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

A new and interesting ammonia (NH
₃
) gas sensor, based on incorporating a radio frequency (RF) sputtered vanadium pentoxide (V
₂
O
₅
) thin film and thermal evaporated platinum (Pt) nanoparticles (NPs), is fabricated and studied herein. The studied Pt NP/V
₂
O
₅
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
₂
O
₅
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
_R
of 83.2% under 1000 ppm NH
₃
/air gas and a very low detecting level of 100 ppb NH
₃
/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
₂
O
₅
thin film structure provides potential for high-performance ammonia sensing applications.