Heterostructures of Cu2-xS/Cu2-xTe plasmonic semiconductors: disappearing and reappearing LSPR with anion exchange.

Localized surface plasmon resonance (LSPR) of Cu2-xS nanorods is quenched during the initial Cu2-xS/Cu2-xTe core/shell stage of anion exchange then returns as Cu2-xTe progresses into the nanorod. Phase change within the core accounts for this behaviour illustrating the complexity emergent from anion exchange.