Low-Loss Tunable Infrared Plasmons in the High-Mobility Perovskite (Ba,La)SnO₃

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Barium stannate (BaSnO3) is a promising perovskite oxide for electronics due to its high carrier mobility.
• Plasmons, collective electron oscillations, are crucial for manipulating light at the nanoscale, with potential in optoelectronics.

Purpose of the Study:

• To demonstrate the existence of long-lived plasmons in La-doped BaSnO3 (BLSO).
• To investigate the properties of infrared localized surface plasmons (LSPs) in BLSO nanoparticles.

Main Methods:

• Utilized electron energy-loss spectroscopy (EELS) with high spatial and energy resolution in a scanning transmission electron microscope.
• Systematically studied the dispersion, confinement ratio, and damping of LSPs in BLSO nanoparticles.

Main Results:

• Confirmed the presence of relatively long-lived plasmons in BLSO, supported by high-mobility charge carriers.
• Observed that BLSO's LSPs exhibit superior spatial confinement compared to noble metals.
• Found that BLSO sustains LSPs with low losses and high quality factors, outperforming other doped oxides.

Conclusions:

• Established a clear relationship between plasmon damping and carrier mobility in BLSO.
• Validated the use of nanostructured degenerate semiconductors for infrared plasmonics.
• Positioned BLSO as a viable alternative to conventional plasmonic materials.