First-Principle Theory Study on Electronic Structure of Ca3Co2O6 and Cu-Doped

Abstract

The relation among electronic structure, chemical bond and thermoelectric property of Ca3Co2O6 and Cu-doped is studied by first-principle theory. The results indicate that the highest valence band(HVB) and the lowest conduction band(LCB) are mainly contributed from Co3d, Cu3d and O2p atomic orbitals and that 1D Co-O chains along c axis play important role in electric property of Ca3Co2O6 and Cu-doped. The property of semiconductor is shown from the gap between HVB and LCB and impurity energy level comes out after Cu-doped and the gap becomes narrower which will increase the mobility of carriers and then decrease the resistivity. The metal characteristics of Cu-doped one are stronger than those of Ca3Co2O6. The thermoelectric property should be improved from adding Cu element into the system of Ca3Co2O6.