Topological insulators are unique electronic materials with insulating interiors but robust metallic surfaces. Device applications exploiting their remarkable properties, such as surface conduction of helical Dirac electrons, have so far been hampered by the difficulty to tune the Fermi level inside the band gap. Here we show experimentally that single-crystal nanowires of the topological insulator Bi2Se3 can be used as the conduction channel in high-performance field effect transistor (FET), a basic building block of electronic circuits. Its current-voltage characteristics are superior to many of those reported for nanowire-FETs based on conventional semiconductors, including sharp turn-on, cutoff current below the measurement threshold of 10-14 A, large On/Off current ratio (~ 108), and well-saturated, strong inversion-mode output current. The metallic electron transport at the surface, with effective mobility on the order of 200 cm2V-1s-1 to 1300 cm2V-1s-1, and bulk conduction, with activation energy close to band gap of bulk Bi2Se3, can be effectively separated and tuned by field effect at a small gate voltage. This opens up a suite of potential applications in nanoelectronics and spintronics.
Citation: Nature Nanotechnology
Pub Type: Journals
nanoelectronics, topological insulator, transistor, Bi2Se3, nanowire, Beyond-CMOS