Selective gas sensing by graphene

Graphene might become an ultimate medium for sensing applications, enabling gas and vapor detection with high sensitivity. However, changes in graphene resistivity under the gas exposure might be quite similar for different gases, making the sensing selectivity to be one of the key barriers to overcome. In this paper, we report on using low frequency noise to define the new characteristic parameters, which, in combination with the resistance change, form a unique signature of a gas. The noise measurements can be also used in combination with evaluating “memory step” effect in graphene under gas exposure. (The “memory step” is an abrupt change of the current near zero gate bias at elevated temperatures T > 500 K in graphene transistors.) The “memory step” changes in graphene under gas exposure can be used for high-temperature gas sensors.