Pressure dependence of the band gap energy for the dilute nitride GaN_xAs_1−x

A model is developed to describe the pressure dependence of the band gap energy for the dilute nitride GaN_xAs_1–x. It is found that the sublinear pressure dependence of E₋ is due to the coupling interaction between E₊ and E₋. We have also found that GaN_xAs_1−x needs much larger pressure than GaAs to realize the transition from direct to indirect band gap. It is due to two factors. One is the coupling interaction between the E₊ and E₋. The other is that the energy difference between the X conduction band minimum (CBM) and the G CBM in GaN_xAs_1−x is larger than that in GaAs. In addition, we explain the phenomenon that the energy difference between the X CBM and the G CBM in GaN_xAs_1−x is larger than that in GaAs. It is due to the impurity-host interaction.