Insulating behavior in ultra-thin bismuth selenide field effect transistors

TL;DR

This study investigates the insulating behavior of ultrathin Bi2Se3 topological insulator FETs, revealing their n-type conduction, gate-tunable OFF state, and thermally activated conductance with significant energy barriers.

Contribution

It demonstrates the insulating behavior and energy barrier characteristics of ultrathin Bi2Se3 FETs, providing insights into their electronic properties at nanoscale thicknesses.

Findings

Ultrathin Bi2Se3 FETs are n-type with a clear OFF state.

Conductance shows activated temperature dependence.

Energy barriers up to 250 meV were observed.

Abstract

Ultrathin (~3 quintuple layer) field-effect transistors (FETs) of topological insulator Bi2Se3 are prepared by mechanical exfoliation on 300nm SiO2/Si susbtrates. Temperature- and gate-voltage dependent conductance measurements show that ultrathin Bi2Se3 FETs are n-type, and have a clear OFF state at negative gate voltage, with activated temperature-dependent conductance and energy barriers up to 250 meV.