Material properties of Cd1−xMgxO transparent conductors

We have studied structural, electrical and optical properties of ternary Cd1-xMgxO alloy thin films synthesized by radio frequency magnetron sputtering method with Mg content as high as x=0.44. We found that only a fraction (50-60%) of Mg is incorporated as substitutional Mg contributing to the modification of the electronic structure of the alloy. The electrical and optical results of the Cd1-xMgxO alloys are analyzed in terms of a large upward shift of the conduction band edge with increasing Mg content. The rapid increase of the optical band gap offers a potential of using Cd-rich CdMgO alloys as transparent conductors for photovoltaics.