Photoreflectance study of the energy gap and spin-orbit splitting in InNAs alloys

Photoreflectance spectroscopy has been applied to study the energy gap and the spin-orbit splitting in InNAs alloys with the nitrogen concentration changing from 0% to 0.88%. It has been observed that the energy gap of InNAs decreases with the increase in nitrogen concentration (about 60 meV per 1% of nitrogen) but the spin-orbit splitting almost does not change. It shows that nitrogen atoms in InNAs alloys influence mainly the conduction band, i.e., shift this band toward the valence band. The bowing parameter for the energy gap and spin-orbit splitting has been determined to be 7.3±0.6 and −0.7±0.4 eV, respectively.