Ab initio investigation of structural and electronic properties of zinc blende AlN1−xBix alloys

In order to predict the structural and electronic properties of AlNBi alloy, we have employed the pseudopotential method as implemented in the Quantum-Espresso code. Lattice parameter for low bismide content (<20%) in AlN has been calculated. It shows an increase with Bi concentration. This variation does not allow Vegardʹs law. We have also calculated the band structure of this alloy. Our calculations indicate that the gap energies decrease with increasing Bi composition. At nearly 2%, a transition from indirect (AlN) to direct (AlNBi) gap is observed. We have also calculated the electron effective masses of the binary compounds and for their ternary alloy as a function of Bi content.