Abstract GaN epitaxial layers on GaN single crystals were grown using molecular beam epitaxy with an NH 3 source. In the higher energy range we observed three strong lines. Their energetic positions are characteristic of strain-free GaN material. In this work we report first MBE grown homoepitaxial GaN film.
Larger crystals become slightly mosaic and have small angle boundaries.
Additionally, a strong yellow luminescence is always observed. For our investigation we used a Riber 32 MBE system adapted for group V gas sources. The system is turbopumped and the attached gas control and handling system is home made. The MBE system is equipped with Knudsen cells used to evaporate Ga, Al, In and Mg. This system was previously used for growing GaN layers on sapphire.