Local structure of indium in quinary (InGa)(AsSbN)/GaAs quantum wells

We performed In K-edge x-ray absorption fine-structure spectroscopy on (InGa)(AsSbN)/GaAs quinary quantum well samples exposed to annealing of different durations, in order to investigate their microstructures. Spectra neither evidence large modification as a function of annealing, nor are sensitive to In-N preferential ordering with the concentration at play. Nevertheless, we observed a shoulder on the low-R side of the Fourier-transformed spectra of all samples. This feature can be properly simulated under the hypothesis of formation of a complex where In atoms see a heavy nearest neighbor at a rather short distance. Mass and distance of the complex are compatible with a Sb-N split interstitial with the Sb atom located close to In. The concentration of this complex structure (roughly 2–3 % of the total In atoms) does not change substantially after the 800 °C annealing processes.