Lattice strain and p-d repulsion affecting electronic structure of wurtzite Zn_1-xCd_xO alloys

In the paper, density of states, band structure and electron density difference of Zn_1-xCd_xO are calculated by first principles, here x varies from 0 to 0.75 at intervals of 0.125, and the band gap obtained from band structure changes from 0.968 eV to 0.043 eV. The lattice strain and p-d repulsion theory are used to investigate variation of the band gap, the results obtained show that the variation is mainly due to the lattice tensile strain. The p-d repulsion in Zn_1-xCd_xO cannot be neglected. In addition, electron density difference can be used to verify the results.