Metal-ligand interaction in ternary AgxInxSy clusters - (TD)DFT study

Comprehensive studies on the impact of 1-propanethiol ligands on the structural and optical properties of the AgxInxSy clusters have been discussed in this work. The studies were performed within a density functional theory and the time-dependent density functional theory framework for a group of model structures including metal thiolate complexes as well as two groups of larger models as the Ag2In2S8 and Ag3In3S10 clusters. Obtained results revealed that optical properties of the AgxInxSy clusters are dominated by the nonbonding electrons and the n→π* transitions characterized by weak oscillator strengths and charge transfer nature. It was also shown that structural reconstruction related to detachment of the alkane chains may be responsible for formation of the non-emissive species due to the rearrangement of atoms and formation of the S-S bridges and its higher oligomers. All of the results are consistent with the experimental results gained by single particle spectroscopy putting a new light on the photo-physics of the ternary I-III-VI quantum dots.