Modification of the surface energy and morphology of GaN monolayers on the AlN surface in an ammonia flow

Based on theoretical predictions, it has been demonstrated that it is possible to purposefully change the elemental composition and position of the adsorbed particles on the GaN surface, thereby controlling the surface energy and morphology of GaN. Comparison of experimental data obtained by reflected high-energy electron diffraction and the calculated concentration of ammonia fragments on the GaN surface, and surface energy showed that the movement of adsorbed ammonia fragments into strongly bound states is an effective mechanism to control the GaN morphology. The minimum value of equivalent NH₃ beam pressure at different temperatures to prevent the conversion of the two-dimensional (2D) GaN layer to three-dimensional (3D) islands has been established. It was shown that the boundary between the 2D and 3D states on the surface is defined by the elemental composition of adsorbed particles on the surface and the temperature dependence of the surface energy of the facets of islands.