A tunable amorphous p-type ternary oxide system: The highly mismatched alloy of copper tin oxide

Patrick J. M. Isherwood, Keith T. Butler, Aron Walsh, John M. Walls
2015 Journal of Applied Physics  
Electrical properties and stability of p-type ZnO film enhanced by alloying with S and heavy doping of Cu The approach of combining two mismatched materials to form an amorphous alloy was used to synthesise ternary oxides of CuO and SnO 2 . These materials were analysed across a range of compositions, and the electronic structure was modelled using density functional theory. In contrast to the gradual reduction in optical band gap, the films show a sharp reduction in both transparency and
more » ... ical resistivity with copper contents greater than 50%. Simulations indicate that this change is caused by a transition from a dominant Sn 5s to Cu 3d contribution to the upper valence band. A corresponding decrease in energetic disorder results in increased charge percolation pathways: a "compositional mobility edge." Contributions from Cu(II) sub band-gap states are responsible for the reduction in optical transparency. V C 2015 AIP Publishing LLC.
doi:10.1063/1.4929752 fatcat:4q4l7b5nu5bstbit5vscj226ym