Study of a Platinum (Pt) Nanoparticle (NP)/Vanadium Pentoxide (V<sub>2</sub>O<sub>5</sub>) Thin Film-Based Ammonia Gas Sensor
Yen-Lin Pan, Wen-Chau Liu
Abstract
A new and interesting ammonia (NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) gas sensor, based on incorporating a radio frequency (RF) sputtered vanadium pentoxide (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> ) thin film and thermal evaporated platinum (Pt) nanoparticles (NPs), is fabricated and studied herein. The studied Pt NP/V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> device demonstrates abnormal p-type conductive behavior, presumably caused by the presence of an inversion (hole) layer on the surface of the n-type V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> thin film. The employment of Pt NPs effectively enhances the specific surface area, catalytic activity, and related ammonia sensing properties. Experimentally, a high sensing response ratio for S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</sub> of 83.2% under 1000 ppm NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /air gas and a very low detecting level of 100 ppb NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /air with a relatively fast sensing speed are obtained at the optimum temperature of 300 °C. The studied device also shows the advantages of a simple structure, good selectivity, easy fabrication, and stable and reversible sensing performance. Therefore, the studied Pt NP/V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> thin film structure provides potential for high-performance ammonia sensing applications.