Production and Characterization of Topological Insulators

Topological insulators (TIs) represent a novel category of material whose bulk insulates, but whose surface conducts. The ability to produce topological insulators would be of great interest, because electron states can cross the insulating band gap, as well as surface conduction and spin-locking properties [1]. Bismuth selenide (Bi2Se3) is one of the best candidates for three dimensional (3D) TIs. Our project focuses on developing a method to produce undoped and doped Bi2Se3 via vaporliquid-solid (VLS) deposition. Upon examination with a scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD), we found that both nanoribbons and nanowires about 5 μm in length formed; the doped sample with 61.4% selenium, 33.30% bismuth, 5.66% antimony by atomic percentage, and the undoped sample with 61.62% selenium and 38.38% bismuth. Being able to produce these doped and undoped topological insulators opens up exciting new avenues of research into their properties and possible applications.