We study the phonon properties of compressively strained InxGa1-xAs1-yNy (x < 0.13, y < 0.03) single layers for wavenumbers from 100 to 600 cm-1 using far infrared spectroscopic ellipsometry. The intentionally undoped InGaAsN layers were grown pseudomorphically on top of undoped GaAs buffer layers deposited on Te-doped (001) GaAs substrates by metal-organic vapor phase epitaxy. The InGaAsN layers show a two-mode phonon behaviour in the spectral range from 100 to 600 cm-1. We detect the transverse GaAs and GaN sublattice phonon modes at wavenumbers of about 267 and 470 cm-1, respectively. The polar strength f of the GaN sublattice resonance changes with nitrogen composition y and with the biaxial strain εxx resulting from the lattice mismatch between InGaAsN and GaAs. This effect can be used to derive the nitrogen and indium content of the InGaAsN layers combining the observed f-dependence with results from high-resolution double-crystal X-ay diffractometry.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physica Status Solidi (B) Basic Research|
|State||Published - Nov 2001|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics