Effect of band anticrossing on the optical transitions in GaAs1-xNx/GaAs multiple quantum wells

Interband transitions in ${\mathrm{GaAs}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}/\mathrm{GaAs}$ multiple quantum wells were studied at room temperature by photomodulated reflectance spectroscopy as a function of well width (3--9 nm), the nitrogen concentration $(0.012lxl0.028),$ and hydrostatic pressure (0--64 kbar). All experimental data can be quantitatively explained using the dispersion relationship obtained from a band anticrossing model to calculate electron confinement effects in a finite depth quantum well. The results are consistent with a nitrogen-induced large increase of the electron effective mass in the GaAsN quantum wells.