Evidence of terbium and oxygen co-segregation in annealed AlN:Tb

Analytical scanning transmission electron microscopy has been applied to study aluminium nitride (AlN) doped with terbium (Tb) and annealed at 800 ºC. The correlation of the maps of Tb and oxygen (O) from electron energy-loss spectrum (EELS) imaging proves that these two elements co-segregate, replacing aluminium (Al) and nitrogen (N) atoms, respectively. This agrees well with modelling which predicted the existence of Tb–O complexes needed to fit all lines in the rather complicated cathodoluminescence emission spectrum of the sample