“…6,7,[14][15][16][17] In particular, the nature of the carrier type was found to be strongly dependent on intrinsic point defects, leading to intensive efforts to understand the role of these defects in variation of the thermoelectric properties. 5,7,10,[14][15][16][18][19][20][21][22][23] Consistent with the general behavior of A V 2 B V I 3 semiconductors, Bi 2 Te 3 crystals grown from stoichiometric melts show an enhanced overstoichiometry of the group-V element. Excess Bi can be accommodated in single-crystalline Bi 2 Te 3 by means of the following point-defect mechanisms: (i) antisite (AS) defects, i.e., by replacement of Te atoms on a Te sublattice by Bi atoms, denoted as Bi Te ; (ii) by additional regular Bi sites, i.e., Bi Bi , accompanied by the creation of vacancies on a Te sublattice, denoted as V Te ; (iii) by interstitial Bi atoms.…”