Fabrication of graphene-based sensor for exposure to different chemicals.

Opto-chemical sensors are the most significant type of sensors that are widely used to detect a variety of volatile organic compounds and chemicals. This research work demonstrates the fabrication and characterization of an opto-chemical sensor based on a graphene thin film. A 300 nm graphene thin film was deposited on clean glass with the help of RF magnetron sputtering. The structure, surface and quality of the graphene thin film were characterized using XRD, SEM and Raman spectroscopy. For optical characterization, the thin film was exposed to IPA, acetone and toluene (separately) for five, ten and fifteen minutes. The optical transmission was then observed via UV-NIR spectroscopy in the near-infrared range (900 to 1450 nm). The thin film of graphene has expressed a sharp response time and recovery time with high sensitivity for each chemical. However, by comparing the output of the graphene thin film in response to each chemical, it was observed that graphene thin film has a better transmission and sensing rate for exposure to toluene.