Band bending and effective index in the engineered Mach–Zehnder interferometer-based electrolytic sensor.

Autor: Mishra, Pawan, Papadovasilakis, Marios, Taha, Ayat, Flores, Raquel, Janeiro, Ricardo, Viegas, Jaime
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Zdroj: Applied Nanoscience; May2023, Vol. 13 Issue 5, p3213-3223, 11p
Abstrakt: We studied a Mach–Zehnder Interferometer (MZI)-based electrolytic sensor on a silicon-on-insulator (SOI) platform. First, the Si waveguide, integrated with the dielectric layer (SiO2) and operating under varying pH, is designed using commercial software Nextnano. The impact of the band bending in the SiO2 integrated with the Si waveguide is presented. Parameters obtained using Nextnano from the designed Si waveguide structure, under varying pH values of electrolytic solutions, were adopted to design an MZI-based electrolytic sensor. We also present a simple strategy for experimental verification of liquid electrolyte's effects on the optical properties of SiO2/p-Si using spectroscopic ellipsometry. Two different schemes of MZI-based electrolytic sensors were numerically investigated using the Finite Difference Eigenmode method. A rib waveguide-based sensor demonstrates increased sensitivity compared to a strip waveguide-based sensor. This work contributes to developing robust and waveguide integrated sensors for applications in next-generation electrolytic and biosensors. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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