Recently, the research group of Professor Yang Liangbao from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, enhances localized surface plasmon resonance (LSPR) by studying Cu₂O₁₋ₓ superlattices with oxygen vacancies, offering new insights into vacancy doping in semiconductors and LSPR induction in metal oxide nanoparticles.
The relevant findings have been published in Nano Letters.
Localized Surface Plasmon Resonance (LSPR) refers to the collective oscillation of free electrons in metal nanoparticles, resulting in a resonance phenomenon that absorbs and scatters light at specific wavelengths. This unique optical property enables LSPR to be applied in various fields such as biosensing, where it enhances detection sensitivity, and in photocatalysis, where it facilitates light-driven chemical reactions. Additionally, LSPR-based materials show promise in color tuning and energy harvesting applications.
The team has long focused on the study of LSPR enhancement. Building on this foundation, they advanced their research by investigating the potential of Cu₂O₁₋ₓ superlattices in boosting LSPR effects. Through a series of carefully designed experiments, they successfully synthesized Cu₂O₁₋ₓ superlattice structures that were rich in oxygen vacancies, and observed a remarkable enhancement in LSPR.
The study revealed that these oxygen vacancies played a crucial role in increasing the carrier concentration and modifying the material' s electronic band structure. Specifically, the oxygen vacancies caused the valence band edge to shift closer to the Fermi level, while narrowing the band gap. This structural alteration induced intraband transitions, generating powerful LSPR modes and significantly amplifying the electromagnetic field. As a result, the material showed outstanding performance in Surface-Enhanced Raman Spectroscopy (SERS) detection.
This research provides a novel perspective on vacancy doping in semiconductors and opens new avenues for inducing LSPR in metal oxide nanoparticles.
Characterization of oxygen vacancy properties generated by Cu2O1-x superlattice structures and corresponding disordered structures (Image by YAO Chang)
