Comparative ab initio study of the electronic structure and thermoelectric properties of tin selenide with electron and hole conductivity

• Published in: Physica. B, Condensed matter Vol. 695; p. 416529
• Main Authors: Zhukov, V.P., Chulkov, E.V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2024
• Subjects: Boltzmann-onzager theory; Figure-of-merit; First-principles calculations; PAW method; Power function; Tin selenide; Tin selenide; First-principles calculations; PAW method; Power function; Boltzmann-onzager theory; Figure-of-merit
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2024.416529

Ab initio calculations of the electronic structure and thermoelectric characteristics of low- and high-temperature phases of tin selenide, SnSe, with electronic and hole conductivity have been performed. It is shown that the calculations of thermoelectric properties on the basis of the Boltzmann-Onzager theory with consideration of carrier scattering on optical phonons lead to results in good agreement with experimental data. At temperatures below 600 K the modeling correctly reproduces the increased values of the figure-of-merit of electron-doped SnSe in comparison with almost stoichiometric or hole-doped selenide calculations. We explain anomalously high figure-of-merit values of the non-doped selenide at T > 600 K by the hole concentration increase due to oxidation of SnSe or the appearance of vacancies in the tin sublattice. For all the considered variants, i.e. for electron-doped low-temperature and high-temperature phases and low-temperature hole-doped phase, the modeling predicts the absence of figure-of-merit increase at exceeding some limiting concentration of current carriers.