Effects of sulfur substitutional impurities on (ZnO)n clusters (n=4-12) using density functional theory

In this theoretical work we used Density Functional Theory, B3LYP and LanI2dz basis set to study (ZnO)(n) nanoclusters (n = 4-12) with sulfur as substitutional impurity. We study the effects when one single atom of the substituent is placed at each oxygen location within each (ZnO)(n) nanocluster. We analyze all structures by measuring bond length and angle sizes and discuss the relationship of the structural effects after the substituent addition as well as effects in binding energy and electronic properties on each variant. Relative energies were calculated between the different cluster families and our results were compared with prior works. Binding energy increased in all the structures after the substituent was applied and with a few exceptional cases HOMO-LUMO gap energy decreased when compared to the pristine form results. (C) 2011 Elsevier B.V. All rights reserved.