Tuning the LSPR in copper chalcogenide nanoparticles by cation intercalation, cation exchange and metal growth

Abstract

Localized surface plasmon resonances (LSPRs) of degenerately doped copper chalcogenide nanoparticles (NPs) (Cu_2−xSe berzelianite and Cu_1.1S covellite) have been modified applying different methods. The comparison of the cation exchange (Cu_2−xSe) and intercalation (Cu_1.1S) of Ag(I) and Cu(I) has shown that Ag(I) causes a non reversible, air stable shift of the LSPR. This was compared to the influence of Au(I) cation exchange into Cu_1.1S platelets under the formation of Cu_1.1S–Au₂S mixed nanoplatelets. Furthermore, we show the growth of Au domains on Cu_2−xSe, and discuss the interaction of the two plasmonic parts of the obtained dual plasmonic Cu_2−xSe–Au hybrid particles.