Ab initio calculation for the decomposition process of GaN (0 0 0 1) and (0 0 0 1¯) surfaces

The activation energies for Ga and N desorption from a GaN surface were calculated using the density functional theory to understand the decomposition process of the GaN(0 0 0 1) and (0 0 0 1¯) Ga- and N-terminated surfaces under a hydrogen atmosphere. It was found that the Ga atoms on the GaN(0 0 0 1) Ga and (0 0 0 1¯) Ga surfaces desorbed as GaH molecules from the surface and the Ga desorption energy for a GaN(0 0 0 1) surface was smaller than that for a GaN(0 0 0 1¯) surface. In the case of N-terminated surfaces, the N atoms on the GaN(0 0 0 1¯) N and (0 0 0 1) N surfaces desorbed as NH3 molecules from the surface and the N desorption energy for a GaN(0 0 0 1) surface was smaller than that for a GaN(0 0 0 1¯) surface.