Optical Absorbance Enhancement in PbS QD/Cinnamate Ligand Complexes
Autor: | Giulia Galli, Brett W. McNichols, Arthur J. Nozik, Chloe V. Castaneda, Matthew C. Beard, Noah D. Bronstein, Daniel M. Kroupa, Nicholas P. Brawand, Márton Vörös, Alan Sellinger |
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Rok vydání: | 2018 |
Předmět: |
Materials science
Ligand Ab initio Dangling bond 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Ring (chemistry) Photochemistry 01 natural sciences 0104 chemical sciences Colloid Quantum dot General Materials Science Physical and Theoretical Chemistry Absorption (chemistry) 0210 nano-technology HOMO/LUMO |
Zdroj: | The journal of physical chemistry letters. 9(12) |
ISSN: | 1948-7185 |
Popis: | We studied the optical absorption enhancement in colloidal suspensions of PbS quantum dots (QD) upon ligand exchange from oleate to a series of cinnamate ligands. By combining experiments and ab initio simulations, we elucidate physical parameters that govern the optical absorption enhancement. We find that, within the cinnamate/PbS QD system, the optical absorption enhancement scales linearly with the electronic gap of the ligand, indicating that the ligand/QD coupling occurs equally efficient between the QD and ligand HOMO and their respective LUMO levels. Disruption of the conjugation that connects the aromatic ring and its substituents to the QD core causes a reduction of the electronic coupling. Our results further support the notion that the ligand/QD complex should be considered as a distinct chemical system with emergent behavior rather than a QD core with ligands whose sole purpose is to passivate surface dangling bonds and prevent agglomeration. |
Databáze: | OpenAIRE |
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