Structural Phase Transition and a Mutation of Electron Mobility in Zn_xCd_1-xO Alloys

We investigate the electronic structures and phase stability of ZnO, CdO and the related alloys in rocksalt (B1) and wurzite (B4) crystal, using the first-principle density functional theory within the hybrid functional approximation. By varying the concentration of Zn components from 0% to 100%, we find that the Zn_xCd_1-xO alloy undergoes a phase transition from octahedron to tetrahedron at x=0.32, in agreement with the recent experimental findings. The phase transition leads to a mutation of the electron mobility originated from the changes of the effective mass. Our results qualify ZnO/CdO alloy as an attractive candidate for photo-electrochemical and solar cell power applications.