Study of local segregation in GaInNAs using EXAFS measurements

We investigated the local atomic arrangements around In atoms of plasma-assisted molecular beam epitaxy (MBE) grown GaInNAs films using In K-edge extended X-ray absorption fine structure (EXAFS) oscillations. The obtained radial distribution function (RDF) clearly showed two peaks coming from the first nearest In-As bond and the second nearest In-cation bond. These two atomic distances were longer than the bond lengths theoretically calculated under an assumption of random distributions of Ga and In on cation sites and N and As on anion sites, respectively. It means that there are strong In-N and In-In correlations in GaInNAs films. The strong correlations suggest the formation of the InNAs-like particles, which can cause the spacially inhomogeneous emission.