The electronic and optical properties of the sulvanite compounds: a many-body perturbation and time-dependent density functional theory study
2018 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 30, no 3, article id 035502Article in journal (Refereed) Published
Abstract [en]
We have studied, by means of first-principles calculations, the electronic and optical properties of the sulvanite family: Cu3MX4 (M = V, Nb, Ta and X = S, Se), which, due to its broad range of gaps and chemical stability, have emerged as promising materials for technological applications such as photovoltaics and transparent conductivity. To address the reliability of those properties we have used semi-local and hybrid functionals (PBEsol, HSE06), many-body perturbation theory (G(0)W(0) approximation and Bethe-Salpeter equation), and time-dependent density functional theory (revised bootstrap kernel) to calculate the quasi-particle dispersion relation, band gaps, the imaginary part of the macroscopic dielectric function and the absorption coefficient. The calculated valence band maximum and the conduction band minimum are located at the R and X-points, respectively. The calculated gaps using PBEsol are between 0.81 and 1.88 eV, with HSE06 into 1.73 and 2.94 eV, whereas the G(0)W(0) values fall into the 1.91-3.19 eV range. The calculated dielectric functions and absorption coefficients show that all these compounds present continuous excitonic features when the Bethe-Salpeter equation is used. Contrarily, the revised bootstrap kernel is incapable of describing the excitonic spectra. The calculated optical spectra show that Cu3VS4 and Cu3MSe4 have good absorption in the visible, whereas Cu3NbS4 and Cu3TaS4 have it on the near ultraviolet.
Place, publisher, year, edition, pages
Institute of Physics (IOP), 2018. Vol. 30, no 3, article id 035502
Keywords [en]
semiconductors, sulvanite, optical properties, GW, TDDFT, BSE, excitons
National Category
Condensed Matter Physics
Research subject
Physics
Identifiers
URN: urn:nbn:se:kau:diva-80956DOI: 10.1088/1361-648X/aa9debISI: 000418114500001PubMedID: 29182517OAI: oai:DiVA.org:kau-80956DiVA, id: diva2:1478280
Funder
Swedish Research CouncilSwedish Energy AgencyStandUp2020-10-212020-10-212022-05-23Bibliographically approved