Regensburg 2019 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 12: Frontiers of Electronic-Structure Theory: Focus on the Interface Challenge III (joint session O/CPP/DS/TT)
DS 12.9: Vortrag
Dienstag, 2. April 2019, 12:45–13:00, H9
Discovering a novel nanometric cubic phase in monochalcogenide semiconductors - Theory meets experiment — •Guy Makov1,2, Uri Argaman1, Elad Segev2, Ran Abutbul1,2, and Yuval Golan1,2 — 1Dept. of Materials, Ben-Gurion University, Beer-Sheva, Israel — 2Ilse Katz Institute of nanoscience, Ben-Gurion University, Beer-Sheva, Israel
A new nanometric cubic binary phase with a low-symmetry 64-atom cubic structure was recently discovered in tin monosulfide. Subsequently, this phase was synthesized and identified in tin monoselenide and posited to exist in germanium monosulfide and monoselenide based on density functional theory total energy calculations. A series of computational and experimental studies have identified promising optical properties due to the larger bandgap and non-centrosymmetric structure of the crystal. The structure, atomic positions, band gaps and vibrational spectra of these phases were determined by ab-initio density functional calculations and found to be in very good agreement with experimental measurements. The phases were determined to be mechanically stable from ab-initio phonon spectra and energetically close to competing structures such as rhombohedral and orthorhombic. Surface energy calculations indicate that the particles must be stabilized by ligand adsorption. Ligand surface properties are explored to explain the nanocrystal growth mechanisms. This talk will focus on the results of our calculations on surface and bulk properties and their interplay with experimental studies.