Self-Assembled Dichroic Plasmonic Nitride Nanostructures with Broken Centrosymmetry for Second-Harmonic Generation

TiN and ZrN are emerging as important alternative plasmonic materials. In addition to their well-known assets, they can incorporate point defects that break the centrosymmetry of their cubic crystal structure, making them promising candidates as nonlinear optical materials, especially for second-harmonic generation (SHG). Their refractory character and chemical stability have been obstacles for the bottom-up fabrication of TiN and ZrN nanostructures so far. In this work, it is shown that highly directional dichroic nanostructures of TiN and ZrN may be indeed grown by self-assembly using glancing angle deposition on periodic rippled dielectric surfaces. The produced nitride nanostructures exhibit point defects and exceptional photothermal durability. These nanostructures exhibit strong SHG response when probed by a near-infrared laser. It is shown that SHG is strongly associated with the near-field enhancement due to localized surface plasmon resonance of the nanostructures. Given that such nanostructures can endure extremely high electric fields, they are expected to be able to emit massive SHG signals and be applied in laser technology as optical components such as polarizers and SHG emitters.

Automated summary

TiN and ZrN are emerging as important alternative plasmonic materials with potential applications as nonlinear optical materials, especially for second-harmonic generation (SHG). Highly directional dichroic nanostructures of TiN and ZrN can be grown by self-assembly using glancing angle deposition on periodic rippled dielectric surfaces, showing strong SHG response and exceptional photothermal durability due to the incorporation of point defects. These nanostructures, with strong SHG response associated with near-field enhancement from localized surface plasmon resonance, are expected to be applied in laser technology as optical components such as polarizers and SHG emitters.