Observation of insulating and metallictype behavior in $\mathrm{Bi}_2\mathrm{Se}_3$ transistor at room temperature

Topological insulators are a new class of electronic materials with promising device applications. In this work, multilayer $\mathrm{Bi}_2\mathrm{Se}_3$ field effect transistors (FETs) are prepared by standard lithography followed by mechanical exfoliation method. Electrical characterization of the FET has been studied at room temperature. We observed both insulating and metallic-type transport behavior when device was gate-biased. Electron-phonon scattering plays a vital role in observing this behavior. We assume that this sort of behavior could be raised from the inherent metallic surface and semiconducting interior bulk properties of $\mathrm{Bi}_2\mathrm{Se}_3$.