Scaling of phonon frequencies and electron binding energies with interatomic distances in InxGa1-xN

In-K-edge x-ray absorption fine structure (EXAFS), x-ray photoelectron, and Raman spectroscopy results are combined for a comprehensive study of InxGa1-xN layers with energy gaps extending over nearly the whole visible spectrum. The In-N and In-(In,Ga) distances determined by EXAFS are used for the derivation of the In-N bond ionicity as well as for the phonon frequency dependence of the LO and B 1 2 modes, assessed by Raman, and the N 1s, In 3d(5/2), Ga 3s, and Ga 2p(1/2) electron binding energies on those distances. Phonon confinement due to perturbation of the periodic potential caused by the alloying is also quantified.