Spectroscopic ellipsometry in the mid-infrared and near-infrared to vacuum-ultra violet spectral range is employed to study the phonon properties and critical points of a GaP0.977N0.023 layer grown on GaP. We observe a two-mode phonon behaviour, i.e., a GaN-like and a GaP-like phonon. We detect six critical-point structures, which we assign as Edir0, E′0, E1, E′1, E12 and E22 transitions. We observe a blueshift of the direct band gap Edir0 and of the E1 transition in contrast to the redshift of the photoluminescence peak and the absorption tail, which we observed on the same sample. The critical-point energies E′0 E′1, and E2 do not show any significant composition dependence.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physica Status Solidi (B) Basic Research|
|Publication status||Published - Nov 2001|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics