Novel technique used to study graphene’s response to air

A group of scientists from NPL, Chalmers University of Technology and the US Naval Research Laboratory have used a novel technique to examine the effects of ambient air on graphene in a controlled environment, in order to characterize its response. As graphene is sensitive to a wide variety of chemicals, it is vital for graphene-based sensors to differentiate between the changes that are caused by the target gas and those caused by the natural environment.

The researchers investigated the effects of nitrogen, oxygen, water vapor and nitrogen dioxide (in concentrations typically present in ambient air) on epitaxial graphene inside a controlled environmental chamber. All measurements were taken at NPL by applying Kelvin probe force microscopy whilst simultaneously performing transport (resistance) measurements. This novel combination gave researchers the unique ability to connect the local and global electronic properties together, a task that has proven to be difficult in the past.