Catalyst-free Growth of Single Crystalline Bi2Se3 Nanostructures for Quantum Transport Studies

In this work we report on the growth of single crystalline Bi2Se3 nanostructures (nanoribbons, nanoflakes, and nanowires) by catalyst-free decomposition sublimation in sealed silica ampules. The nanostructures directly grow on Si/SiO2 substrates by a vapor–solid growth mechanism and show high degree of crystallinity with dimensions of >10 μm in length and simultaneously <10 nm in height (nanoribbons). In order to optimize the growth process in a reproducible way, thermodynamic calculations were realized. The high quality of as-grown nanostructures was confirmed by transmission electron microscopy including selected area electron diffraction as well as electrical transport measurements. Our electrical transport data are evidence, on the one hand, of the high crystal quality and efficiency of the synthesis by decomposition sublimation. On the other hand, the catalyst-free approach offers the chance to investigate crystals with high purity and to measure surface state properties.