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

Abstract

A model is developed to describe the pressure dependence of the band gap energy for the dilute nitride GaN x As 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 x As 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 Γ CBM in GaN x As 1−x is larger than that in GaAs. In addition, we explain the phenomenon that the energy difference between the X CBM and the Γ CBM in GaN x As 1−x is larger than that in GaAs. It is due to the impurity-host interaction.

Pressure dependence of the band gap energy for dilute nitride and antimony GaNxSbyAs1−x−y

“…At standard atmospheric pressure, a rapid decline of the Γ CBM of GaN x Sb y As 1−x−y with increasing N content is due to the strong N-Γ CBM coupling interaction. It is well known that the X CBM of dilute nitride GaN x Sb y As 1−x−y evolves from the X CBM of GaAs, which is very similar to the X CBM of the dilute nitride GaN x As 1−x and GaN x P 1−x [14,[16][17][18]. As the energy of the X CBM of GaAs is higher than that of the N level, the N-X CBM coupling interaction could inhibit the downward movement of the X CBM of GaN x Sb y As 1−x−y Based on the above analysis, it can be seen that the X CBM of GaN x Sb y As 1−x−y decreases much more slowly than the Γ CBM of GaN x Sb y As 1−x−y , causing that the X-Γ CBM energy difference in GaN x Sb y As 1−x−y is larger than that in GaAs.…”