Abstract:
A study of the relationship between strain and the incorporation of group III elements in ternary InGaN and InAlN grown by molecular beam epitaxy is reported. Using X-ray Photoelectron Spectroscopy compositional depth profiles with x-ray diffraction, we are able to find a clear relationship between strain and In incorporation including tensile-strained InAlN which has, to date, not been studied. The results show that fully strained films contain homogeneous indium composition while partially relaxed films have a non-homogeneous indium composition with depth. These results can be interpreted by considering the impurity formation energies of indium in host lattices.