Effect of Nitrogen on the Band Structure of GaInNAs Alloys

We show that incorporation of nitrogen in Ga_1-xIn_xAs to form Ga_1-xIn_xN_yAs_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 Ga_1-xIn_xN_yAs_1-y alloys.