Study of a Platinum (Pt) Nanoparticle (NP)/Vanadium Pentoxide (V2O5) Thin Film-Based Ammonia Gas Sensor

A new and interesting ammonia (NH3) gas sensor, based on incorporating a radio frequency(RF) sputtered vanadium pentoxide (V2O5) thin film and thermal evaporated platinum (Pt) nanoparticles (NPs), is fabricated and studied herein. The studied Pt NP/V2O5 device demonstrates abnormal p-type conductive behavior, presumably caused by the presence of an inversion (hole) layer on the surface of the n-type V2O5 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 SR of 83.2% under 1000 ppm NH3/air gas and a very low detecting level of 100 ppb NH3/air with a relatively fast sensing speed are obtained at the optimum temperature of 300 degrees 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/V2O5 thin film structure provides potential for high-performance ammonia sensing applications.