Beyond Noble Metals: ZrN-Based Plasmonic Refractive Index Sensor with T-Shaped Cavity

A plasmonic refractive index sensor featuring ZrN-Insulator-ZrN configuration with a T-shaped cavity and integrated with multiple nanorod defects is designed and analyzed using the finite element method. This structure forms a cavity resonance region, with the nanorod defects enhancing light trapping within the T-shaped cavity. The sensor utilizes Zirconium Nitride (ZrN), a refractory material that outperforms conventional metals by offering superior durability, compatibility and optical properties. A remarkable sensitivity of 2800 nm/RIU is achieved with this sensor which is comparable to the traditional Metal-Insulator-Metal (MIM) arrangements. The proposed sensor with simplicity and ease of fabrication holds great promise for developing highly effective nanoscale sensing devices.