Optical Modeling of Plasmonic Nanoparticles with Electronically Depleted Layers

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Doped metal oxide (MO) nanocrystals (NCs) exhibit localized surface plasmon resonance (LSPR) in the infrared range due to free electrons.
• LSPR is intrinsically linked to the carrier density profile within the NCs.
• The electronic structure of MO NCs is influenced by surface Fermi level pinning, creating a depleted layer.

Purpose of the Study:

• To systematically investigate the influence of simulation parameters on optical modeling of MO NCs.
• To understand how carrier density profiles, particularly the depleted layer, affect plasmonic features.
• To validate a multilayer model for accurately describing experimental absorption spectra.

Main Methods:

• Implementation of multilayer models for optical simulations.
• Systematic study of simulation parameter influence on absorption spectra.
• Analysis of experimental absorption spectra of representative MO NCs.

Main Results:

• The depleted layer is fundamental for correctly describing the evolution of continuous spectra.
• Minimizing fit parameters with experimental support and understanding interparameter relationships are crucial for accurate modeling.
• Tuning dopant concentrations in core-shell architectures spatially engineers carrier profiles and plasmonic features.

Conclusions:

• The developed multilayer model accurately describes plasmonic features in MO NCs.
• The depleted layer's role is critical for accurate optical modeling.
• This model can guide the design of optoelectronic properties in core-shell systems through band and depletion layer engineering.