The role of doping and vacancies in the structural and electronic properties of TeGeX (X=Sb, Sn, and vacancies) alloys: A first-principles study

S. LIZETH CHUCCHUCAN G.; L. A. ERRICO; A. M MUDARRA NAVARRO

Workshop; X Workshop on Novel Methods for Electronic Structure Calculations; 2023

Te-based chalcogenide materials have been found toexhibit very outstanding characteristics for use in thermoelectric andphase-change memories    applications. For this reason, many efforts have been made to the chemical compositionand the electronic properties of these compounds.In this work we study the structural, electronic andthermoelectric properties of TeGeX (X: Sb, Sn) and the role played by the Gevacancies in the origin of these properties by means of Density FunctionalTheory based first principles methods. Calculations were performed usingthe full-potential linearized augmented plane waves method (FP-LAPW) methodconsidering different vacancy and dopant distributions and concentrations. Theoreticalmodelling shows that Sn replaces Ge atoms and that Ge vacancies formed. Thereis no preferential distribution of dopants or vacancies in the Ge sublattice.The obtained results obtained for the structural and electronic properties andthe hyperfine parameters at the Sn sites are compared with experimental resultsobtained by X-ray diffraction, 119Sn Mössbauer spectroscopy andother characterization techniques to achieve a better characterization of thesystem under study.