High-quality single-crystalline BiSe topological insulator nanowires and nanobelts grown via chemical vapor deposition†

Abstract

BiSe is a layered topological insulator, which has not gained enough attention, while nanoscale topological insulator materials with high surface-to-volume ratio are promising candidates for advanced electronic devices. In this study, we report a facile chemical vapor deposition approach to synthesize high-quality BiSe nanowires and nanobelts, which exhibit the typical electrical transport property of topological insulators. Morphological and microstructural characterizations confirmed that single-crystalline BiSe nanowires and nanobelts with large surface area, near stoichiometric compositions and aspect ratios exceeding 1500 were formed. The growth of the BiSe nanowires and nanobelts was investigated in detail. It was found that appropriate growth temperature enabled optimal morphology, and an Au-catalyst-assisted vapor–liquid–solid mechanism was employed to control the quantity and quality of the products. The linear positive magnetoresistance at 2 K was observed in an individual BiSe nanowire; the results suggested the presence of massless Dirac fermions on the surface and gapless surface states, while a weak antilocalization effect was detected near 0 T magnetic field. This work provides a feasible route to synthesize one-dimensional BiSe nanostructures with well-defined morphology and reveals their intriguing magnetoresistance property.