Eur. Phys. J. Appl. Phys. 99, 19 (2024)
https://doi.org/10.1051/epjap/2024240081

Original Article

Investigation of a sensitive, selective and cost-effective electrochemical meso-porous silicon based gas sensor for NO₂ detection at room temperature

¹ Laboratoire de Nanomatériaux et Systèmes pour Energies Renouvelables, Centre de Recherches et des Technologies de l'Energie, Technopôle de Borj-Cédria, BP 95 Hammam-Lif, Tunis, Tunisie
² Laboratoire de Photovoltaïque, Centre de Recherches et des Technologies de l'Energie, Technopôle de Borj-Cédria, BP 95 Hammam-Lif, Tunis, Tunisie
³ Aix Marseille Univ, CNRS, IM2NP, AMUTech, Marseille, France
⁴ Aix Marseille Univ, CNRS, CINaM, AMUTech, Marseille, France

^* e-mail: rabia.benabderrahmane@gmail.com

Received: 2 May 2024
Accepted: 12 June 2024
Published online: 4 September 2024

Abstract

This work presents a nitrogen dioxide (NO₂) gas sensor based on porous silicon with improved sensitivity, selectivity, and cost-efficiency. Porous silicon is being researched as an alternative material for gas sensors operating at room temperature (RT), making it suited for low-consumption applications. Meso-porous silicon (meso-PS) films were prepared on p+ type Si (100) using an electrochemical method for NO₂ gas sensing. Morphology, structural and optical properties of meso-PS films were investigated using scanning electron microscope (SEM), X-ray diffractometer (XRD), and UV-Vis spectroscopy. The gas sensing response of meso-PS samples was performed at RT with top parallel Al electrodes in the range of 4–10 ppm of NO₂ gas. The tested sensor showed high normalized response (R_air/R_gas = 40 for 4 ppm to 100 for 10 ppm) thanks to its high surface/volume ratio, good repeatability and reversibility, fast response (40 s) and recovery times (18 s), and good selectivity for NO₂ versus NH₃, O₃ and CO. All these performances obtained at RT are encouraging for low-power devices.