(color online) (a)–(c) SEM image of Bi₂Te₃ film samples formed with various Bi₂Te₃ nanoplates. (d) Number of nanoplate grains per area versus the average mobility of the film. (e)–(g) Magneto-resistance [R(B)−R(0)]/R(0) as a function of magnetic field at various temperatures for three different samples. (h) The relationship between mobility and [R(14T)−R(0)]/R(B = 0) for various samples with different granularities. Modified from Wang et al., Ref. [64].