Thickness-dependent magnetoresistance of Sb2Te3 nanoflakes and weak antilocalization effect

Magnetoresistance of single crystalline Sb2Te3 topological insulator nanoflakes of different thickness has been studied in magnetic fields up to 9 T at temperatures of 2K and 300K. The obtained values of magnetoresistance demonstrate strong dependence on thickness of the nanoflakes. The behavior of the magnetoresistance was attributed to the behavior of the mobility of charge carriers which in its turn depends on thickness and temperature of the nanoflakes. The magnetoresistance of the sample with the thickness of 25 nm shows pronounced weak antilocalization effect (inherent for topological insulators) which is the contribution of surface states to the electronic transport. Shubnikov??de Haas oscillations were revealed on the magnetoresistance of the thickest sample with the thickness of 450 nm which is a response of the bulk states on applied magnetic field.