Combined raman study of InGaAsN from the N-impurity and InGaAs-matrix sides
Résumé
The authors report a Raman study of In0.08Ga0.92As0.98N0.02 covering both N- and InGaAs-related spectral ranges, supported by ab initio and phenomenological modeling of the spectra. The authors argue that the crystal self-organizes at different scales to reduce the N-induced strain. Locally, this is achieved by In-N-Ga-3 configurations, as is well known. Moreover, a long scale organization occurs in the InGaAs matrix, away from N. This is apparent in the over representation of the ``short'' Ga-As bonds from the In-rich region, as compared with random InGaAs. Quantitative insight is derived at the mesoscopic scale from the 1-bond -> 2-phonon ``percolation''-type behavior of the dominant Ga-As species. (c) 2007 American Institute of Physics.