Plasmonic-Photonic Hybrid Modes Excited on a Titanium Nitride Nanoparticle Array in the Visible Region

Conventionally used plasmonic materials generally have low thermal stability, low chemical durability (except gold), and are incompatible with complementary metal-oxide semiconductor processes. However, titanium nitride (TiN), an emerging plasmonic material, possesses gold -like optical properties, but displays relatively large ohmic losses. We fabricated a periodic array of TiN nanoparticles to effectively reduce these losses by coupling the localized surface plasmon resonance with light diffraction. The height of the nanoparticle and the periodicity of the array were designed to match the excitation conditions of both the localized surface plasmon resonance and light diffraction. As a result, the array supported a plasmonic photonic hybrid mode in the visible region. For the loss mitigation effect to be assessed, photoluminescence (PL) from the light emitting layer on the array was measured. The PL intensity was larger than that from the same layer on a TiN thin film, demonstrating reduced loss. The angular and spectral profiles of the PL could be controlled by the hybrid mode. Our results thus pave the way toward plasmonic devices that can be fabricated using traditional complementary metal oxide semiconductor processes.