Effect of nitrogen on the band structure of GaInNAs alloys

We show that incorporation of nitrogen in ${\mathrm{Ga}}_{\text{1−x}}{\mathrm{In}}_x\mathrm{As}$ to form ${\mathrm{Ga}}_{\text{1−x}}{\mathrm{In}}_x{\mathrm{N}}_y{\mathrm{As}}_{\text{1−y}}$ alloys leads to a splitting of the conduction band into two nonparabolic subbands. The splitting can be described in terms of an anticrossing interaction between a narrow band of localized nitrogen states and the extended conduction-band states of the semiconductor matrix. The downward shift of the lower subband edge accounts for the N-induced reduction of the fundamental band-gap energy. An analysis of the relationship between the subband splitting and the band-gap reduction demonstrates that the energetic location of the valence band is nearly independent of the N content in ${\mathrm{Ga}}_{\text{1−x}}{\mathrm{In}}_x{\mathrm{N}}_y{\mathrm{As}}_{\text{1−y}}$ alloys.