Fabrication of Gadolinium Oxide-doped Fe2O3-LaFeO3-La2O3 Thick Films by Screen Printing Technique and Their Electrical Properties for Ethanol Gas Sensors

Recently, there have been many researchers who discussed screen printing techniques (SPT) as a good approach to fabricate the thick films for gas sensor applications. In this work, the SPTs were conducted to fabricate the thick films based on gadolinium oxide-doped Fe2O3-LaFeO3-La2O3 that were applied as ethanol gas sensors. The crystal and morphological structures were investigated using x-ray diffraction and scanning electron microscopy, respectively. It shows that there are three phases of the crystal structure of gadolinium oxide-doped Fe2O3-LaFeO3-La2O3 i.e., rhombohedral, orthorhombic, and hexagonal. The morphological structure shows an average particle size of about 0.61 μm. Furthermore, the electrical properties measurements were explored to ensure the performance of thick films in detecting the ethanol gases. Th measurements were conducted in the range of temperature of about 310 ∘C to 325 ∘C and in the various ethanol gas containing, it is 0 ppm, 100 ppm, 200 ppm, and 300 ppm. This result showed that the highest response of thick films in the existence of ethanol gases (300 ppm) is 427 with an optimum temperature of 319 ∘C. It is also confirmed that SPT has an excellent approach in thick film fabrication to produce gas sensor devices with good performance. Keywords: fabrication, gadolinium oxide, doped, thick films, screen printing, electrical properties, ethanol, sensors