Mehta, S.Vankalkunti, S.Kachhap, P.K.Gautam, P.R.Singh, M.2026-02-042023Materials Science in Semiconductor Processing, 2023, 165, , pp. -13698001https://doi.org/10.1016/j.mssp.2023.107687https://idr.nitk.ac.in/handle/123456789/21702This work proposes a photonic crystal refractive-index sensor for detecting volatile organic compounds (VOC). Two sensor designs are analyzed with Y-splitter photonic crystal waveguide using the finite-difference time-domain (FDTD) method. Also, simultaneous monitoring of two different analytes is possible across the arms of the Y-splitter. The porous silicon (p-Si) rods with a porosity of 25% are used to create a variable refractive index sensing region, which induces a relative shift in the resonant wavelength of the traveling mode. The response at the output ports is monitored in terms of transmittance power versus wavelength plot. The numerical simulations confirm ∼195.83 nm/RIU sensitivity and ∼24.482 RIU−1 figure-of-merit in the presence of hazardous alcohols. © 2023 Elsevier LtdEnergy gapFinite difference time domain methodNanorodsPhotonic band gapRefractive indexVolatile organic compoundsAnalytesCrystal waveguidesNano-rodsPhotonic bandgap (PBG)Refractive index sensorSensitivity improvementsSensor designsSilicon rodsSimultaneous monitoringY splitterPorous silicon