SYNTHESIS AND PROPERTIES OF NANOCRYSTALLINE π-SnS – A NEW CUBIC PHASE OF TIN SULPHIDE

Ran Eitan Abutbul ^1,3 Elad Segev ¹ Leila Zeiri ^1,2 Vladimir Ezersky ¹ Guy Makov ^1,3 Yuval Golan ^1,3

¹Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva
²Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva
³Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva

We report on the synthesis of the newly discovered cubic phase of tin sulfide π-SnS and compare its properties to the well-known phase of tin sulfide, a-SnS. Shape control was achieved by variation of synthesis parameters, resulting in cubic, rhombic dodecahedral and tetrahedral shapes of the π-SnS nanoparticles. X-ray diffraction provided authentication of the proposed model and refined determination of the lattice parameter a=11.595 Å. Raman spectroscopy showed substantial shift towards higher energies and peak splitting for π-SnS. Optical absorption spectroscopy indicated an indirect band gap of 1.53 eV, in good agreement with density functional theory (DFT) calculations indicating a band gap greater than that of a-SnS. DFT total energy calculations show that the π-SnS phase is energetically similar to α-SnS, and significantly more stable than the hypothetical ideal rocksalt structure of SnS.