First-principles electronic structure and formation energies of group V and VII impurities in the α-Fe2O3 alloys

Based on density functional theory, the electronic structures, formation energy, and transition level of the selected group V and VII impurities in α-Fe2O3 are investigated by means of first-principles methods. Numerical results show that the group V and VII atoms-doped α-Fe2O3 can be energetically favorable under the Fe-rich condition. Group V atom substituting O atom can induce the acceptor impurity level, while the deep donor impurity states are formed inside the band gap when group VII atom substitute O atom in the α-Fe2O3. Moreover, our results show that halogen atom F substituting O atom should be very easy in the α-Fe2O3. In addition, our results also show that for both group V and VII atom-doped α-Fe2O3, the upper sides of valence band are modified obviously, while the conduction band edge does not change.