Size-Scalable Near-Infrared Photoluminescence in Gold Monolayer Protected Clusters

Patrick J. Herbert, Christopher J. Ackerson, Kenneth L. Knappenberger

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


Near-infrared photoluminescence of a series of three gold monolayer protected clusters (MPCs) with volumes spanning 50-200 Å3 was studied by using variable-temperature photoluminescence (VT-PL) spectroscopy. The three MPCs, which included Au20(SC8H9)15-diglyme, Au25(SC8H9)18, and Au38(SC12H25)24, all exhibited temperature-dependent intensities that reflected a few-millielectronvolt energy gap that separated bright emissive and dark nonradiative electronic states. All clusters showed increased PL intensities upon raising the sample temperature from 4.5 K to a cluster-specific value, upon which increased sample temperature resulted in emission quenching. The increased PL in the low-temperature range is attributed to thermally activated carrier transfer from dark to bright states. The quenching at elevated temperatures is attributed to nonradiative vibrational relaxation through Au-Au stretching of the MPCs metal core. Importantly, the results show evidence of a common and size scalable metal-centered intraband PL mechanism that is general for ultrasmall metal nanoclusters, which are expected to show nonscalable optical properties.

Original languageEnglish (US)
Pages (from-to)7531-7536
Number of pages6
JournalJournal of Physical Chemistry Letters
Issue number31
StatePublished - Aug 12 2021

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Physical and Theoretical Chemistry


Dive into the research topics of 'Size-Scalable Near-Infrared Photoluminescence in Gold Monolayer Protected Clusters'. Together they form a unique fingerprint.

Cite this