High magnetoresistance at room temperature in p-i-n graphene nanoribbons due to band-to-band tunneling effects

Abstract

A large magnetoresistance effect is obtained at roomerature by using p-i-n armchair-graphene-nanoribbon (GNR) heterostructures. The key advantage is the virtual elimination of thermal currents due to the presence of band gaps in the contacts. The current at B 0 T is greatly decreased while the current at B 0 T is relatively large due to the band-to-band tunneling effects, resulting in a high magnetoresistance ratio, even at roomerature. Moreover, we explore the effects of edge-roughness, length, and width of GNR channels on device performance. An increase in edge-roughness and channel length enhances the magnetoresistance ratio while increased channel width can reduce the operating bias. © 2011 American Institute of Physics.