Core Reconstruction of Dislocations in layered-chalcogenide semiconductors (Bi2X3 - X = Te, Se, and S)*

The interest in the layered chalcogenide family Bi2X3 (X = Te, Se, and S) is due to their
thermoelectric properties and the topology of their electronic structure. Understanding scattering of
electronic carriers and phonons in such materials is crucial for devising strategies to improve their
thermoelectric properties. A crucial step is the identification of the reconstruction patterns in the
core of dislocations in these covalently-bonded systems. In this work, we investigate the single- and
double-period core reconstruction of the 60-degree and the screw dislocations - both with
Burguers vector parallel to the basal plane - in these materials. Issues of dissociation of the 60-
degree and the screw dislocations into 30-degree and 90-degree partial dislocations will also be
discussed.