Sensing Characteristic Enhancement of Oxygen Plasma Treated Graphene

Graphene has drawn a huge interest as a sensing material due to its outstanding material properties, namely, high surface to volume ratio, high mobility and very low Johnson noise. In this article, we report on the oxygen plasma treatment of single-layer graphene to introduce defects with the goal of enhancing its sensing capabilities. By carefully tuning the plasma power and exposure time, graphene with defect density, exhibiting lower mobility and higher carrier concentration, was obtained while still retaining good electrical properties. The resulting graphene layer responded to NH
₃
gas molecule with much higher sensitivity and much faster response time. The electrical properties of graphene before and after oxygen plasma treatment were investigated and compared with the sensing properties, which indicates plasma treatment can be a simple and effective way to enhance graphene”s sensing abilities.