Valence-band splitting and shear deformation potential of dilute GaAs1-xNxalloys

The valence-band splitting in thin GaAs1-xNx (0.011 less than or equal to x less than or equal to 0.033) epilayers strained coherently by the GaAs sub strate is observed in electroreflectance. This study reveals that the valen ce-band deformation potential does not follow the linear interpolation of t hose for GaAs and GaN, but shows a rather strong composition dependence wit h a surprising bowing in a small composition region of the alloy. These res ults contradict the currently held view that the conduction band is greatly altered but that the valence band is only weakly perturbed by dilute nitro gen doping of GaAs.