Shuhong Xu, Chunlei Wang, Yiping Cui
Influence of ligand and solvent on characters of ZnTe clusters
Journal of Molecular Structure 938 (2009) 133–136
Based on zinc blende and wurtzite structures of experimental ZnTe nanocrystals, four clusters (Zn3Te3, (Zn3Te3)2, (Zn3Te3)3, Zn4Te4) and many Te–Zn-ligand structures were originally investigated using (density functional theory) DFT/B3LYP/Lanl2dz method. First, from analysis of conformation, we believed that tetrahedron Zn4Te4 with TD symmetry and hexagon Zn3Te3 structures may be the smallest units of ZnTe nanocrystals. Second, calculated Raman spectra of four structures were 110–160 cm−1, which was significant for experiment. Third, studied with (time-dependent density functional theory) TDDFT, absorption spectra of four clusters in solvent were more consistent with experimental results, compared with those without solvent. The wavelengths of the calculated absorption peaks gradually shift to red in order Zn3Te3, (Zn3Te3)2 and (Zn3Te3)3, which is induced by quantum size effect. Additionally, we also testified that the transitions of four structures were from Highest Occupied Molecular Orbital (HOMO) to Lower Unoccupied Molecular Orbital (LUMO), which was d–p transition. Four, analysis of Te–Zn-ligand clusters showed that there was no vibration among Te–Zn–S in theory. Besides, all Te–Zn-ligand clusters had similar characters because the main influence of ligands came from thiol. Finally, we deduced that both solvent and ligand made absorption spectra shift to blue.
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