Gas sensing of tellurium-modified silicon nanowires to ammonia and propylamine

Tellurium nanoparticles with an average diameter of 5 nm were grown on silicon nanowires through a solution method. The gas sensors based on as-prepared material was exposed to ammonia and propylamine and their sensing behavior was investigated in detail, which showed a higher sensitivity than Te film at room temperature. The detection ranges of ammonia and propylamine were 10–400 ppm and 5–25 ppm, with the low detection limits of 196 and 174 ppb, respectively. The response times upon exposure to ammonia and porpylamine were 5 and 15 s and the recovery times were 8 and 6 s, respectively. It was found that the response of the sensor was 208% or 164% when exposing to 400 ppm ammonia or 25 ppm propylamine at the optimal operating temperature. The excellent sensitivity and fast response might be ascribed to the small size of tellurium nanoparticles. Considering the above advantages of tellurium-modified silicon nanowires, they have potential applications as nanosensors.