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

Highlight•Effects of Mn on GaAs under high-pressure are reducing of band gap, generating of impurity peak and increasing of photoabsorption coefficient.•The impurity peaks occurred due to the available states of d orbitals from the Mn impurity.•The electronic states are spread out in the energy axis; as a result, the impurity peaks were reduced by high pressure effect.•The tendency of photo absorption under pressure depends on the magnitude of impurity peaks.

Ab initio calculation based on density functional theory was performed for studying high-pressure effects on the electronic properties and photoabsorption of Ga1−xMnxAs. 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 Ga1−xMnxAs, 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 Ga1−xMnxAs 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 Ga1−xMnxAs in range of light-wavelength depends on size of impurity peak.