Projects per year
Doped semiconductor nanocrystals represent an exciting new type of plasmonic material with optical resonances in the infrared. Unlike noble metal nanoparticles, the plasmon resonance can be tuned by altering the doping density. Recently, it has been shown that silicon nanocrystals can be doped using phosphorus and boron resulting in highly tunable infrared plasmon resonances. Due to the band structure of silicon, doping with phosphorus contributes light (transverse) and heavy (longitudinal) electrons, while boron contributes light and heavy holes and one would expect two distinct plasmon branches. Here we develop a classical hybridization theory and a full quantum mechanical TDLDA approach for two-component carrier plasmas and show that the interaction between the two plasmon branches results in strongly hybridized plasmon modes. The antibonding mode where the two components move in phase is bright and depends sensitively on the doping densities. The low energy bonding mode with opposite charge alignment can only be observed in the quantum regime when strong Coulomb screening is present. The theoretical results are in good agreement with the experimental data.
Bibliographical noteFunding Information:
The use of beamline 11-ID-B of the Advanced Photon Source, a U.S. Department of Energy (DOE), Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory was facilitated under Contract No. DE-AC02-06CH11357.
© 2017 American Chemical Society.
- plasmon hybridization
- quantum dots
- silicon nanocrystals
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 4