Structure and chemistry of the $(111)Sc2O3/(0001)$ GaN epitaxial interface

The structure and chemistry of the $(111)Sc2O3/(0001)$ GaN epitaxial interface grown by molecular-beam epitaxy have been investigated. High-resolution transmission electron microscopy reveals an abrupt $Sc2O3/GaN$ interface with a hexagonal misfit dislocation network. These dislocations have Burgers vectors of $(a/3)⟨112¯0⟩GaN$ and line directions parallel to $⟨11¯00⟩GaN$⁠, with an average spacing of $∼3.8nm$⁠. Scanning transmission electron microscopy and electron energy loss spectrometry reveal the intermixing of Sc, O, and N over a region with a width of $∼1.5nm$ at the interface.