DFT simulations of functional chalcogenide semiconductors


A.V. Kolobov


Herzen State Pedagogical University of Russia



Abstract:

Chalcogenides, i.e. materials that contain S, Se, and/or Te, were the materials, where semiconductor properties were first observed, for example the specific temperature dependence of conductivity (by M. Faraday in 1833) and photoconductivity (by W. Smith in 1874). The interest in chalcogenides was renewed with the discovery of amorphous chalcogenide semiconductors (B.T. Kolomiets, 1955). In recent years, chalcogenides attract great attention as phase-change materials widely used in memory cells [1], topological insulators, and two-dimensional (2D) semiconductors [2]. In this talk, I shall present several examples of how DFT simulations helped understand fundamental properties of different classes of functional chalcogenides, in particular, the origin of the property contrast in phase-change alloys [3] and interfacial phase-change memories [4,5], the role of electronic excitation in the phase-change process [6], the formation (or not) of the Dirac cones on surfaces of topological insulators [7], atomic reordering accompanied by a huge property contrast in ultrathin chalcogenides [8] and a photo-induced semiconductor-metal transition in monolayers of 2D chalcogenides [9], as well as the existing issues and challenges, in particular, in van der Waals solids. This work was partly supported by the Russian Science Foundation (grant 22-19-00766). 1. A.V. Kolobov, J. Tominaga, Chalcogenides: metastability and phase-change phenomena, Springer, 2012 2. A.V. Kolobov, J. Tominaga, Two-dimensional transition-metal dichalcogenides, Springer, 2016 3. A.V. Kolobov, M. Krbal, P. Fons et al., Nature Chemistry, 3 (2011) 311 4. A.V. Kolobov, P. Fons, Y. Saito et al., ACS Omega 2 (2017) 6223 5. Y. Saito, A.V. Kolobov, P. Fons et al., Appl. Phys. Lett. 114 (2019) 132102 6. A.V. Kolobov, P. Fons, J. Tominaga et al., J. Phys. Chem. C, 118 (2014) 10249 7. A.V. Kolobov, P. Fons, Y. Saito, Phys. Stat. Sol. - RRL, 15 (2021) 2000418 8. A.V. Kolobov, V.G. Kuznetsov, P. Fons et al., Phys. Stat. Sol. - RRL, 15 (2021) 2100358 9. A.V. Kolobov, Phys. Rev. B, 94 (2016) 094114