TD-DFTB study of optical properties of silver nanoparticle homodimers and heterodimers
Abstract
The absorption spectra for face-centered cubic nanoparticle dimers at various interparticle distances are investigated using time-dependent density functional tight binding. Both homodimers and heterodimers are investigated in this work. By studying nanoparticles at various interparticle distances and analyzing their vertical excitations, we found that as the interparticle distance decreases, a red shift arises from contributions of the transition dipole moment that are aligned along the z-axis with nondegenerate features; blue shifts occur for peaks that originate from transition dipole moment components in the x and y directions with double degeneracy. When the nanoparticles are similar in size, the features in the absorption spectra become more sensitive to the interparticle distances. The best-fit curves from vertical excitation energy in the form of AR−b for ΔEredshift/ΔEblueshift vs R are determined. In this way, we determined trends for absorption peak shifts and how these depend on the interparticle distance.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 14, 2020
- Source ID
- 10.1063/5.0025672
Entities
People
- Christine M Aikens
- Fahri Alkan
- Zhen Liu
Organizations
- Abdullah Gül University
- Air Force Office of Scientific Research
- Kansas State University
- National Science Foundation Directorate for Mathematical & Physical Sciences