MBE growth of cubic GaN on GaAs substrates

We review our recent results on plasma‐assisted molecular beam epitaxy of cubic GaN films on GaAs(001). The crucial role of the nucleation stage for obtaining epitaxial growth is highlighted by reflection high‐energy electron diffraction and transmission electron microscopy. For the subsequent growth, it is found that the surface stoichiometry determines the phase composition of the epilayers as determined by X‐ray reciprocal space mapping, Raman and cathodoluminescence spectroscopy. For an in situ control of the surface stoichiometry, we develop a method based on the transitions of the surface reconstructions of cubic (001)GaN. Films grown under conditions optimized by this method are single‐phase cubic and exhibit intense excitonic luminescence up to room temperature.