GaN single crystals grown under moderate nitrogen pressure by a new flux: Ca3N2

Using a new flux, Ca3N2, bulk GaN crystals were grown from Ga melt at 900 °C under a nitrogen pressure of about 0.2 MPa. Optical observations indicated that the grown GaN crystals were transparent hexagonal prisms with length up to 1.5 mm. The morphology of these GaN crystals was characterized by scanning electron microscopy (SEM) and compared with that of GaN crystals grown by using Li and Na flux. Raman scattering examinations revealed that the GaN crystals grew along [0 0 0 1] direction. These results demonstrated that Ca3N2 was an effective new flux in the crystal growth of GaN besides the known fluxes of Li, Na and Na–Ca.