Impact of Substrates on Graphene Sensors

We have measured desorption of atomic hydrogen from graphene devices on hexagonal boron nitride and compared to our results from graphene devices on silicon oxide using transport measurements in ultra high vacuum environment. We found that atomic hydrogen desorbed at much narrower range of temperatures on hexagonal boron nitride, indicating that chemical interaction was more uniform on hexagonal boron nitride. Our results indicated that hBN could significantly reduce the variability in interaction energies of chemical species on graphene and, as a result, it could be a better substrate for graphene-based chemical sensors.