Ab initio study of electronic density of state and photoabsorption of Ga1−xMnxAs under pressure

Abstract Ab initio calculation based on density functional theory was performed for studying high-pressure effects on the electronic properties and photoabsorption of Ga 1− x Mn x As. Mn atom was substituted into the varied GaAs super cells, which observed the Mn concentrations at 3.70%, 8.33% and 12.50%. In zinc blende phase of Ga 1− x Mn x As, we found that the effects of Mn on GaAs in the pressure range 0–10 GPa are the reducing of band gap, generating of impurity peak and increasing of photoabsorption coefficient. The impurity peaks in Ga 1− x Mn x As decrease under pressure increasing because the carriers were excited to conduction band by the effect of bond lengths reducing. The tendency of absorption coefficient of Ga 1− x Mn x As in range of light-wavelength depends on size of impurity peak.