoms up to a full monolayer is not energetically favorable, then the formation of an Y layer on top of the surface is not possible. However, under N-rich conditions the formation of a cubic-like YN bilayer above the surface becomes stable. Total and partial density of states show that the formation of YN on top of the Ga-terminated surface modify the electronic properties. Nevertheless, metallic behavior remains after YN formation.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
J. Guerrero-Sánchez, Gregorio H. Cocoletzi, J.F. Rivas-Silva, Noboru Takeuchi,