Thickness-dependent bulk properties and weak anti-localization effect in   topological insulator Bi2Se3
  We show that a number of transport properties in topological insulator (TI) Bi2Se3 exhibit striking thickness-dependences over a range of up to five orders of thickness (3 nm - 170 \mu m). Volume carrier density decreased with thickness, presumably due to diffusion-limited formation of selenium vacancies. Mobility increased linearly with thickness in the thin film regime and saturated in the thick limit. The weak anti-localization effect was dominated by a single two-dimensional channel over two decades of thickness. The sublinear thickness-dependence of the phase coherence length suggests the presence of strong coupling between the surface and bulk states. 
Yong Seung Kim, Matthew Brahlek, Namrata Bansal, Eliav Edrey, Gary A.   Kapilevich, Keiko Iida, Makoto Tanimura, Yoichi Hori...
cond-mat.mtrl-sci