Room temperature carbon dioxide gas sensor based on europium oxide with a Kapton film as a flexible substrate

Abstract

The present research explores the fabrication and characterisation of thick films of europium oxide (Eu₂O₃), produced by the screen-printing method onto a Kapton film as a flexible substrate, for carbon dioxide (CO₂) gas sensing at room temperature. Eu₂O₃ has been chosen as sensing material for CO₂ gas due to the unique electrical structure, great sensitivity, and stability, and this study investigates the capability of Eu₂O₃ as gas sensor to interact with various CO₂ concentrations at room temperature. The project aims to develop three Eu₂O₃ thick film sensors (Peu1, Peu2, and Peu3) using screen-printing method. Furthermore, the films gas-sensing characteristics are fully examined utilizing methods such as field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) and Raman spectroscopy. The result obtained from the graph of the I-V measurements of three Eu₂O₃ gas sensors were linear. Peu3 produced the highest response value of 1.53 at concentration of 30 sccm of CO₂. Whereas Peu1 produced response value of 1.66 and 1.97 at concentration of 50 sccm and 70 sccm of CO₂ gas, respectively. In general, Peu1 responded the best to different CO₂ gas concentrations and had the least resistance which was 0.666 GΩ. Redox interactions between CO₂ and Eu³⁺ ions at the Eu₂O₃ surface cause this drop in resistance by increasing the concentration of charge carriers and enhancing the electrical conductivity of the sensor material. These discoveries highlight the tremendous potential of Eu₂O₃ as a sensing material for several industrial applications, including the detection of greenhouse gases.