Effect of oxide-electrode interface on dilute NO2 sensing properties of WO3 thin film nanosensors

The WO3 thin film nanosensors have been fabricated by dropping and calcination of H2WO4 suspension onto Au nano-gap electrode (100 nm of gap-size and 10 pm in width), which was fabricated by means of MEMS (Micro Electro-Mechanical Systems) techniques, photolithography and FIB. The amount of WO3-electrode interface was controlled by changing amount Of WO3 grains packed in the nano-gap electrode. The sensitivity to dilute NO2 was increased with increasing amount of interface, suggesting the importance of oxide-electrode interface in NO2 sensing. Further, the response behavior was affected by the amount of WO3 grains packed in nano-gap electrode.