Cu-Sb-S Ternary Semiconductor Nanoparticle Plasmonics.

Semiconductor plasmonics is a recently emerging field that expands the chemical and physical bandwidth of the hitherto well-established noble metallic nanoparticles. Achieving tunable plasmonics from colloidal semiconductor nanocrystals has drawn enormous interest and is promising for plasmon-related applications. However, realizing this goal of tunable semiconductor nanocrystals is currently still a synthetic challenge. Here, we report a colloidal synthesis strategy for highly dispersed, platelet-shaped, antimony-doped copper sulfide semiconductor nanocrystals (Sby-CuxS NCs) with a dominant localized surface plasmon resonance (LSPR) band tunable from the near-infrared into the midvisible spectral range. This work presents the synthesis and quantifies the resulting plasmonic features. It furthermore elucidates the underlying carrier concentration requirements to realize a continuum of LSPR spectra. Building on our previous work on binary plasmonics CuxS, CuxSe, and CuxTe NCs, the present method introduces a much wider and finer tunability with ternary semiconductor plasmonics.