Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5354440 | Applied Surface Science | 2013 | 7 Pages |
Abstract
In order to study the surface of Ga1âxAlxN photocathodes theoretically, atomic structure, band structure, density of state, surface energy, work function and optical properties of Ga0.75Al0.25N(0Â 0Â 0Â 1) surface are calculated using the plane-wave pseudo-potential method based on the density function theory. It is found that the Ga0.75Al0.25N(0Â 0Â 0Â 1) surface is not flat, the Al atom is more close to N atoms while the Ga atoms are far away from N layer. The surface charges shift from bulk to surface by the effect of dipole moment, the charges of Ga atoms in the top-most layer decrease while that of Al atom change little. The surface energy and work function of Ga0.75Al0.25N(0Â 0Â 0Â 1) are 2.169Â J/m2 and 4.36Â eV respectively. The absorption coefficient of Ga0.75Al0.25N(0Â 0Â 0Â 1) surface is lower than bulk Ga0.75Al0.25N. This provides a theoretical basis for the design and application of Ga1âxAlxN photocathodes.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Yang Mingzhu, Chang Benkang, Hao Guanghui, Guo Jing, Wang Honggang, Wang Meishan,