Abstract
In this work, we have coated 0, 1, 3, and 5 wt% of Erbium (Er)-doped tin oxide (SnO2) films on glass using a simple nebulizer spray pyrolysis method to make an ammonia vapor sensor with remarkable sensitivity. X-ray diffraction, Atomic force microscopy, Ultraviolet-visible spectroscopy and photoluminescence methods were employed to inspect the thin-film samples. Room-temperature ammonia vapor sensing was performed by a computer connected to the homemade gas-sensing system. The results obtained show that Er doping in SnO2 films gradually decreased the crystallite size with an increase of the surface area improving the sensing property of the vapor. A minimum optical band gap (i.e., 3.23 eV) is achieved for 5 wt% Er-doped film. The fabricated Er-doped SnO2 gas sensor showed response/recovery time highly dependent on dopant concentration. The Er concentration of 5 wt% doped SnO2 thin film showed maximum sensitivity of 91%, fast response, and recovery time of 29 and 7 s, respectively, due to high surface to volume ratio.