The potential of heavily doped n-type silicon in plasmonic sensors

• Published in: Measurement : journal of the International Measurement Confederation Vol. 242; p. 116049
• Main Authors: Joy, Joyonta Das, Rahman, Md. Shakibur, Rahad, Rummanur, Chowdhury, Mehdi Hasan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2025
• Subjects: CMOS-compatible; Doping concentration; Silicon–Insulator–Silicon (SIS); Surface Plasmon Polaritons (SPP); Surface Plasmon Polaritons (SPP); Doping concentration; Silicon–Insulator–Silicon (SIS); CMOS-compatible
• ISSN: 0263-2241
• DOI: 10.1016/j.measurement.2024.116049

In this paper, we introduced a CMOS-compatible H-shaped plasmonic sensor with a silicon–insulator–silicon (SIS) configuration, utilizing highly doped n-type silicon as an alternative to traditional plasmonic materials like silver and gold. By employing precise carrier concentrations, we tuned both the real and imaginary parts of permittivity, enabling the negative real permittivity required for efficient surface plasmon polariton (SPP) propagation. Our findings revealed a significant correlation between silicon doping concentration and sensitivity, highlighting the potential of n-type silicon for advanced plasmonic applications. Through Finite Element Method (FEM) optimization, the sensor achieved a peak sensitivity of 5841.43 nm/RIU and a FOM of 23.8426. The sensor’s capabilities extend to temperature sensing with PDMS and ethanol, blood electrolyte detection for sodium and potassium, chemical detection, and magnetic field sensing. By utilizing minute changes in resonant wavelength through SPPs and SIS structures, our approach underscores n-type silicon’s potential in advancing plasmonic device technology. •The proposed CMOS-compatible plasmonic sensor using highly doped n-type silicon performs better compared to traditional plasmonic materials.•It achieves a maximum sensitivity of 5841.43 nm/RIU, with a Figure of Merit (FOM) of 23.8426 and a Quality Factor (QF) of 23.6512.•Our proposed n-type silicon enhances the sensor performance by reducing optical losses, improving tunability, and minimizing polarization mismatches.•Adjusting the doping concentration allows precise tuning of the sensor’s performance metrics.•The sensor can be promising in various applications: 2.68 nm/°C for PDMS and 2.303 nm/°C for ethanol in temperature sensing, 0.6743 nm/(mg/dL) for sodium and 0.8882 nm/(mg/dL) for potassium in blood electrolytes, 5832 nm/RIU for alcohol detection, and 77.9 pm/Oe for magnetic fields.