Hydrogen Sensing Properties of the Pt Caped Ag Doped Gallium Oxide Nanomaterials

A thin film of gallium oxide possesses the characteristics of an n-type semiconductor and remains stable at an elevated temperature. In a thin film, the concentration of hydrogen influences the resistivity of Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>. A hydrogen sensor was constructed according to this design principle. With Ar as the sputtering gas, RF magnetron sputtering was used to deposit a gallium oxide film from the metal Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> target onto the alumina substrate. Thin coatings of Pt caped Ag doped Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> that conduct electricity and are hydrogen-sensitive at temperatures of 400°C were manufactured using a sputtering process. A bulk effect independent of the film thickness determines their sensitivity to stable hydrogen. The duration of the responses is measured in seconds. Pt caped Ag doped Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> thin films have the potential to function as catalytically inactive hydrogen sensors when temperature compensation is appropriate.