Ammonia sensitivity of amorphous carbon film/silicon heterojunctions

摘要

The amorphous carbon film-Si (a-C/Si) junctions have been fabricated by magnetron sputtering. The results show that these junctions have good rectifying properties and high ammonia (NH_3) gas sensitivity. For a given reverse bias voltage, the resistance of the junction can increase by 100 times rapidly when exposed to NH_3 gas. This phenomenon may be attributed to the change of the space charge width of the junction, which is caused by the adsorption of NH_3 gas molecules. This study shows that these a-C/Si junctions have potential application as NH_3 gas detect sensors.