Ambipolar charge injection and transport of few-layer topological insulator Bi_2Te_3 and Bi_2Se_3 nanoplates

摘要

We report the electrostatic properties of few-layer Bi_2Te_3 and Bi_2Se_3 nanoplates (NPs) grown on 300 nm SiO_2Si substrate. Electrons and holes are locally injected in Bi_2Te_3 and Bi_2Se_3 nanoplates by the apex of an atomic force microscope tip. Both carriers are delocalized uniformly over the whole nanoplate. The electrostatic property of topological insulator Bi_2Te_3 and Bi_2Se_3 nanoplates after charge injection is characterized by Kelvin probe force microscopy under ambient environment and exhibits an ambipolar surface potential behavior. These results provide insight into the electronic properties of topological insulators at the nanometer scale.