Continuous Anisotropic Growth of Plasmonic CsWO_3-δ Nanocrystals into Rods and Platelets

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Chemistry

Background:

• Controlling nanocrystal shape is key to tuning their nanoscale properties.
• Shape control in plasmonic doped semiconductor nanocrystals is less explored than in other nanomaterials.

Purpose of the Study:

• To achieve precise shape control in cesium tungsten oxide (CsWO_3-δ) nanocrystals.
• To explore the relationship between nanocrystal shape and their optical properties, specifically localized surface plasmon resonance (LSPR).

Main Methods:

• Utilized continuous injection synthesis combined with precursor-mediated facet-selective growth.
• Investigated the effect of precursor injection rate and halide ions on nanocrystal anisotropic growth.
• Employed computational simulations to analyze shape-dependent optical properties.

Main Results:

• Achieved exquisite shape control of CsWO_3-δ nanocrystals by modulating precursor injection rate and using halide ions.
• Demonstrated that anisotropic growth is influenced by intrinsic material structure and facet-specific reaction kinetics.
• Tuned LSPR spectra across the near- and mid-infrared regions by systematically varying nanocrystal shape.

Conclusions:

• Developed a robust methodology for shape control in structurally anisotropic nanocrystals.
• Provided theoretical insights into the tunable LSPR properties of heavily doped plasmonic semiconductor systems.
• Highlighted the importance of precursor kinetics and surface passivation for controlling nanocrystal morphology and optical response.