(Invited) Manipulating Carrier Polarization in Semiconductor Nanocrystals

Abstract

We investigated the role of the synthesis method and post-synthesis processing on the plasmonic properties of antimony-doped SnO2 nanocrystals. The nanocrystal samples having variable doping concentrations were prepared by coprecipitation and solvothermal methods, and subsequently thermally annealed for different durations. We found that solvothermally-synthesized Sb-doped SnO2 nanocrystals exhibit strong localized surface plasmon resonance in the near-infrared region, which is distinctly absent in the nanocrystals synthesized by the coprecipitation method. Upon thermal annealing, the plasmon absorption emerges in the nanocrystals prepared by the coprecipitation method, and increases in intensity in solvothermally-synthesized nanocrystals. Using X-ray photoelectron spectroscopy, we correlated the plasmon intensity to the oxidation of Sb3+ to Sb5+. These results demonstrate that synthesis methodology and post-synthesis treatment can dramatically influence the plasmonic properties of aliovalently-doped semiconductor nanocrystals via dopant oxidation state, and can be effectively used to design semiconductor nanocrystals with targeted plasmonic properties.