Fig. 1. Materials characterization of Bi₂Te₃ NPs.

a Schematic illustration of growth mechanism for Bi₂Te₃ NPs. b AFM image of a Bi₂Te₃ NP and the corresponding height/width profile along the solid line across the nanoplate. c SEM and TEM images (inset) of the hexagonal Bi₂Te₃ NPs. d HRTEM image of Bi₂Te₃ sample and the corresponding SAED image with bright hexagonally symmetric spots. e Statistic of the size distribution of Bi₂Te₃ NPs by AFM analysis. f XRD pattern of the fabricated Bi₂Te₃ NPs. g High-resolution XPS spectra of Bi 4f and Te 3d region, respectively. h Raman spectra were collected from stochastic sites on an individual Bi₂Te₃ NP. Source data are provided as a Source Data file.