Whether we realize it or not, oxide plasmonic materials are a familiar element in everyday life since transparent conducting oxides (TCOs) are regularly used in liquid-crystal displays.
These materials can exhibit metallic properties in the near-IR when heavily doped.
Doping produces high carrier concentration (N > 1020 cm−3) which results in large plasma frequency(ωp∝√N).
A large plasma frequency results in Drude-metal-like optical properties.
The following equation describes the Drude response of such degenerately doped semiconductors: