The relationship between epitaxial growth, defect microstructure and luminescence in GaN

MBE grown epitaxial GaN has been characterised by a variety of microscopies. Large scale features such as zincblende inclusions in wurtzite GaN are revealed by a combination of RHEED, SEM/CL and conventional TEM. Substrate pitting is best characterised by optical microscopy coupled with plan view TEM of samples prepared through the interface plane. Plan view HREM combined with g.R or g.b analysis of cross-sectional samples clarifies the displacements associated with prismatic stacking faults and threading dislocations. High spatial resolution EELS and CL provide insight into the effect of defects on material spatial or spectral purity.