Mechanism of the ZnGa2S4 monolayer formation on an NaCl surface

摘要

Abstract: The calculations are carried out by the use of semiempirical methods of molecular orbital local combination of atom orbital. The calculations results show that Zn will deposit more probable on interstitial sites on 1.5 angstroms distances from the substratum surface with 0.3 eV bond energy, and its position is energetically instable. For Ga atoms, beside interstitial sites (r$-0$/ $EQ 0.5 angstroms, E$-0$/ $EQ $MIN@2.3 eV) there are NaCl lattice sites and bond center (r$-0$/ $EQ 1.5 angstroms, E$-0$/ $EQ $MIN@1.8 eV). The S atoms will trap by the crystalline lattice sites with 5.0 - 5.5 eV bond energy at 2.5 angstroms distance. Moreover, its penetration to monolayer surface through interstitial sites at r$-0$/ $EQ 4 angstroms distance is possible. In spite of Zn at ZnGa$-2$/S$-4$/ compound sputtering evaporates the most effectively, the probability of its deposition in the first layer on NaCl substratum is low. Ga and S atoms will substitute Zn atoms, which transit inside lattice or to the next monolayers. The Ga$-2$/S structure formation with S localization on sites and Ga in interstitial sites of NaCl lattice is expected.!7