Composition Dependence of the Band Gap Energy of Dilute Bismuth and Nitride GaNxBiyAs1−y−z Alloy (0 ≤ x ≤ 0.05, 0 ≤ y ≤ 0.05)
The band gap evolution of dilute bismuth and nitride GaNxBiyAs1−x−y alloy is analyzed. It is found that the location of the Г conduction band minimum (CBM) of GaNxBiyAs1−x−y is determined by two factors. One is the influence of the Bi content on the Г CBM of GaAs. The other is the interaction and the hybridization between the N level and the Г CBM of GaBiyAs1−y. For the Г valence band maximum (VBM) of GaNxBiyAs1−x−y, the main factor to determine its location is the interaction and the hybridization between the Bi level and the Г VBM of GaAs. According to the physical mechanism for the band gap evolution, a model is established to depict the band gap energy of GaNxBiyAs1−x−y depending on N and Bi contents quantitatively. The results obtained using the model are consistent with the experimental data.