Gas adsorption characteristics of graphene/metal contact structures

摘要

In this paper, the adsorption characteristics of five kinds of graphene/metal contact structures for different types of gases are studied by theoretical calculation. The results show that when graphene/Au and graphene/Pt contact structure adsorb n-type gas, adsorption peaks will appear in the resistivity curve; when p-type gas is adsorbed, the resistivity of the contact structure monotonically decreases, and the resistivity change of graphene/Au is greater than that of graphene/Pt. When graphene/Cu, graphene/Ag and graphene/Al contact structures adsorb gas, the change trend of their resistivity is just opposite to the results of the first two contact structures. The position of the adsorption peak of the contact structure is determined by the Fermi energy difference between graphene and metal (Delta E-F). The smaller Delta E-F is, the closer the adsorption peak is to zero point of the carrier concentration change, and that is to say, the adsorption peak will appear when a small amount of gas is adsorbed. In other words, the smaller Delta E-F is, the greater the gas sensitivity of the contact structure. The research in this paper provides some reference value for the development of novel graphene gas sensor.