Elucidating the role of surface passivating ligand structural parameters in hole wave function delocalization in semiconductor cluster molecules

dc.contributor.authorTeunis, Meghan B.
dc.contributor.authorNagaraju, Mulpuri
dc.contributor.authorDutta, Poulami
dc.contributor.authorPu, Jingzhi
dc.contributor.authorMuhoberac, Barry B.
dc.contributor.authorSardar, Rajesh
dc.contributor.authorAgarwal, Mangilal
dc.contributor.departmentChemistry and Chemical Biology, School of Scienceen_US
dc.date.accessioned2018-04-24T16:11:17Z
dc.date.available2018-04-24T16:11:17Z
dc.date.issued2017-10
dc.description.abstractThis article describes the mechanisms underlying electronic interactions between surface passivating ligands and (CdSe)34 semiconductor cluster molecules (SCMs) that facilitate band-gap engineering through the delocalization of hole wave functions without altering their inorganic core. We show here both experimentally and through density functional theory calculations that the expansion of the hole wave function beyond the SCM boundary into the ligand monolayer depends not only on the pre-binding energetic alignment of interfacial orbitals between the SCM and surface passivating ligands but is also strongly influenced by definable ligand structural parameters such as the extent of their π-conjugation [π-delocalization energy; pyrene (Py), anthracene (Anth), naphthalene (Naph), and phenyl (Ph)], binding mode [dithiocarbamate (DTC, –NH–CS2−), carboxylate (–COO−), and amine (–NH2)], and binding head group [–SH, –SeH, and –TeH]. We observe an unprecedentedly large ∼650 meV red-shift in the lowest energy optical absorption band of (CdSe)34 SCMs upon passivating their surface with Py-DTC ligands and the trend is found to be Ph- < Naph- < Anth- < Py-DTC. This shift is reversible upon removal of Py-DTC by triethylphosphine gold(I) chloride treatment at room temperature. Furthermore, we performed temperature-dependent (80–300 K) photoluminescence lifetime measurements, which show longer lifetime at lower temperature, suggesting a strong influence of hole wave function delocalization rather than carrier trapping and/or phonon-mediated relaxation. Taken together, knowledge of how ligands electronically interact with the SCM surface is crucial to semiconductor nanomaterial research in general because it allows the tuning of electronic properties of nanomaterials for better charge separation and enhanced charge transfer, which in turn will increase optoelectronic device and photocatalytic efficiencies.en_US
dc.eprint.versionAuthor's manuscripten_US
dc.identifier.citationTeunis, M. B., Nagaraju, M., Dutta, P., Pu, J., Muhoberac, B. B., Sardar, R., & Agarwal, M. (2017). Elucidating the role of surface passivating ligand structural parameters in hole wave function delocalization in semiconductor cluster molecules. Nanoscale, 9(37), 14127–14138. https://doi.org/10.1039/C7NR04874Ben_US
dc.identifier.urihttps://hdl.handle.net/1805/15899
dc.language.isoenen_US
dc.publisherRSCen_US
dc.relation.isversionof10.1039/C7NR04874Ben_US
dc.relation.journalNanoscaleen_US
dc.rightsPublisher Policyen_US
dc.sourceAuthoren_US
dc.subjectsurface passivating ligandsen_US
dc.subjectsemiconductor cluster moleculesen_US
dc.subjectdelocalizationen_US
dc.titleElucidating the role of surface passivating ligand structural parameters in hole wave function delocalization in semiconductor cluster moleculesen_US
dc.typeArticleen_US
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Teunis_2017_elucidating.pdf
Size:
1.22 MB
Format:
Adobe Portable Document Format
Description:
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.99 KB
Format:
Item-specific license agreed upon to submission
Description: