Quick surface adsorption and sensing of ammonia at room temperature by In2S3 thin films

Here, we report a highly sensitive and selective ammonia sensor based on In2S3 thin films. In2S3 was deposited by sulfurization of indium films. The adsorbed oxygen species on the surface of the sample (observed from X-ray Photoelectron Spectroscopy) react quickly with the testing gas and the response is observed in terms of the change in resistance of the device. The device is tested for concentrations of ammonia as low as 10 ppm. It shows a stable, uniform response with response and recovery time of 4.2 s and 1.2 s respectively. The results imply the potential use of In2S3 thin films as a promising material for selective sensing of ammonia at room temperature.