Abstracts Book - IMRC 2018

• SD1-O028 Invited Talk
DISCOVERING A NOVEL NANOMETRIC CUBIC PHASE IN
MONOCHALCOGENIDE SEMICONDUCTORS – THEORY MEETS
EXPERIMENT
Guy Makov 1
1 Ben-Gurion University of the Negev, Ilse Katz Institue for nanoscale Science & Technology,
Israel.
A new nanometric cubic binary phase was recently discovered in tin
monosulfide. However, its identification and characterization proved
challenging and was confirmed by a combination of experimental and
theoretical modelling to be a previously unknown, low symmetry 64-atom cubic
structure. 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 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 the properties of which
are being explored to explain the nanocrystal growth mechanisms. This talk will
focus on the results of our calculations and their interplay with experimental
studies.
Keywords: Monochalcogenide semiconductors, Electronic properties, Novel materials
Presenting authors email: makovg@bgu.ac.il