Substrate-independent catalyst-free synthesis of high-purity Bi_2Se_3 nanostructures

摘要

We describe a catalyst-free vapor-solid synthesis of bismuth selenide (Bi_2Se_3) nanostructures at ambient pressure with H_2 as carrier gas. The nanostructures were synthesized on glass, silicon, and mica substrates and the method yields a variety of nanostructures: nanowires, nanoribbons, nanoplatelets, and nanoflakes. The materials' analysis shows high chemical purity in all cases, without sacrificing the crystalline structure of Bi_2Se_3. Low-temperature measurements of the nanostructures indicate contributions from the surface states with a tunable carrier density. Samples synthesized on flexible mica substrates show no significant change in resistance upon bending, indicating robustness of as-grown Bi_2Se_3 nanostructures and their suitability for device applications.