A tunable amorphous p-type ternary oxide system: The highly mismatched alloy of copper tin oxide
- Authors
- Publication Date
- Aug 17, 2015
- Identifiers
- DOI: 10.1063/1.4929752
- OAI: oai:spiral.imperial.ac.uk:10044/1/49090
- Source
- UPCommons. Portal del coneixement obert de la UPC
- Keywords
- License
- Unknown
Abstract
The approach of combining two mismatched materials to form an amorphous alloy was used to synthesise ternary oxides of CuO and SnO2. 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 electrical 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.
