Hydrogen sensors based on metal-insulator-semiconductor structures with a layer of a proton-conducting solid electrolyte

Polyoxometalates: formation, structures, principal properties, main deposition methods and application in sensing

“…293 The detection of other gases such as H 2 , CO and vapors of organic solvents with deposited POMs has also been the subject of various investigations. For example, Vasiliev et al 294 reported that the presence of POMs in proton-conducting solid electrolytes like Naon, zirconium hydrophosphate and etheried polyvinyl alcohol yields an H 2 sensor with improved characteristics. On the other hand, CO gas can be measured with POM based silicon immobilized in sol-gel supports with reasonable sensitivities and detection limits that may reach as low as 5 ppm CO. 192 Finally, saturated vapors of organic solvents including acetone, benzene, xylene, amyl alcohol, ethyl alcohol, isobutyl alcohol, isopropyl alcohol, toluene and chloroform can be detected by sensors constructed from PW 12 O 40 3À encapsulated in polymers like polyaniline, polypyrrole and poly-3-methylthiophene.…”

High-Energy X-ray Photoemission and Structural Study of Ultrapure LaF3 Superionic Conductor Thin Films on Si

“…In this work, we studied the growth, morphology, and chemical composition of highly ordered LaF 3 epitaxial layers on silicon by high-energy X-ray photoelectron spectroscopy (HAXPES) flanked by conventional XPS, atomic force microscopy (AFM), and reflection high-energy electron diffraction (RHEED). Indeed, LaF 3 thin films have been investigated quite extensively in the literature. − ,,,− Different methods of growth were applied, including sol–gel technique, chemical vapor deposition, vacuum thermal deposition, and molecular beam epitaxy (MBE). Defects, either vacancies or impurities, play a fundamental role in ion conduction, but they also influence optical properties.…”

“…Lanthanum fluoride (LaF 3 ) is a promising material, both for fundamental studies and for technology. It is classified as a superionic compound that is appealing for fabrication of all-solid-state electrolytes. − In this respect, it has been successfully applied as active and transport material in a variety of sensing devices, in both liquid and gaseous environments − and in metal–insulator–semiconductor (MIS) systems . Moreover, it presents a high damage resistance to UV irradiation, making it suitable for optical coatings in UV laser applications. , In addition, it also shows good infrared transmission for applications in photonic devices.…”

“…2−5 In this respect, it has been successfully applied as active and transport material in a variety of sensing devices, in both liquid and gaseous environments 6−10 and in metal−insulator−semiconductor (MIS) systems. 11 Moreover, it presents a high damage resistance to UV irradiation, making it suitable for optical coatings in UV laser applications. 12,13 In addition, it also shows good infrared transmission 14 for applications in photonic devices.…”