Guy Makov
Ilse Katz Institute for Nanoscale Science and Technology, Israel
Title: A novel nanometric cubic phase in monochalcogenide semiconductors – theory and experiment
Biography
Biography: Guy Makov
Abstract
A new nanometric cubic binary phase has been synthesized in the tin monoselenide and monosulfide systems, π-SnSe, π-SnS, as cube shaped nanoparticles. This new phase has unusual structural properties reflected in a large, 64-atom unit cell and promising optical properties due to the larger band gap and non-centrosymmetric structure of the crystal. It is also environmentally advantageous. This exciting discovery has already led to the publication of over 25 studies in less than 2 years. However, interpretation of the structure, bonding, stability and electronic properties has proven challenging. By introducing by ab-initio density functional calculations the structure, atomic positions and band gaps of these phases were determined and found to be in very good agreement with experimental measurements. Advanced theoretical studies including density functional calculations of the phonon spectrum that determined these phases to be mechanically stable and energetically close to competing structures such as rock salt and orthorhombic. Furthermore theory predicts that the monochalcogenides will exhibit other, as yet experimentally undiscovered, novel phases with promising properties. This study overview the latest results of our calculations and experimental studies.