Enhanced plasmonic performance of TiO2 derived TiN films via gas nitridation

Abstract

This study demonstrates a cost-effective method for planar titanium nitride plasmonic film by nitriding spin-coated TiO₂ in ammonia atmosphere. The effect of nitridation temperature on the structural, morphological, electrical and optical characteristics of the coated films were investigated. The films exhibited high carrier concentration of 1022/cc with significant reduction in resistivity of more than three order of magnitude, indicating the conversion to the nitride phase. Negative permittivity, crucial for plasmonic applications in the visible wavelength region, was verified for wavelengths > 463 nm using Drude-Lorentz model. A three-layer model was employed to verify the material’s plasmonic behaviour. The straightforward fabrication route, which combines spin-coating and ammonia nitridation at 950 °C, offers a new approach for titanium nitride films for plasmonic based gas and biosensing device applications in the visible region. In addition, for fabricating titanium nitride coatings for applications that require abrasion resistance, electrical conductivity, chemical stability, and biocompatibility.