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Title: Optical Absorbance Enhancement in PbS QD/Cinnamate Ligand Complexes

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.
ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [3] ; ORCiD logo [4] ;  [5] ;  [4] ; ORCiD logo [1] ; ORCiD logo [6] ;  [2] ; ORCiD logo [4]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States)
  3. Univ. of Chicago, Chicago, IL (United States)
  4. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  5. Colorado School of Mines, Golden, CO (United States)
  6. National Renewable Energy Lab. (NREL), Golden, CO (United States); Colorado School of Mines, Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1948-7185
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 9; Journal Issue: 12; Journal ID: ISSN 1948-7185
American Chemical Society
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; quantum dots; quantum dot/ligand interactions; tunable properties; ligand exchange
OSTI Identifier: