Controlling the carrier concentration of Bi2Se3 nanoribbons via doping and gating

Bi2Se3 is one of the few materials identified as a topological insulator; hence, many efforts are underway to measure its electric properties. While recent transport studies of Bi2Se3 nanoribbons have provided strong evidence for the existence of surface states, additional measurements are needed to reveal identifying signatures of the topological states such as dissipationless transport or spin polarized current. The main roadblock to these experiments is the high bulk carrier concentration, which masks the effects of the surface states. Here, we present our efforts to reduce the bulk carrier concentration in Bi2Se3 nanoribbons via doping and gating.