Weak antilocalization to weak localization transition in Bi2Se3 films on graphene

Abstract Magneto-transport properties were studied on thin films of a 3D topological insulator (TI) Bi 2 Se 3 grown on graphene (Gr) by physical vapor deposition . It was shown that the main contribution to the conductance is from the bulk states, whereas magnetoresistance is determined by both surface and bulk channels. The input of the charge transport over the surface states in the Si/SiO 2/Gr/Bi 2 Se 3 structure reveals itself in the weak antilocalization effect. The transition from a weak antilocalization to a weak localization is observed with decreasing the film thickness. The band bending on both interfaces makes it possible to explain the contribution to a weak antilocalization from different surfaces at different TI film thicknesses.