Highly sensitive temperature sensor based on tunable stoichiometric alternative plasmonic material using multiple thermo-responsive analytes

This study presents a CMOS-compatible plasmonic sensor designed for temperature detection across multiple thermo-responsive analytes with ultra-high sensitivity. Addressing the limitations of traditional plasmonic materials, we explore yttrium-doped titanium nitride (TiN) as an alternative, offering enhanced stability, thermal durability, and compatibility with CMOS fabrication processes. The sensor, featuring a double-ring connected resonator, achieves a refractive index sensitivity of 3863.54 nm/RIU and a temperature sensitivity of 2.44735 nm/°C in a chloroform-based medium. By optimizing yttrium doping levels, we balance plasmonic tunability with material stability, as evidenced by dielectric permittivity and SPPs parameters and found that the ratio of Ti and Y having 91%:9% exhibits higher sensitivity than the others (63%:37%, 79%:21%, 85%:15%). Comparative analysis across dielectric environments highlights the sensor’s adaptability and high sensitivity in different thermo-responsive dielectric media. Thus, this work advances plasmonic sensor technology for precise temperature sensing applications.