Graphene-based flexible NO_2 chemical sensors

摘要

We demonstrated graphene-based flexible NO_2 chemical sensors on polyethylene terephthalate substrate where graphene was grown on Cu-foil by chemical vapor deposition technique. Introduction of NO_2 molecules to graphene caused a rapid increase in the currents due to the charge transfer between NO_2 molecules and graphene under both relaxed and strained conditions. However, the recovery was delayed due to slow desorption of NO_2 molecules from defective sites in graphene. Also, strain in graphene increased the resistance of graphene layer where the change in conductance was reversible. Our graphene-based NO_2 chemical sensors showed a great sensitivity and reproducibility under both strained and relaxed conditions.