Fig. 3. Microscopic staggered defects in liquid-Te assisted growth.

a HAADF-STEM image, (b) the corresponding inverse Fourier transform image and (c, d) GPA results along xx and yy direction of the P-type Bi_0.4Sb_1.6Te_3+x (x = 0.17) sample. a shows tense of staggerd layers structure among the lattice, and the symbol ⊥ in (b) indicates dislocations and the black circle represents the termination point of the staggered stacking faults, showing tense of staggered layers structure among the lattice; (e) high-magnification image of the staggerd layers structure; (f) the image intensity along the arrow 1 and 2 in the enlarged high-magnification TEM image (g) of the single typical staggered layers; (h) the atomic configuration map of the single typical staggered layers in (g); (i) the formation energy of typical defects in Bi₂Te₃ and Sb₂Te₃ compounds under different Te chemical potential; (j) the sketch map of staggered layers generation mechanism.